IMIA Paper – Modern Skyscrapers – July 2012 IMIA …...IMIA Paper – Modern Skyscrapers –2012...

IMIA Paper – Modern Skyscrapers – July 2012

WGP 76 (12)

IMIA Working Group Paper MODERN SKYSCRAPERS

IMIA Conference 2012, Rio de Janeiro

Working Group Tom Wylie (Zurich UK) Jeremy Terndrup (Willis) Joe Haddad (Precision s.a.l.) Oliver Hautefeuille (SCOR) Gero Stenzel (Partner Re) Rupert Travis (Cunningham Lindsey) Eric Brault (AXA) Chairman:

Mladen Šošić (Nationale Suisse)

EC Sponsor: Christoph Hoch (Munich Re)

IMIA Paper – Modern Skyscrapers –2012

Table of Contents

1. Executive Summary ............................................................................... 3 2. Introduction ............................................................................................ 4

2.1 Historic Development of Modern Skyscrapers ..................................................... 4

2.2 An Overview of Iconic Skyscrapers ..................................................................... 5

2.3 The Social and Ecological Impact of Tall Buildings ........................................... 13

3. Structure, Material and Building Technique ......................................... 14

3.1 Foundations and the Excavation Pit .................................................................. 14

3.2 Structure of the Main Skeleton, Design and Material ......................................... 17

3.3 Façade, Design Material and Anchoring ............................................................ 19

3.4 Fit-Out and Finishing Works .............................................................................. 22

3.5 Mechanical and Electrical Equipment in Building .............................................. 23

4. Risk Management ................................................................................ 26

4.1 Passive Risk Management measures................................................................ 26

4.2 Active Risk Management Measures .................................................................. 29

5. Insurance Cover ................................................................................... 35

5.1 CAR – Property and Material Damage Cover .................................................... 35

5.2 Third Party Liability (TPL) Cover ........................................................................ 35

5.3 Delay in Start-up (DSU) / Advanced Loss of Profit (ALoP) Covers .................... 36

6. Underwriting Considerations ................................................................ 37

6.1 Underwriting Information.................................................................................... 37

6.2 Special Considerations for Material Damage Cover (CAR) ............................... 38

6.3 Special Considerations for Third Party Liability (TPL) ....................................... 40

6.4 Special Considerations for Delay in Start-Up (DSU / ALoP) .............................. 41

6.5 Skyscrapers and Decennial / Inherent Defect Insurance (IDI) ........................... 41

6.6 MPL Assessment for Skyscrapers ..................................................................... 43

7. Claims, Loss Control and Loss Prevention / Mitigation measures ...... 45

7.1 Introduction ........................................................................................................ 45

7.2 Loss Prevention / Mitigation measures .............................................................. 47

7.3 Claims and Loss Experiences ........................................................................... 49

7.4 Fit-Out: Claims Issues ....................................................................................... 50


1. Executive Summary

We have observed some substantial changes in use and purpose of Skyscrapers over the last 100 years. We can also see that the locations of the new Skyscrapers are geographically shifting more and more eastwards, towards the new and emerging economies in Asia.

We know that historically the development of high-rise buildings was closely connected with the need for more living and working space in overcrowded US metropolises and agglomerations (e.g. New York, Chicago…).

Whilst today this remains one of the driving forces, it is no longer the main one. We see more and more Iconic Skyscrapers mushrooming all over places where there is no problem with lack of space (e.g. Dubai, Mecca, Taipei, Kuala Lumpur, Abu Dhabi, Seoul, or even London…). It is clear that today’s Skyscrapers are increasingly built as a statement as opposed to the response to a practical need. They are the representative Icons of a certain city, society, culture, company or individual.

As a result Skyscrapers architects have sought to design more stunning architectural forms and this in turn has driven engineers to develop the new and impressive high-tech materials necessary to build such structures. The buildings must ultimately draw the attention; no longer is it enough simply to be the tallest in cityscapes increasingly dominated by very tall buildings. Today’s statements are made by expensive forms and materials which ultimately increases the investments and the value of such projects.

For us, as the insurance and reinsurance community, this development brings a transformation of the two very important risk factors:

a. The value at risk is soaring and the projects need higher insurance capacity

b. The complexity of the work and therefore the risks in construction are increasing

We wanted with this paper to outline the new situation as we see it, and to highlight some of the insurance considerations and solutions that can be applied as this trend towards the construction of Iconic Skyscrapers develops worldwide.

For the benefit of all IMIA members we have tried to collect the important aspects, even though we repeat some older, well known facts about the insurance of high rise buildings which remain valid today.

We hope this paper will find a place in our community as a good technical fundament and a stimulus for further thinking, discussions, leading to the development of ever more appropriate insurance solutions for high rise buildings and modern Skyscrapers.


2. Introduction

2.1 Historic Development of Modern Skyscrapers In the late 19th century, the first skyscrapers would have been typically an office building of more than 10 storeys. The concept was undoubtedly originated in the USA, in Chicago and in New York, where space was limited and where the best option was to increase the height of the buildings. The Home Insurance Building in Chicago was perhaps the first skyscraper in the world. Built in 1884-1885 its height was 42 m/10 storeys. Designed by Major William Le Baron Jenney, a graduate of l’Ecole Centrale des Arts et Manufactures de Paris, the structural skeleton was a bolted steel frame without bracing supporting the loads coming from the walls and the slabs, founded on a raft. This led to what is known as the “Chicago Skeleton”.

As a consequence of further developments in construction engineering and progress in the steel industry, the American Security Building was built in New York by Bruce Price 10 years later. This was a 20 storey/ 92 metre building, but in this case the frame was braced and riveted.

Major William Le Baron Jenney established what became known as the First Chicago School to which also belonged Louis Sullivan and Daniel Burnham, both trained with Le Baron Jenney. It is worth noting that the Wainwright building built in Saint Louis, Missouri in 1881 designed by Louis Sullivan is according to some the first true skyscraper. Between 1880 and 1920 another architectural school known as “les Beaux Arts”, by reference to Les Beaux Arts of Paris developed. Its influence can be seen on buildings such as the Park Row and Flatiron buildings in New York. The Flatiron building, (22 storeys/87 m), was designed by Daniel Burnham and the engineer Fuller (it was also known as the Fuller Building). At this time construction in Chicago was limited to 10 storeys, however, no such restriction existed in New York. Consequently New York emerged as the leading city for skyscrapers, welcoming visitors with the sight of its unique skyline.

Later a group of architects and engineers that included Mies Von der Rohe, I M Pei and Fazlur Khan (Skidmore Owings and Merrill) became known as the International School and developed skyscrapers further in the Fifties and beyond. Progress in technologies and materials allowed different construction methods and architectural design changed dramatically; curtain wall, glass panel, and tube support. Skyscrapers would not have been possible without the development of the elevator, by Elisha Graves Otis in 1851. Further progress in design, materials and construction methods has enabled the transition from skyscraper to the “super tall” and unique structures that we see in skylines across the world today.

Such is the rapid progress that these buildings constantly provide challenges for all involved, including the insurance industry. Many buildings by nature incorporate prototypical or innovative elements and often local construction codes cannot keep pace with such development.

A good example is the case of the John Hancock tower in Boston. This is an interesting case to study from an underwriting perspective, as the damage which affected this building could be covered by a modern construction policy wording.

The building was completed in 1972, to a height of 241m/60 storeys. At the time the building was the tenth tallest in the world. It has been reported that the building suffered problems with the foundations, structural failures and an excessive failure of the glass curtain wall. While glass breakage is not unusual for this type of building, the problem was such that all the glass panels of the curtain wall required replacement after completion.


During the investigation it was also discovered that the buildings dynamic response to strong winds was excessive, creating a swaying motion. The problem required the addition of two mass dampers as well as additional stiffening. An historic church dating from 1877 and underground utility lines were also damaged as a result of the foundation works. It required 3 years to solve all of the problems, during that time the building was unoccupied causing the owner significant consequential loss.

The numerous issues suffered by this building demonstrate clearly the challenges encountered in the construction of tall or super tall buildings. Wind tunnel testing would almost certainly be carried out at the design stage today for similar structures in order to model wind, rain and snow effects on the building. Historically skyscrapers were mostly used as commercial offices, today many buildings are constructed with multiple occupancies in mind; offices, hotel, residential, shopping. This paper aims to provide insurance professionals with an understanding of the risks associated with modern skyscraper construction. 2.2 An Overview of Iconic Skyscrapers Following a relatively quiet period, construction of mega skyscrapers recommenced in the years following 2000. Not only are these buildings tall, they are iconic, displaying striking and ground-breaking design. Many of the new iconic buildings are no longer simply offices; they now incorporate retail, commercial, hotels, residential and even transportation hubs. It is no longer simply about building taller, it is about building so called “vertical cities”. Following the events of 9/11 and the destruction of the Twin Towers in New York, there is an emphasis on designing stronger and safer buildings. Most new skyscrapers incorporate many of the NIST (National Institute of Standards and Technology) Recommendations. Buildings are now also constructed with sustainability and environmental issues in mind. New, improved and recycled materials are contributing to a new age in construction. Tall buildings continue to make statements however the statement is no longer just about the tallest as can be seen by unusual designs such as Marina Bay Sands in Singapore and Capital Gate in Abu Dhabi. Buildings are now incorporating “sky lobbies” with integral and even rooftop gardens. Rain and waste water is being captured and recycled. New developments in façade design simultaneously reduce the impact of wind, heat and direct sunlight, innovative and intelligent building management systems interact with these to generate renewable energy or capture the natural heat and light to reduce the energy needs of the building. Many buildings now have their own co generation plants and wind turbines as well as solar panels or hydrogen fuel cells, contributing to their own energy usage. The following demonstrates the main features of some iconic structures recently completed and under construction, together with developments in building standards and fire safety.


Burj Khalifa – Dubai (2010) – 829m High Level Facts Constructed in 6 years US 1.5bn, part of Downtown Dubai overall cost of

USD20bn World’s tallest building 163 storeys World’s fastest elevator at 40 mph Construction 45,000 square metres of concrete weighing in excess of

110,000 tonnes 12,000 workers working on it at its peak 100 different nationalities worked on it highlighting the

issues with diversity of language 192 43m deep,1.5m diameter piles Pressurised/air conditioned refuge floors at every 35 floors

Sustainability Condensation will be collected and used for the irrigation

system providing almost 4m litres of water per year Solar power heats 140,000 litres of water per day Pressurised and air conditioned refuge areas every 25 floors

Insurance Challenges Height and wind impact Pumping concrete at a pressure of 200 bars Ensuring this was done successfully and cured properly given the extremes of

heat/cold. Corrosive groundwater

International Commerce Centre - Hong Kong (2010) – 484m High Level Facts Constructed in 8 years USD3.75bn 118 storeys Worlds highest hotel – Ritz Carlton JV with MTR So called “Transit Integrated Tall Building” – transit

connections via Kowloon Station Development to: Hong Kong International Airport Mainland China via High Speed Rail MTR Ferry and buses


Construction First building in Hong Kong to employ shaft grouted friction barrette piling system – 34

piles 76m Diaphragm wall 5 workers killed in work platform incident Sustainability Low emissivity glass reflects ultra violet light and deflects heat Elevators use passenger smart card system allocating lifts to groups of people with

the same floor destination Condensed water fro air conditioning used for toilet flushing or cooling towers Marina Bay Sands - Singapore (2010) – 207m High Level Facts Constructed in 3 years US 8bn 10M Square foot integrated resort 340 metre long rooftop Sky Park 57 storeys Construction Sky park has 66.5m cantilever and 150m long

swimming pool 4.5 metric tonne damper protects cantilever

from human excitation Multi directional bearings protect the Sky Park

structure from 250mm building sway Adjustable jacks maintain the Sky Park against

settlement 80m long 1.7 metric tonne girders lifted by

hydraulic jacks at 14m per hour 50m long piles support the foundations on

reclaimed land within 120m diameter diaphragm wall

Sustainability Double glazed curtain wall façade reduces heat absorption by 20% on the west side. East side planters create microclimate Insurance Challenges Constructed in 3 years 3 buildings connected by the Sky Park, movement of buildings in relation to each

other and the Sky Park in relation to wind impact Huge Cofferdam in reclaimed ground As part of the towers were built at an incline there was always the danger that they

could collapse in on themselves Lifting of the Sky Park Sections


Taipei 101 (2004) – 449m High Level Facts US 1.8bn Includes both indoor and outdoor observatories Elevators are aerodynamic and fully pressurised Construction High performance steel (inc. 8 mega columns) Every 8 floors, outrigger trusses connect the columns to

the building’s core 380no. 80m long piles support the foundations 101 storeys above ground & 5 basement levels Uses a 660t steel pendulum as a damper to reduce the

effect of strong gusts Two additional dampers each weighing 6t sit at the tip of

the tower to prevent wind damage Sustainability Awarded Leadership in Energy and Environmental

Design Platinum Certification Designed to resist 1:2,500 yr earthquake, has already

survived a 6.8 magnitude earthquake during construction in 2002 Double panel glazing reduces heat absorption by 50% Insurance challenges Earthquake and Wind, Height and need to pump concrete to high levels Capital Gate – Abu Dhabi (2011) – 165m High Level Facts US 8bn, 57 storeys Most inclined building in the world at 18 degrees leans more than leaning tower of Pisa at 1.22 deg. 340 metre long rooftop Sky Park Construction 13,200 tonnes of steel including 7,000 tonnes

structural diagrid systems 720 5 tonne diamond shaped diagrids Cantilevered tea lounge at 80m External infinity pool at 19th Pre cambered core, Every floor plate is unique

creating twisting form 490 30m deep piles Sustainability Low Emissivity glass – keeps building cool and

eliminates glare Stainless steel splash keeps 30% of heat away Air is pre cooled between inner and outer facade


Digital Media City Building/Seoul (2015) – 640m

High Level Facts US $2.9bn Tallest observation deck at 540m 10,000m2 interactive aquarium largest in world Construction Bamboo type structure, with heart section left empty,

increases resistance to bending, thus enhancing resistance to earthquakes and wind vibration

Concrete structure clad in glass and aluminium Sustainability Green roof top will provide heat insulation effect Automatic ventilation will aid supply of fresh air and

save energy Internal mirrors will direct sunlight toward lower floors Photovoltaic generation on side walls to provide

power and also act as shading Building energy requirement reduced by up to 65%

Shanghai Tower/Shanghai (2014) – 632m High Level Facts US $2.2bn Due to be 2nd tallest building in world after Burj

Khalifa 9 cylindrical buildings stacked on top of each other

enclosed by an inner glass façade High speed elevators due to be fastest in world Construction Design of glass façade will reduce wind loadings by

24%, which reduces the structural steel by 25% Concrete core with structural steel frame Sustainability Double layered façade will allow building to remain

opaque without associated heat absorption problems Vertical axis wind turbines will generate 350,000 kWh

per year Spiralling parapet collects rainwater used in M&E

systems Restaurants, shops, offices, hotel and residential

spaced throughout the building Refuge area every 9 floors


Abraj Al-Bait Towers/Mecca (2011) – 601m Mecca Royal Clock Hotel Tower High Level Facts US $2bn Currently 2nd tallest building in world after Burj

Khalifa Tallest Hotel in the world Tallest clock tower in the world Largest internal floor area in the world –

1,500,000m2 Each clock face is illuminated by 2m LEDs and

are 40m in diameter, largest clock face in the world

Construction Composite towers form overall building Concrete Frame Two large fires occurred during construction

one burned for over 10 hours Highest tower 120 storeys Insurance Challenges Some residential areas were being let for

occupation whilst construction continued on the floors above

Busan Lotte World Tower Busan, South Korea (2016) – 510m High Level Facts US $4bn 110 storeys Described as a compact city duty to range of

uses/services being incorporated Construction Concrete Frame Sustainability Natural ventilation Thermal regulation Double Skin with louvers Sea water cooling system


Freedom Tower NYC (2013) – 541.3m High Level Facts US $3.2bn, 104 storeys Described as a compact city duty to range of

uses/services being incorporated Xenon lamps will flash the letter ‘N’ for New York,

they will be seen up to 26 miles away Construction Massive redundant steel moment frame paired with a

massive concrete shear wall – provides column free interior spans

Concrete (5,660m3)/Steel (40,800t) First use of 14,000 psi concrete in New York Must bridge a myriad of pre-existing underground

structures including the New York subway. Structural steel used to as permanent formwork

Fire proofing exceeds code requirements structural elements are protected by up to 3m of concrete

Sustainability Geometrical taper of tower reduces wind loads and therefore amount of steel required Individual tenant electricity supply meters are being installed to encourage tenants to

reduce usage. The building will be partially powered by Hydrogen fuel cells Insurance Challenges Operational Subway Basement level structures obstructed foundations

Shard London (2012) – 310m High Level Facts £450m approx 72 habitable floors plus 15 radiator floors in the roof Tallest building in the European Union Designed with WTC collapse findings in mind Construction Concrete Core with Structural Steel Frame Entirely clad in glass Bill Price (WSP) – Designer of the Shard says “Improving

active and passive fire protection, recognising the importance of structural redundancy and providing sufficient means of escape to buildings are the three key areas of change”

Prof Barbara Lane (ARUP Fire Group) says “A huge amount of work has been done with computational analysis to model what’s likely to happen in a fire… traditionally you applied fire protection to a certain fire rating and hope for the best, now we have the tools down to the detail of what joints are being produced…”


Non shattering intumescent paint firmly bonded to steel members Sustainability Designed to use 30% less energy than equivalent buildings Triple glazed, low iron laminated to reduce effects of infra red radiation Features computer controlled glass fibre roller blinds to reduce solar radiation by 95%,

thus reducing the need for air conditioning Night cooling will be used to dissipate heat at night Will include a micro CHP unit to supplement energy usage Insurance Challenges Very tight site with considerable third party exposure Radiator floors fabricated offsite and lifted into position in large units up to crane limits

Songdo City (IBD) South Korea (2015) High Level Facts USD $30-40bn approx over 10 years 1,500 acres of reclaimed land of which

40% will be open spaces 50m sqft of office space, 10m sqft of

retail space, 80,000 apartments CISCO will provide WAN access across

all infrastructure Sustainability All development and construction

related activities mandated to achieve LEED certification

All open spaces optimised to access sunlight and open sky

Electric vehicle charging stations Zero emission buses featuring hydrogen

fuel cells Canals will be filled with sea water to

lower potable water demand Storm water runoff to be stored and used as required Vegetated green roofs to trap storm water and increase biodiversity LED traffic lights and energy efficient pumps and motors Centralised pneumatic waste collection system for wet/dry waste thus eliminating

requirement for waste removal vehicles PV cells used extensively to provide energy 75% of construction waste to be recycled. Low VOC materials incorporated in all

buildings Sustainability Issues Embodied energy within structure – The higher you go the worse the problem Elevators, Building Services, Access & Egress Agreement and suitability of ratings systems e.g. BREEAM/LEED etc.


2.3 The Social and Ecological Impact of Tall Buildings On the 11th September 2001 the world watched in horror as the events in lower Manhattan were relayed live on television. Even before the dust had settled, the debate had begun. This terrible human tragedy brought many to question the wisdom of man’s fascination with ever taller and more spectacular buildings and some even predicted that the “age of skyscraper” was at an end. More than a decade later, many very tall buildings were under construction and still more are being planned. In reality as the raw wounds from this tragedy began to heal, human nature dictates that we analyse these events and look for the lessons to be learned. Elsewhere in this paper you will find reference to new designs, new construction methods and new materials all aimed at developing safer, more ecologically friendly, and you guessed it, taller buildings. Man’s love affair with the Skyscraper is still very much alive. The events of 9.11 were relayed instantly to the world, however, whilst not perhaps not so obvious, there are many other ways in which tall buildings have had an effect on society. In the face of high demand and lack of building land, in the 1960’s many city authorities turned to high rise buildings as a solution to their social housing problems. The detrimental effect of such experiments in terms of psychological and physical health and lack of social cohesion is now well documented. Many such “tower block estates” have since been demolished and many of those that remain have sadly become ghettos housing dysfunctional and troubled communities plagued by excessive levels of crime and welfare issues. The high cost of maintenance and the relatively high cost of construction have meant that new high rise developments are now aimed at more affluent elements of society or businesses who can afford to pay the high rents required. The affluent and the office worker however are not immune to these health issues and modern developments have included many initiatives designed to combat their perceived causes. Some of the most ambitious projects include varied occupancy, mixing residential apartments with office space, retail outlets and hotels, all in the same tower, the ”Shard” in London being a recent example. With the addition of sports facilities and community centres, it is thought that this mixed function will create a more realistic “village” environment, thereby alleviating the sense of isolation and alienation that is thought to have led to many of the health and social issues observed in the past. The experiments in high rise social housing in the sixties saw many tower block estates build on the fringes of towns and cities without adequate transport systems, thus adding to the sense of isolation. Most new developments are nearer the city centres or deliberately sited close to existing or newly developed transport infrastructure. The construction of very large structures in a confined space, often on top of or close to operating rail and road networks does, however pose some considerable technical, logistical and risk management challenges. Whilst the world struggles to achieve agreement on the issues of Global Warming and Climate Change, it is clear that many Governments are increasingly seeking to control the “Carbon Footprint” of individuals and companies either through legislation or taxation. The energy consumed in operating a tall building in terms of power, light, and air conditioning systems alone are significant however in addition to this, the energy expended and the


emissions produced in making the buildings must also be considered. The materials most likely to be utilized in large quantities for the construction of a very tall building will be Concrete, Steel and Glass all of which require a significantly higher energy consumption than traditional materials. These issues are increasingly being considered by architects and engineers when designing today’s tall buildings whereby the relatively high energy cost of some construction materials can be to some extent offset by innovative design giving the building a more sustainable profile over its lifetime. The inclusion of thermal flues in the facade design can be used to control temperature without the use of air conditioning. The inclusion of Photovoltaic panels and wind turbines for electricity generation will reduce the need for external power. The orientation of the building and the design of the facade can greatly reduce the need for artificial lighting. Whatever drives the demand for Skyscrapers, it is clear that such demand exists, however it is also evident that social and ecological issues are more and more influencing the design of these buildings. It is no longer simply a question of being the tallest; they must also be user friendly, environmentally friendly and sustainable. The new generation of tall buildings will undoubtedly bring challenges for the construction industry as well as for their Insurers. 3. Structure, Material and Building Technique 3.1 Foundations and the Excavation Pit Skyscraper foundations are considerably more complex than those for normal buildings. The complexity brought about by their height and weight can be further exacerbated by design specific factors, the nature of the soil, exposure to wind and earthquake, intended use and their location in relation to surrounding property. Different project elements are frequently divided among several contractors and consultants with specialists chosen for the foundations. Depending on the nature of the structure, the type of foundation and the characteristics of the ground, the value of the foundation / excavation can according to construction industry research be circa 7.5% of the total project value. Managing quality and risk at this stage is crucial for the future success of the project, consequently, the developer or client should seek to hire a world class project and or programme manager in addition to experienced contractors and consultants. Geotechnical Parameters The client will usually provide the tendering contractors with a detailed geotechnical report highlighting the outcome of the investigation by geotechnical consultants incorporating their recommendations. There may be a degree of uncertainty in the composition of the ground beneath a building irrespective of the extent and detail of any site investigation and associated laboratory testing. For this reason a worst case scenario should be considered until it can be shown otherwise. Contractors and their own or externally appointed geotechnical and structural engineers may use this report as the basis for further investigation with a view to managing out risk, verifying modelling presumptions in relation to dead and live loads and finding the best foundation solution to suit the specific circumstances. Foundation Structure


The foundation is the supporting layer of a structure. The purpose of the foundation is to spread the various loads (wind, seismic, dead and live) from the structure into the ground. Different factors can influence the type and dimension of the foundations; soil type and stiffness, water content, void ratio, bulk density, angle of repose, cohesion, porosity to name but a few. Characteristics of the ground can also experience change due to the geological history or previous construction activities. This can be a particular issue in areas of seismic activity where the soil can become liquefied and / or on shores of seas, lakes and rivers where there may be a constant ebb and flow or rising and lowering of a river which influences the adjacent soil composition. Additionally, the location in relation to other structures, weight of the building including all fixtures and fittings, usage, the dimensions of the building and the loads for wind and earthquake are important elements which are taken into consideration. For high-rise buildings a deep foundation is necessary. It is used to transfer the huge load from the structure through upper weaker layers of soil to the stronger deeper layers. Foundations are formed by first clearing the site of previous structures or in the case of a previously unused location, of trees, shrubs and other obstacles. The next step is to create an excavation. The nature of the excavation will depend on many of the aforementioned factors. In the case of a skyscraper, simple battered slopes will not suffice and a temporary or permanent retaining wall will need to be installed The retaining wall may serve several functions; supporting the excavation, protecting the excavation from the lateral forces of the ground and the hydrostatic pressure of groundwater, protecting adjacent structures against settlement and in some cases even providing additional vertical support to the structure. There are many different types of retaining walls:

Interlocking sheet piles; these can be temporary or permanent Contiguous, secant piled walls, the latter more likely to be used in soft/wet soils Diaphragm walls; particularly used in soft ground with high groundwater and/or

adjacent to other structures Crosswalls; often used in addition to one of the above where is a particularly high

exposure to adjacent properties Strutting, propping ground anchoring and bracing; used as extensive temporary supports in deep foundations in addition to retaining walls, where there is high risk of excavation failure and/or particularly high exposure to adjacent structures. Again depending upon influencing factors and the management of risk, excavations and basements may be formed by ether the top down method, the bottom up method or a combination of the two. Top down has the advantage of being more economic as there is a time saving element, it is also safer as the basement floor slabs are constructed as the excavation progresses, strengthening the excavation as it deepens. This method is typically used in deep foundations close to adjacent properties and/or in poor ground. The weight and thickness of the base slab is crucial as this will protect the foundation from heave or uplift caused by high water pressure. It may be necessary to install a dewatering system to keep the excavation dry from groundwater seeping in or rainwater. Following or during the excavation, dependent upon the excavation method, piles for the structure’s foundation will be necessary.

http://en.wikipedia.org/wiki/Architectural_structure


Number and type of piles will be dependent upon numerous factors. In some cases the piles are up to 1.5 meters in diameter and inserted 80 meters into the ground to reach bedrock. The nature and positioning of the piles will also be influenced by the positioning of the main supporting columns of the structure. In some extreme cases, ground improvements will have to be made prior to piling by injecting grout or a deep soil mix into soft ground or fissures. Where there is a threat of seismic activity there may be the necessity to install additional safety features such as viscous dampers within the foundation to protect the structure. For underwriters it is important to have an understanding of the ground conditions and how the construction parties will deal with the challenges. In many cases highly engineered temporary works are necessary and it is important that specialist engineers with strong knowledge in the area of ground engineering/geo-techniques are employed for this role. Managing risk at this stage is crucial for the success of the structural works that are to follow, but also to protect surrounding properties and the public from the potentially disastrous impact of a failed excavation or foundation. Foundations structures and piles should be checked by an independent checking engineer. Where there is the potential for high groundwater, piezo-meters should be installed throughout the site to monitor the levels and a suitable dewatering utilized, ideally with back up pumps. Where extensive dewatering is needed due to high groundwater, it may also be necessary to strategically position recharge wells around the site to protect other properties from settlement caused by removing too much water from the ground. In areas where there is a potential for flash flooding or overflow from adjacent watercourses the excavation perimeter should be surrounded by a suitable flood protection scheme. Dilapidation surveys should be carried out on adjacent properties to establish the nature and extent of any existing damage and the potential for future damage. In some cases it may be necessary to underpin, prop or grout to provide potentially vulnerable properties with additional support. A monitoring regime should be introduced by the construction parties, ideally with the capability to employ remote and real time monitoring of the settlement caused by the works. Suitable predetermined alarm/action levels should be in place, coupled with an emergency response plan. Typically in the case of coverage for skyscrapers clauses should be considered which address the following specific areas: Piling Dewatering Vibration, weakening

or removal of support Dilapidation

Figure 1: Shanghai, China : Possible failure of the foundation, June 27, 2009


Figure 2: Moscow, Russia: Excavation / cantilevered walls

3.2 Structure of the Main Skeleton, Design and Material The development of Skyscrapers has been possible because of the progress made in the materials and the development of new structural systems allowing improved technical performance and also improved financial models, which have attracted more interests from the property developers. The Council on Tall Buildings and Urban Habitat (CTBUH) has conducted a survey of the tallest buildings and has noted, for example, that the John Hancock building in Chicago uses 25% less structural steel per unit floor area than the Empire state building. If in the early days of Skyscrapers steel played an important role, today concrete, and especially high performance concrete seems to be key in the project development and definition. To give the reader some figures: according to the same CTBUH journal, of the 100 tallest buildings the number using steel has reduced by at least 15% each decade since 1970, and in 2010 only 22% of the tallest building are steel. The key issues with high performance concrete (high performance concrete is reinforced concrete with a compressive strength at 28 days in excess of 50 MPa) relate to the quality of the material and the expertise of the contractors. Only a few of whom are familiar with these concretes. The controls on site must be quite strict and without compromise. The columns of The Coeur Defense towers in the business district of Paris have a diameter of 1,10m and used a high performance concrete of 80 MPa. When it comes to steel, the quality of the material is with the suppliers. On site the main concern will be on the various assemblies. This is like giant meccano, however as often these projects take place in a confined urban environment, logistics and third party exposures are an important consideration. In respect of structural systems, it is possible to define 6 categories:

The framed tube: system of rigid frames (flatiron building in 1903) The bundled tube: combination of framed tubes (Sears towers, 1974)


Tube in tube: central and peripheral tubes (World Trade Centre in NY, 1972) Diagonalised: strussed tubes, diagrids/braced frames (Alcoa bld. in Chicago) Core plus outrigger: central lateral system linked to the perimeter system through

outriggers (Petronas Tower, 1999 –Taipei 101, 2003 ) Hybrid: combined use of any of the above systems Today more than 70% of skyscrapers have adopted a core + outrigger structural system. Structural walls are indispensable elements of tall buildings, sustaining vertical gravity and horizontal earthquake effects and wind loads. Local or standard building codes are not usually suitable for the construction of these giants. Any attempt to apply them would likely be incompatible with the architectural designs suggesting a quantity of materials that would lead to an uneconomical model. It is therefore necessary for the design team to model the building and test it in a wind tunnel to assess the local loads and the likely deformations of the structure. Usually these tests are not limited to wind but can include, when applicable, rain, snow and of course hurricane simulations. Wind engineering is essential for skyscrapers and the risks cannot be adequately reviewed if these tests have not been properly conducted. Alan G Davenport, a pioneer in wind engineering (1932-2009) was influential in these works when working at the University of Western Ontario. Mr Davenport used mathematical models and experiments in wind tunnels to study the limits to which a building can lean before collapsing, how a building can sway back and forth and the consequent effects on partitions, elevators, occupants, etc. At the Boundary Layer Wind Tunnel laboratory (BLWTL) he and his teams have conducted several analyses and invented the shock absorbers. Returning to the John Hancock tower in Boston: This building did not have the full benefit of a wind tunnel analysis. Alan G Davenport warned that in gales, the tower could collapse despite the presence of a tuned mass damper. The vulnerable side of the building was then reinforced with extra diagonal steel bracing. Because of the sway noted in skyscrapers it would be difficult to imagine that the Taipei 101 and many other buildings could have been realised without their tuned mass dampers. Not just because of wind but also considering the Earthquake exposures. Earthquakes represent a special challenge to the engineers but looking at the experiences and the history, especially coming from Japan, the results are satisfactory and positive with regard to the protection of life even if the structure usually does suffer during an earthquake. It is however important for a construction underwriter to look at the problems emerging from these loads (earthquake or wind) during the various construction stages. The wind analysis is very often conducted with a view to understanding how the building will behave when it is completed. However for example the cladding of the building may require further tests to make sure that during the construction stages, the wind load distribution will not generate unexpected problems. Various types of skeleton structures are shown in Figure 3 below:


Superframe Steel frame Vertical Truss

Tube in tube Bundled tube Exterior braced Frame tube Steel tube, ex WTC

Steel frame/belts

Tuned Mass Damper

3.3 Façade, Design Material and Anchoring The earliest towers were constructed of bricks and mortar, stone and later concrete, incorporating wood, steel, aluminium, or UPVC framed windows. As building projects became more sophisticated architecturally, and taller, these earlier methods were no longer practicable and thus were replaced by “curtain walls”. The cladding of High Rise buildings are now made of glass, aluminium, or stone. They are erected in place attached to brackets which are in turn attached to the building’s concrete or steel structures.

Some decades ago the cost of the cladding or building’s façade was less than 10% of the total construction cost. That percentage has increased to range between 15% and 20%.

Even though the value or cost of the non-load bearing cladding / façade has increased substantially, the weight of these elements has reduced due to advances in the type and nature of the materials used.


System The façade / cladding systems comprise the external building envelope or the outer finish. These have evolved over time to reflect the ambitions of the developers and the creative and innovative talents of the modern architects. It would seem this is limited only by budget constraints or construction methodology Key factors which will affect the characteristics of the cladding / façade systems include; climatic conditions, support and anchorage systems, owner’s “taste”, maintenance services, ventilation or air-circulation system. The dimensions of the individual external wall elements, forming part of the external building envelope, are designed to fit between two respective structural floors, the main objectives being:

Water-tightness, Aesthetics, Wind, Privacy Thermal protection (including control of sunlight entry), Reduction in noise-level, and Strength / durability.

There are four different groups and their sub-groups of Façade systems / Cladding systems existing. They are (though not an exhaustive list):

Traditional - Brick façade (e.g. Empire State building, Chrysler building, etc.) - Marble panel system

Ventilated Façade - Aluminium, stone, ceramics, fibre reinforced concrete

(Non-load bearing) Curtain wall Glass Material Weights Flat glass used for window panels – the weight depends on the glass thickness: ¼ of an inch thick glass weighs about 3lbs/ft² ½ of an inch thick glass weighs about 6.4lbs/ft² Adding coatings to the glass in order to protect it and tint, would also increase the weight of the glass panel. Building Material

Aluminium – has become the material-of-choice for the outer frames. Window Panes – made of high-grade glass filled with noble gases and a surface

coating in order to reflect infrared light. Laminated Glass “Sandwich” Panels – one of the primary materials used in façade systems of a

building are so called “sandwich” panels or also known as “composite” panels. - Sandwich or Composite panels are thermal insulating material. These panels

consist of two thin metal facings/sheets (i.e. outer “skin”), usually steel or aluminium, bonded to an inner core of thermal insulating material of varying thickness. This system includes joints and supports. They are factory-engineered or factory-assembled systems, or can be assembled on-situ. There are two groups of such panels, combustible and non-combustible.

- The combustible panels include: Expanded Polystyrene (EPS), Extruded Polystyrene (XPS), Polyurethane (PUR), Polyisocyanurate (PIR), Phenolic Foam (PF)


- The non-combustible panels include: Mineral Wool, Rock Fibre (MWRF), Glass fibre (MWGF), Foamed Glass (Cellular Glass)

There is great interest in the combustible-type panels because they are the most widely used in buildings like apartment/residential, hotels, office/commercial, hospitals.

The combustible panels are widely used / installed in countries situated in the Middle East and the Arabian Gulf peninsula due to the harsh climatic conditions, characterized by high temperature all year-long especially between June and September. The most widely used panels are the polystyrene and the polyurethane panels for many reasons, to name a few (a) low installation cost, (b) easy in handling and installation, and (c) strength/durability. However, it has shown over the past few decades, through loss-experience, that such panels have contributed to the severity of damage resulting from fire. The disadvantages of these panels are several, such as high flashover and rapid proliferation (through cores and voids), generate intense heat, large quantities of dense smoke, and toxic gases (e.g. CO, HCN, etc.), and too dangerous to fight and too difficult to extinguish (many firemen lost their lives).

Support and Anchorage System There are different types of anchorage systems, each type is designed in a manner to ensure (a) stability of the respective Cladding / Façade system, (b) a uniform distribution or transfer of vertical and lateral loads, and (c) allow for a differential expansion between the different materials forming the outer finish of the building. These anchorage systems include “gravity” and “lateral” types of connections. Problems encountered with the installation of Cladding / Facades System The unpredictable availability of tower cranes and lifts, weather conditions, delays in completion of works due to poor coordination of façade installations with other sub-contractors’ activities, etc. Poor Workmanship or defective / faulty material introduced during the construction of the system followed by the continuous influence of a wide variety of forces and exposures will, overtime, lead to façade failures. Determining the cause(s) of the Cladding / Façade system’s failures requires in-depth knowledge of the system itself and its support elements, the underlying structural system, the climate and the nature of forces acting on it. Two relevant examples of system’s failures were encountered at the John Hancock tower in Boston and the AMOCO building (now known as the AON Center) in Chicago. Falling Glass Panes in the John Hancock tower in Boston – due to faulty glass windows, glass panes detached from the tower and crashed on the sidewalk few hundred feet down below. It was later confirmed by an independent laboratory that “…the failure of the glass was due to oscillations and repeated thermal stresses caused by the expansion and extraction of the air between the inner and outer glass panels which formed each window; the bonding between the inner glass, reflective material, and outer glass was so stiff that it was transmitting the force to the outer glass (instead of absorbing it), causing the glass to fail” (http://en.wikipedia.org/wiki/John_Hancock_Tower). Figure 4: John Hancock tower in Boston, MA, USA

http://en.wikipedia.org/wiki/John_Hancock_Tower


AMOCO Building (AON Center) in Chicago – the original white Italian marble (known as Carrara) installed was later found to be not suitable for Chicago’s extreme weather conditions. So, almost 15 years later, the tower was re-cladded. The re-cladding almost doubled the weight of the façade. Consequently, the anchorage system was upgraded. The cost of entire job cost USD 80 million, more than half of the tower’s original cost (http://failures.wikispaces.com/Standard+Oil+-+AMOCO+Building+Marble+Facade+Failure). 3.4 Fit-Out and Finishing Works Shell and Core Shell-and-core includes the completed landlord areas comprising main entrance as well as the reception, lift and stair cores, lobbies and toilets. The office floor areas are left as a shell ready for additional fit-out. Category A Fit-Out Category A is typically what the developer provides as part of the rentable office space and usually comprises the following:

Raised floors, Floor coverings, Suspended ceilings Extension of the mechanical and electrical services above the ceiling from the riser

across the rentable space Finishes to the internal face of the external and core walls Window blinds Category B Fit-Out Category B completes the fit-out to the occupier’s / users specific requirements. It can

typically comprise the following:

installation of offices, enhanced finishes conference/meeting room facilities, reception area, enhanced services / specialist

lighting IT and AV installations, kitchen area, furniture Turnkey Fit-Out This is the least common type. The property is fitted out to a standard ready for occupation – it can cover everything including the furniture. Developers may undertake a turnkey fit-out in order to sublet to occupiers who do not want the time and cost of their own fit-out or as an incentive to potential occupiers. Insurance At this stage in any project the risk of fire and water damage is enhanced. Fire and the resultant smoke and heat damage and the water used to extinguish the fire all cause considerable damage. The risk of a fire occurring in the first place is enhanced with the introduction of many and various potentially combustible materials, packaging and trades. Trades at this point may include painter/decorators, plumbers and electricians. Consequently there is a potentially dangerous combination of paints, solvents and hot work together with the aforementioned combustible materials, all of which must be carefully managed. It is also often the case that it is necessary to disable fire detection and sprinkler systems whilst certain aspects of fit out work are being undertaken. Training of personnel to deal with these circumstances is critical. Another factor to consider is whether the developer or the tenant will undertake the fit out. If the developer is doing this, their people and contractors will be familiar with the building

http://failures.wikispaces.com/Standard+Oil+-+AMOCO+Building+Marble+Facade+Failure


and its layout. The introduction of a different team employed by the tenant brings with it interface issues which often lead to claims. Additionally, this introduces a new dimension from the coverage perspective in relation to existing structures and how they are treated for insurance purposes within contract and policy documents as well as legal implications as to who is liable and which, if any policy, will respond. In the UK, the Joint Code of Practice for Prevention of Fire on Construction Sites has been developed by collaboration between the construction industry, the loss prevention council, the fire authorities and the Association of British Insurers. This has gone a long way towards improving risk management against the risk of fire. The code is now on its 7th edition and has also been adapted in other territories. Where this does not apply Munich Re endorsement 112, Fire Fighting Facilities is often applied. Another factor which has exacerbated fire claims or at least the cost of such claims is the disproportionate values that may exist on a newly fitted out bank or commodities trading floor. Extensive high cost IT equipment and fibre optic cabling add to the cost, but the cabling itself can also acts a conduit contributing to the spread of the fire. Water damage is also an increasing problem as highlighted in the claims section of this paper. There have been some recent examples of buildings being occupied whilst physical construction of upper shell and core is still being undertaken, this has many additional exposure implications, not least of which is life safety. 3.5 Mechanical and Electrical Equipment in Building With the growing sophistication of buildings, advancements in the functionalities and capacities of the different mechanical equipment required in order to render the High Rise buildings habitable and safe have accompanied man’s vision of future towers. Elevators and Tuned Mass Dampers are two of examples of mechanical equipment designed and installed to:

transport hundreds of people across floors in the shortest possible time support the buildings stability against winds and ground movements Mechanical floors are incorporated in the design of buildings where such equipment is installed to service the upper floors as well as act as a fire-break between the lower and the upper floors. Fire fighting water pumps and water reservoirs are usually installed on these floors. The value of such equipment and its installation is estimated to be 15% to 20% of the total contract value. The installation of electrical and mechanical equipment usually follows completion of the civil works. Such works include the installation of machinery and equipment and their ancillary works such as the drainage piping, potable and non-potable water pipes and ducting etc. This section of the works typically involves the construction and installation of the following equipment / machinery: Transportation Systems Elevators

The invention of the elevator was a precondition to the development of skyscrapers since it is the only logical means capable of transporting large numbers of people


throughout the building. Elevator shafts are usually, but not exceptionally part of the skyscraper’s central core.

Escalators These would be used to transfer people at lower levels between lobbies and upper

lobbies/mezzanines or between the floors of a transport hub or mall which may form the lower floors or basements of a skyscraper.

There are number of factors which affect the design of elevators and escalators. These factors include; location, traffic patterns, physical requirements, safety, and aesthetic preferences.

Location – is important because elevators and escalators should be situated where they can be easily seen by the general public. In addition, the up and down escalator traffic should be physically separated, and should not lead into confined spaces. Traffic Patterns (taking into account number and nature of occupants and number of floors) – simply relate to the movement of people from one floor to another or guiding visitors towards a main exit or an exhibit. Furthermore, the carrying capacity of the escalator must be designed taking into account the anticipated peak traffic demand. As an example, elevators accessing residential floors will have different needs to those servicing office or hotel areas. Physical Requirements – include the vertical and horizontal distance to be spanned. Thus these will determine the pitch of the escalator and its actual length and in the case of the elevator may determine speed and indeed whether the elevator can practically service all floors from the bottom to the top. Some buildings have elevators which service specific predetermined floors, in some cases it may be necessary to change elevators at an upper floor to reach higher floors. The ability of the structure to support the heavy components may occasionally present a design challenge. Safety - Speed, braking, dissipation of pressure, failure of building management systems and degree of service if any during an emergency situation need to be taken into account. Aesthetic Preference - important as these structures should blend in with the overall finishing and decorative works. Heating, Ventilation, and Air-Conditioning (HVAC): Heaters or Boilers for humidity control Blowers and Fans ventilation Air-Conditioning for temperature control and constant air supply Pumps, Ductworks Safety Equipment Fire Alarms and Smoke Detection Devices – conforming to NFPA 72 Fire Fighting and Suppression Systems

- Sprinkler Systems – conforming to NFPA 13 - Manual Fire Extinguishers – e.g. Dry chemical, CO2 - Gas flooding systems

Tuned Mass Damper - A device in the form of either a large concrete block or a steel body installed in

skyscrapers in order to reduce the amplitude of mechanical vibrations for instance caused by earthquakes or winds. These help mitigate or prevent damage or structural failures in buildings.


- The Damper moves in the opposite direction to the “resonance frequency” oscillations of the building structure by means of a fluid, pendulum, springs.

- In the mid-seventies, the occupants of the upper floor of the John Hancock tower in Boston suffered from motion-sickness when the tower swayed in the wind. To stabilize the tower’s movement, the contractor installed two 300-ton weights Tuned Mass-Dampers on the 58th floor of the building. Each is made up of a steel box filled with lead and attached to the steel frame of the tower by means of springs and shock absorbers and rests on a steel plate. The steel plate is covered with lubricant in order to permit the Tuned Mass-Damper to slide freely. When the tower sways due to wind, the weights remain still allowing the floor to slide underneath them, the springs and shock absorbers take hold, tugging the tower back into position (http://en.wikipedia.org/wiki/John_Hancock_Tower).

Electrical and Water Supply Emergency Power Supply – shall conform to NFPA 110

- Standby Diesel Engine-Generators Electric Power Supply and Components – shall conform with NFPA 70

- Power Transformers - High- and Low-Voltage Switchgears - Metering Equipment

Water Pumps - Sprinkler System – shall conform with NFPA 20 - Potable and Non-Potable water supply - Sewage Ejectors, also known as Sewage Pumps, or Solid Waste Pumps.

Chiller Plants - Chillers produce chilled water for the building for various usages. - Chillers could be air-cooled, water-cooled or evaporative-cooled.

Mechanical Floor In addition to the structural support and elevator

management, the Mechanical Floors are used to house the HVAC systems, Water Tanks, Water Pumps, Water Tanks, Chiller Plants, etc.

As a rule of thumb, skyscrapers require a Mechanical Floor every 10 floors. However, this number may vary.

Mechanical Floors are counted in the building’s floor-numbering (according to some Building Codes).

They are accessed by Service Elevators. Delivering water to the upper floors for normal and

emergency use presents an important constraint to the designers of skyscrapers since the ground based pumps can only usually deliver water up to a dozen floors or so. Water is necessary for the people occupying the building, for air conditioning, for equipment cooling, and for fire-fighting, to name a few. Therefore, the Water Pumps on each Mechanical Floor act as a relay to the next group up. The truss sections (made of triangular struts) are the mechanical floors.

Figure 5: Construction showing mechanical floor

http://en.wikipedia.org/wiki/John_Hancock_Tower


4. Risk Management What is Risk Management? In this context, Risk Management is the continuous process of identification, evaluation, monitoring and control of risk and exposures both prior to and during construction in order to prevent the happening of or to mitigate the impact of a physical loss to property and bodily injury to people, on and adjacent to the construction site. The Project Management usually delegates the task and responsibility of Risk Management to a group or a team of individuals whose role is to ensure that risk is managed out to the extent possible and/or evaluate the methods of transferring the risk and the potential cost. 4.1 Passive Risk Management measures

The Impact on Risk Management at the Design Stage In modern construction projects developers and contractors commence the process of managing out risk at the earliest stage. Designers are required to comply with a variety of building codes and standards. Such standards will also vary according to geographical location, for example locations particularly exposed to wind and earthquake. Designers will be addressing a huge number of issues in this respect which require risk management input including: Height, Shape, Weight, Foundations, Façade, Sustainability Environmental impact Construction Costs, Life safety, Usage, Fire and explosion, Water systems Weather and climate, Building management systems Geographical location, Materials Increasingly, modern skyscrapers are subjected to wind tunnel tests to establish the impact of wind on the structure and the surrounding area. Shape, height and facade designs are influenced by wind tunnel tests and adapted to mitigate the effect of wind and rain. Even without the influence of major storms, tall buildings are subject to a degree of sway. This must be curbed in order to avoid excessive sway, which in turn will put long term stresses on the structural fabric of the building and also cause problems for the occupiers. In locations exposed to earthquake, buildings will need to be fitted with dampeners and shock absorbers to minimise the impact of quakes and aftershocks. The common denominator for safety in buildings, regardless of geographical location and natural catastrophe exposures, is fire, both in terms of protection of the structure and protection of the occupiers or users. The ever increasing desire to build taller requires lighter components and larger open floor plates – This may lead to weaker buildings with large open areas thus allowing fire to travel faster. The main causes of fire are:

Faulty electrical, heating & ventilation systems Cooking area malfunction Ignitable materials.

In the wake of several major terrorist incidents restriction of vehicular access/proximity to the building and blast protection are also important.


The following are some of the important design considerations that architects and engineers will focus on:

Non shattering intumescent paint Separate access and egress routes Redundancy in fire suppression systems Fire resistant boarding and concrete cladding to structural steel members instead of

intumescent paints and foams e.g. more robust Off-site building monitoring/Situational awareness Backup water supplies Fortified elevators Higher fire resistance standards for structural members Fire detection, warning and fighting facilities Access and facilities for the emergency services Safe zones Choice of materials in relation to fire resistance Education of residents & tenants of tall buildings Many of these and more were subject of the National Institute of Standards and Technology (NIST) recommendations which were introduce following the tragic events of 9/11 (see below): 18 out of 30 recommen-dations have not been fully applied, including one demanding that buildings be designed against progressive collapse. ASCE asked to revise minimum design load standards to tackle pro-gressive collapse – This has not been done. Relevant UK & Euro-codes are being reviewed but this has not completed yet. Experts believe that the proposals would only have made a difference to WTC 7 which collapsed as a result of fire rather than a combination of impact and fire.

More consideration is required as to how structural connections are designed and will perform. It is probable that ‘resiliency’ design will only be applied in special circumstances.

Figure 6: Illustration of recommended technical features


NIST Recommendations Prevent progressive collapse through consensus standards/methodology – Code

change provides greater structural integrity only Nationally accepted performance standards for Wind Tunnel testing and estimation

of wind loads – Software available but standard not changed Criterion to be developed to enhance performance of tall buildings by limiting how

much they sway under lateral load design conditions – No action taken Improve construction classification and fire rating requirements – Fire resistance

rating increased by one hour Establish a capability for studying and testing components, assemblies, and systems

under realistic fire and load conditions – No action taken Develop criteria, test methods and standards for in service performance of sprayed

fire-resistive materials used to protect structural components – Bond strength for fireproofing increased seven fold

Adopt and use the of the ‘structural frame’ approach to fire resistance ratings – Explicit adoption of structural frame approach

Enhance fire resistance of structures by requiring a performance objective that uncontrolled building fires result in burnout without partial or global (total) collapse – Best practice guidelines but no code changes

Performance based standards rather than prescriptive design methods and tools and methods to evaluate fire performance of whole system – No action taken

Development and evaluation of new fire resistive coating materials – Standard test for new materials introduced

Performance and suitability of high performance materials be evaluated under conditions expected in building fires – No action taken

Enhance the performance and redundancy of active fire protection systems in buildings to accommodate the greater risks associated with building height and population – Code change to require two suppliers for sprinklers

Fire alarm and communication systems be developed to provide continuous, reliable and accurate information – No action taken

Enhance the quantity and types of information provided at fire/emergency command stations in buildings – Building information card introduced

Provide facilities to communicate real time information to first responders off site – No action taken

Public Agencies and Non Profit Organisations should develop public education programmes – Guidance documents for disabled persons only

Fully include consideration for evacuation of occupants into building designs, including thought on counter flows caused by first responders – Code changes demanding additional exit stairway, wider stairways, use of lifts for evacuation

Egress systems be to designed to maximise remoteness of egress components without negatively impacting the average travel distance – Code changes focussed on min distances between exit stairways and luminous markings

Building Owners, Managers and Emergency responders develop joint plans – Standard updated formalising information criterion

Evaluate all current and next generation evacuation technologies – Standard for high-rise external evacuation devices

Installation of fire protected and structurally hardened elevators in tall buildings – Min of one fire service access lift

Installation, inspection and testing of communication systems – Approved radio coverage for emergency services


Improvements and detailed procedures for gathering, processing and delivering critical information to enhance situational awareness of emergency responders – No action taken

Procedures to guarantee uninterrupted operation of C2 systems – Code change increasing size of command centre

Encourage Non-governmental and quasi-governmental to use building and fire safety codes – No action taken

Aggressive enforcement of building code criteria in relation to egress and sprinkler requirements in existing buildings – Code changed with regard to luminous markings

Building owners to retain documentation over the whole life of a building - No action taken

Clarify the role of the ‘Design Professional in Charge’ - No action taken Continued education for design professionals - No action taken Develop and deliver short courses for computational fire dynamics, thermo-structural

analysis - No action taken.

Changes in Legislation & Regulation In the U.K. changes to Building Regulations from 2004 stipulate that any designers of large and more complex Class 3 buildings must undertake a “systematic risk assessment” that not only takes account of all normal events that should be expected during the lifetime of the building, but also abnormal events. The same approach has been adopted in Euro-Codes. Regulatory Reform (Fire Safety) Order 2005 – Makes the client, such as the Chief Executive of the bank occupying the building, principally responsible for response to a fire.

4.2 Active Risk Management Measures

The Impact on Risk Management during the Construction Stage Once the architects and consultants have, as far as possible, mitigated risk during the design phase and engineers have taken it a step further by adapting the design for construction, it is the turn of the contractors and their engineers and consultants to apply risk management during the construction phase. It is usual to establish a risk register at an early stage in the development process. This becomes a live document which is regularly updated by parties allocated to each area. Such parties should be accountable and have ownership for any risk identified, evaluated and registered, they should then become responsible for ensuring that the particular risk is mitigated, eradicated or transferred. Ideally, management of the risk register should be a shared responsibility, this will ensure for example that the contractor or any sub-contractor does not increase risk, inadvertently or otherwise through value engineering or change in method. Ultimately, the goal of all parties is to complete the building without any loss or damage to property, loss of life or injury to personnel and to hand over a project that meets the developer’s or client’s specification and is fit for purpose for the end user. During construction of a skyscraper the most common exposures from the perspective of engineering insurers are many and varied:

Excavation & Foundation – Collapse, inundation, storm, failure of foundation (due to faulty workmanship or design for example) and earthquake.

Material storage – Fire, explosion, theft, accidental damage (during lifting and handling) or malicious damage, inundation, storm and earthquake


Plant and equipment – Collapse (e.g. scaffolding or crane), fire, explosion, theft, accidental or malicious damage, inundation, storm and earthquake.

Superstructure (Shell & Core) – Collapse, fire, explosion, impact, accidental (during lifting and handling) or malicious damage, water damage (due to leaking pipes), failure of systems (e.g. methods of connecting/installing structural steel sections), storm and earthquake

Fitting Out (all aspects including Electrical and mechanical) – Fire, explosion, accidental or malicious damage, water damage, failure of equipment (particularly electrical and mechanical equipment)

Consequently all of the above need to be addressed and supervised by the on-site personnel.

Risk Alleviation Measures

Monitoring of settlement; with action as appropriate, inclinometers, additional propping/support etc.

Flood protection scheme; dewatering system with standby pumps, elevated perimeter to prevent ingress of flood waters, piezo-meters to monitor groundwater

Careful selection and control of storage areas; suitable means of fire prevention and fire fighting, well spaced and compartmentalized storage areas, above level of expected flood, protected/sheltered from the elements (storm, sunlight, heat, cold, sand, salt water environment etc)

Quality control of concrete batching and application; robust testing ad supervision regime

Traffic control; controlled movement and separation of vehicles Maintenance and inspection of vehicles and equipment Site security; encompassing controlled entry and exit, fencing/hoarding, CCTV

surveillance, 24/7 security guards and site illumination Quality control of materials and equipment; robust inspection and testing regime Supervision and inspection of workmanship Storm preparedness; alarms/procedure, evacuation plan Adherence to lifting and handling procedures Adherence to guidelines in relation to use of heat and naked flame; “permit to work”

system adopted and rigorously enforced and complied with ( are cleared of loose and combustible materials, “spotter” working with welder, portable extinguisher on hand, use of non combustible mat, fire checks carried out at regular half hour intervals afterwards)

Adherence to health and safety procedures; Safety induction, use of personal protective equipment (hard hats, protective glasses, boots, gloves etc) and high visibility clothing, floors voids clearly signed, fenced and covered (utilisation of temporary plinths). Shafts and façade openings are particularly hazardous. Additionally, falling from heights is a major cause of injury, as such it should be ensured that workers use safety harnesses at all times when working at height.

General housekeeping; storage of materials and equipment within the building should be minimized and waste materials such as packaging removed at regular intervals (at least daily from the building and weekly from the site).

Signage; clear and well positioned, standardized (symbols rather than or in addition to words) and in multiple languages if necessary.

Water Damage Avoidance Plan; Quality assurance and control, supervision, training, installation of drainage and bunding, clearly defined testing process, audible alarms,


leak detection, security patrols, emergency/mitigation plan in the event of an incident etc. (see CIREG water damage guidance note)

Fire Fighting Measures The project schedule should ensure the early installation and operation of: Automatic fire detection systems Automatic smoke detection systems Hose Reels Permanent fire escape stairs, including fire-resistant doors, railings and permanent

walls Water hydrants, must be clear of obstructions and suitably marked Adequate water supply for fire fighting purposes Portable and wheeled fire extinguishers; the portable fire extinguishers must be wall-

mounted and suitably marked; Lightning conductors Standby power generators Means of communication with the Public Fire Brigade or the Civil Defense In addition to the above mentioned points, it is of paramount importance to involve the human element in this aspect. There should be on site a Fire Fighting and Safety Coordinator heading a team of sufficient number of trained and experienced personnel whose main function is to ensure, on scheduled basis, that all of the aforementioned points are in place, operative, and suitably maintained throughout the construction phase and until handover. Fire Brigade and Civil Defence – Does the local Fire Brigade or Civil Defence have the proper equipment to handle fires on the top floors of the skyscraper? - How high does their fire truck ladder reach? - Which floor? - What is the response time of the Fire Brigade or the Civil Defence? - How are they notified or alerted of any fire incident on site? - Were or are they involved in any regular training offered on site to the on-site Safety and Fire Fighting Teams? Portable Fire Extinguishers – The portable extinguishers must be wall-mounted or placed on flat stable object such as a table. It must be at least 500mm off the ground and are accessible, i.e. without any obstacles or objects which might be in the way of the person reaching out for one in an emergency case. Furthermore, routine checks and maintenance must be maintained in order to ensure its preparedness to operate during any emergency. The checks and their dates are usually noted on the label stuck to the extinguisher. Automatic Sprinkler System – It is highly recommended that the automatic sprinkler system is commissioned, tested, and made operational prior to the commencement of the finishing and decoration works. The term operational shall mean that the system’s pumps, pressure gauges, valves, etc. have been commissioned and tested and are filled with water. The two main reasons are:

Testing of the piping system involves filling it with (clean or potable) water and keeping it under pressure for at least 24 hours in order to identify any leaky joints or valves. If this testing is carried out during or shortly before or after completing the “finishing” phase, then if a leak happens, then damage to the property including the furniture and decorative materials would be experienced.

If a fire breaks out inside the building, then the system would be ready to respond and to mitigate the growth and spread of the fire.

What is usually discovered following the investigation of a fire incident, is that:


The system was not filled with water (at the time of the incident). The insured contractor may interpret the term operational as referring only to successful commissioning and testing of the system. Having to fill it with water is a different story.

Some contractors refuse to fill the system with water and to pressurize it fearing that if a leak were to happen (usually overnight) they would be faced with a water damage loss prior to handover. However, these same contractors tend to overlook, intentionally or otherwise, the fact that water in the automatic sprinkler system would help mitigate the growth and spread of the fire. One should really think and consider which is more critical in terms of the severity of the loss.

Water Supply for Fire-Fighting – Lack of sufficient water supply on the construction site for fire fighting purposes is often observed following a risk inspection. Fire fighting water tanks with sufficient capacities should be maintained and be kept filled with water. The water on site available for construction purposes should not be accounted with that for fire fighting purposes. Following the completion of the superstructure of the building, water tanks are installed on the roof, the technical / mechanical floor(s), and the street level ground.

Figure 7: Storage area in the basement of a building under construction clearly demonstrating a lack of Risk Management! The fire hazard is increased, but water damage would also be inevitable should the basement be flooded.

Figure 9: Miami, FL, US: Protection of the site Figure 10: Moscow, Russia: Protection of the / access control site / access control

Figure 8: Temporary Offsite storage showing properly stored construction material. All construction materials are lifted off the ground and an adequate aisle space is maintained.


The photos below demonstrate that waste inside and outside the buildings are kept for days and even weeks before they are disposed of.

Figure 11: Finishing and decorative material waste (Source: Joseph Haddad)

Figure 14: The “No Smoking” sign is inadequate because it is missing the symbol (top right). Also, in the presence of various nationalities working on the construction site, the signs need to take than important aspect into account, hence, printed in other

languages. It has been the case that during risk inspections that cigarette buds were found not far from where the “No Smoking” signs are posted. (Source: Joseph Haddad)

Figure 15: “Poor” signage – this message will later disappear when the finishing and painting works commence. Alternative signs need to be prepared. (Source: Joseph Haddad)

Figure 12: This is “formwork” waste inside the building, and is adjacent to the fire escape staircase. If this waste catches fire, it will restrain workers from escaping and will restrict or prevent access to the top floors. (Source: Joseph Haddad)

Figure 13: A utility shaft left uncovered; scaffolding as well as plumbing and firefighting system pipes lay in the background hence presenting an unsafe working environment for workers and an obstacle to access. (Source: Joseph Haddad)


Figures 16: Utility shafts

Figure 17: Wall-mounted Dry Chemical powder fire extinguishers, however, must be clear of obstructions. (Source: Joseph Haddad)

Figure 18: Dry Chemical Powder Fire Extinguishers left on the ground without suitable maintenance. They must be wall-mounted, protected from impact, maintained, and visible to personnel. (Source: Joseph Haddad)

Figure 19: These 2 x 72m3 capacity GRP water tanks were erected on the technical / mechanical floor of a tower building. (Source: Joseph Haddad)

Figure 20: Hose Reels – A minimum of two pieces per floor are installed and they must be operative as the construction of the skyscraper progresses. (Please refer to photos under “Pictures” Section below.) (Source: Joseph Haddad)


5. Insurance Cover

Projects for the construction of skyscrapers are insured under conventional Construction ‘All Risks’ policies on a project specific basis for the full duration of the project, including in most cases the maintenance or defects liability period (non renewable/non cancellable). The nature and extent of cover provided can vary from standard Munich Re or Swiss Re forms to bespoke broker/client forms. Cover is arranged in accordance with contract conditions which usually require that the policy is issued in the joint names of the contractor and the owner/principle. The insured parties are often extended to include inter alia contractors and sub contractors of any tier/suppliers, consultants and manufacturers for their onsite physical activities only and financiers/lenders. This reflects the multi party insurable interest in the property insured In most cases all aspects of the project are insured under one policy, this can also be arranged to include tenants/occupiers fit out, however, in some cases separate policies will be arranged for different parts of the project, i.e. foundations, shell and core and fit out. Coverage may range from simple material damage only, to multiple sections including cover for works, existing property, third party liability and delay in start up. A brief description of the cover under each section is provided below. 5.1 CAR – Property and Material Damage Cover Damage to the permanent and temporary works (and materials intended for use in the project) in progress caused by damage (generally defined as physical loss or damage). Cover can be made available for the following if required:

Common user plant and equipment Contractors plant and equipment (usually covered by the contractors own

arrangements) Site huts, temporary accommodation an stores Existing property which is the responsibility of the insured parties by contract or

agreement, cover is often restricted to specified peril and damage arising out of the works being undertaken, however, dependent upon circumstances this may be extended to full ‘All risks’ arising from any cause

Inland transit Offsite fabrication

Usually indemnification can take the form of repair, replacement or reinstatement of the damage.

5.2 Third Party Liability (TPL) Cover

This section provides indemnity against all sums (including claimants costs and expenses) which the insured shall become legally liable to pay in respect of or consequent upon - death of or bodily injury to or illness or disease (including mental injury trauma

anguish or shock) contracted by any person (other than employees of the insured seeking indemnity)

- loss of or damage to property (other than property insured under the Material Damage coverage)

happening or consequent upon a cause occurring during the period of insurance and arising out of or in connection with the project.


Cover is often widened to include:

Interference with traffic or property or any easement, right of air, light, water, support or way or the enjoyment of use thereof by obstruction, trespass loss of amenities, nuisance or any like cause.

5.3 Delay in Start-up (DSU) / Advanced Loss of Profit (ALoP) Covers

Financial losses suffered by the Insured in consequence of delay in the commencement of or interruption or interference with the Business resulting from damage. This cover is also called Delay in Start-Up (DSU). Cover is triggered by damage indemnifiable under the Construction “All Risks” section of the policy and is provided solely for the benefit of the owner/principle and where financiers/lenders are involved, also for their benefit. Coverage, limits and basis of indemnity would be tailored to the project needs and the requirements of financiers. Cover is designed to protect the relevant project parties against a financial consequential loss as a result of project not being completed in time for the originally intended commencement of the business.

The sum insured may incorporate a variety of elements dependent upon the ultimate end use of the building:

Continuing fixed costs Continuing debt servicing Reduction/Loss of profit Reduction/Loss of rent or revenue Additional cost of working Cover can be tailored to incorporate delays arising out of damage at the premises of suppliers and arising out of damage to key items of plant and equipment whether insured under the original contract insurance policy or otherwise. The client should select a suitable indemnity period taking into account the time needed to repair, replace or reinstate the works. This cover cannot be bought on a stand-alone basis, nor can it be bought for the benefit of the contractors. It is however possible for contractors to arrange the project insurance including the Delay In Start Up for the benefit of the appropriate insured parties only. One thing to note is that whilst monetary deductibles apply to all other sections (with the possible exception of Third party injury or death which usually has a nil deductible), a time excess, waiting period or retained liability period expressed in days (normally a minimum of 30) applies to the aspect of ay delay attributable to a cause indemnifiable under the material damage section. It can either be “inclusive” or “exclusive” (the indemnity period is either reduced by the amount or is in excess of it). It is usually also applied not for each and every loss, rather, in the aggregate; although multiple delays may occur a claim may only be made if there is a delay of the scheduled commencement date of operation.


6. Underwriting Considerations 6.1 Underwriting Information Each risk is individual, and this is no less true of high-rise building projects. Technical improvements, new techniques, exciting designs, new materials and combinations of materials lead to new exposures. A prudent underwriter should be aware of what is going on in the constructions industry, not only regarding design, but also on the construction site in terms of new materials and working methods. To enable them to make a proper assessment of risk, underwriters should ideally expect to receive a submission comprising the following: Scope of cover required/policy wording Details of the insured parties and their experience relevant to the work being

undertaken Design/engineering overview Scope of works/description of the project incorporating detailed description of the

foundations (nature, depth, number, type and dimension of piles), structure (dimensions, steel or concrete frame etc.), cladding (glass, steel, composite, stone), fit-out, electrical mechanical plant and any special or unusual features (innovative methods or materials, prototypical features, atria etc.)

Site Plans and drawings Geotechnical conditions Breakdown of the project value Construction bar chart including critical path (especially useful for DSU) Location of risk including overview of natural hazard exposures; storm, flood and

earthquake Description of surrounding and third party property Method statements Details of plant Details of any existing property to be insured equipment Details of site huts, accommodation etc. Overview of approach to health and safety, risk management, quality management

and security Fire safety plan If DSU insurance is required: Overview of project funding Explanation of the composition and calculation of the sum insured Mitigating factors Lead times for materials or critical items Details of availability of suitable resources.


6.2 Special Considerations for Material Damage Cover (CAR) Foundations Geological conditions and the height, weight and footprint of the building will determine the features of the foundations. Unless founded on solid rock, the foundations are likely to be deep and may be highly engineered including cross bracing and diaphragm walls or secant piling, especially if the building is being constructed in a city centre environment adjacent to other buildings and/or is exposed to ground water. In such circumstances extensive piling can also be expected, it is important to know the nature of the piling, including dimensions and method as well as the requirement to bear and spread the buildings load care needs to be taken not to undermine adjacent properties or cause unnecessary damage due to vibration or cracking due to driven piling. Many modern buildings are constructed using externally positioned super columns, this will introduce a further complication. Superstructure and Cladding Tall buildings are subject to huge dynamic loads due to their massive weight and height. Extensive wind tunnel testing should ideally be undertaken to ascertain the effect that wind may have on the structure and the cladding. Constructing such a building necessitates extensive handling exposure with a large number of heavy and s (glass curtain wall panels) sometimes delicate lifts risks being undertaken often in very tight urban environments, care must be taken not to collide with the elements of the structure already positioned. The higher the building reaches into the sky the more the challenges from wind and nature. Pumping and curing concrete in extreme hot or cold environments becomes more difficult and more complex designs create additional engineering and building challenges for the project team. During this phase, the main exposures have been covered, however the biggest albeit remote exposure is collapse. Fit-Out / Electrical Mechanical Fit-out At this stage the building starts to become enclosed and the exposure to wind and the elements reduces considerably. The risk of fire and water damage is enhanced. Fire and the resultant smoke and heat damage and the water used to extinguish the fire all cause considerable damage. The risk of a fire occurring in the first place is enhanced with the introduction of many and various potentially combustible materials, packaging and trades. Trades at this point may include painter/decorators, plumbers, joiners and electricians. Consequently there is a potentially dangerous combination of paints, solvents and hot work together with the aforementioned combustible materials, all of which must be carefully managed. Although risers may be in place fire detection and fighting systems are often not able to be operational at this time as they could be accidentally activated by heat and dust. Fire is the biggest fear and can spread more easily as there will most probably still be floor and wall opening and fire doors and separations may not be installed. Although fire is the big fear and remains very much the Probable Maximum Loss (PML) exposure, such incidents are thankfully few and far between. Fire claims or at least the cost of such claims can be exacerbated by the disproportionate values that may exist on a newly fitted out bank or commodities trading floors. Extensive high cost IT equipment and fibre optic cabling add to the cost, but the cabling itself can also acts a conduit contributing to the spread of the fire. There have been some recent examples of buildings being occupied whist physical construction of upper shell and core is still being undertaken, this has many additional exposure implications, not least of which is life safety.


Water damage is also an increasing problem. The move away from traditional welded copper piping has reduced the fire exposure; however, this has been replaced by push fit installations of composite materials. When these pipes are first subjected to water pressure test this is usually passed. However, when the water system is fully commissioned the constant loads produce a water hammer effect which can result in incorrectly fitted sections becoming ruptured with the resultant release of water cascading over many floors before it can be detected that it is occurring and where the source of the leak is. This then causes substantial damage to floors already fitted out, particularly to wall and floor coverings, electrical and IT installations. Most of the damage occurs within the initial period and it can take up to an hour to identify the source and establish how to stop the water. Claims settlement can be further complicated when it comes to looking at the cause of loss, is it faulty workmanship or latent defect. Another factor to consider is, whether the developer or the tenant will undertake the fit out. If the developer is doing this, their people and contractors will be familiar with the building and its layout. The introduction of a different team employed by the tenant brings with it familiarity and interface issues which often lead to claims. Additionally, this introduces a new dimension from the coverage perspective in relation to existing structures and how they are treated for insurance purposes within contract and policy documents as well as legal implications as to who is liable and which, if any policy will respond. If Latent effects Insurance is purchased, further complications may arise during the defects liability period in terms of policy response. Site Buildings and Accommodation These could include offices, kitchens, canteens, warehousing for storage and in the case of relatively remote locations, extensive workers accommodation. Underwriters need to clarify who owns these buildings, what their value is and to what extent they are to be insured under the project policy. Constructions values are often included within the bill of quantities, however, underwriters also need to clearly establish whether it is also the intention to insure such properties as operational items for the duration of the project and charge the appropriate additional premium. Such items are often overlooked as underwriters and risk engineers focus on the more apparent hazards and exposure, however, these properties can be of poor quality with little in the way of fire resistant qualities, poor spacing and often fire detection and fire fighting capabilities are absent. Underwriters should also establish their proximity to the main structure as fire can easily start within these structures and spread to the building. On and Offsite Storage Again these are often overlooked and again may also feature many of the elements of the above with poor separation/partitioning and housekeeping. Measures should also be taken to ensure that these stores are located above the highest expected flood levels and are adequately protected from a security perspective. Plant Insurance requirements may vary from project to project. In the event that the project insurances are "owner controlled", often only the tower cranes and equipment specifically required for the project are insured under the project policy. In some cases the foundation/ground works aspect will be procured as a separate contract and those works and plant may be insured together under a separate arrangement.


Often contractors have their own plant policies or have the capability to insure plant under their annual policies. Whatever the arrangements, underwriters need to be clear who is responsible for insuring which equipment, what they are insuring under their policy and to what extent. Policies should be clearly worded to support this and rating should be based on appropriate plant values (ideally new replacement values) or hiring charges. On risks of this type plant related exposures are generally relatively minor. In some territories theft can be an issue, often organised where the plant is stolen, quickly moved overseas and then sold. More serious issues relate to hoists and tower cranes. In most territories there are minimum standards to which the erection and operation of such equipment must comply, failure to meet such standards may result in failure of the equipment, resulting in serious damage to the equipment, injury or death to the operator, users and third parties and damage to both the works and surrounding third party property. Fortunately such incidents are rare, however they can happen and when they do they can also have quite an effect on the works programme which in turn may impact upon any Delay in Start Up coverage, provided this has been extended to cover Delay arising out of damage to plant. Natural Perils If the risk is located in a seismic zone with earthquake and tsunami exposure (the latter where close to the sea), or particularly exposed to tropical storms and cyclones, then these risks will need to be considered in addition. Proximity to a river in an area prone to flooding will also need special consideration for protection of the works. Underwriters need to be careful when considering extensions of period in the event that there I a seasonal exposure and the extension may take the risk into for example the next hurricane season, in such cases pro rata additional premiums are likely to be insufficient. Special Clauses: Fire joint code of practice. Munich Re Fire fighting facilities clause or similar, CIREG Water damage guidance note, piling, dewatering, terrorism, SRCC, Time schedule, Munich Re Windstorm and Earthquake endorsements or similar, and Taken into use clause. 6.3 Special Considerations for Third Party Liability (TPL) In the underwriting procedure the following factors should be considered in the process of premium calculation for the TPL exposure: Distance to third parties Fire and / or explosion risk form construction work Height of construction work Type of and method for construction machinery (e.g. cranes) Contractor’s experience and accident record Possibility of the existence of underground laying material such as pipelines and

cables Existence of valuable buildings / structures such as remains or historical monuments Frequency of third parties visits to the site of construction Possibility of ground collapse

Many of these factors can render the TPL exposure of high-rise buildings substantially above average compared with other types of risk: High fire exposure especially at the end of the project


Height of the building due to the type of risk The use of very large cranes Cramped worksites often in city centres Inexperienced contractors may not be of any interest to the actors of the construction

(contractors, engineers and architects) as Projects involving deep excavation / foundations and multiple basements in built-up

areas. The TPL exposure associated with the construction of buildings depends mainly on the environment of the building and on the depth of the excavation works to be carried out. The closer the building is to existing buildings, the greater the risk. Excavation pits have to be stabilized using such measures as slurry walls, soil anchors etc. to prevent any ground movement that could endanger nearby structures. In addition the lowering of the water table can also induce ground settlement around the excavation pit. Loss prevention in respect to these hazards will consist for insurers in checking all geotechnical investigations, making sure that they have been carried out in the planning phase and that recommended measures are correctly implemented. Special clauses: VRWS (Vibration, removal, weakening of support), Underground cables and pipes, Cross liability 6.4 Special Considerations for Delay in Start-Up (DSU / ALoP) The main issues in this respect are access to the site, on site storage and lead times for materials such as cladding and critical heating, ventilation and air conditioning equipment or lifts and escalators. Working days/hours permitted may also be a feature if there is a delay and contractors have to make up lost time. Particularly in large cities, works are often restricted to normal working hours so as not to cause noise pollution and general disruption to local residents and adjacent parties. Such restrictions are often more of an issue during piling and shell and core works Special clauses: Customers Extension, Suppliers Extension, Increase Cost of Working.

6.5 Skyscrapers and Decennial / Inherent Defect Insurance (IDI) Within the panoply of products that the insurance industry can offer for Skyscrapers, it is worth mentioning Decennial or Inherent Defect Insurance (IDI) as it is more commonly known in the English speaking markets. It is certainly important to keep in mind that in most countries, there is a specific liability regime attached to the act of construction especially when it comes to buildings for office, commercial or residential purposes. The parties involved in the construction of a building, contractors, architects or engineers will, from the date of hand-over, have a liability which generally will last for 10 years in respect of defects in the structural works. In some countries /States it can be more: 12 perhaps 15 years. This liability is not limited to the repair of the structural damages but includes also the consequences of the defect. Whilst this liability regime exists in many countries, only a few have imposed a compulsory insurance requirement on the owner. The most well-known of course being France where the compulsory insurance system is perhaps the most comprehensive and certainly the most complicated.


The French liability regime goes beyond the structural defect as it encompasses the “unfitness for purpose”. For a skyscraper issues such as ground settlements and leaning, excessive sway, defective elevators, failing curtain walls and falling glass panels, can be extremely problematic. The French insurance system is designed around what is known as a double trigger: First a first party insurance aimed at covering the owner and all sub-sequent owners (commonly known as “Dommage Ouvrage” DO), then liability insurances to cover separately or in a kind of wrap-up all the participants who participated to the con-struction of the building. This insurance is called “Responsabilité Civile Décennale” or RCD. The DO insurer will indemnify the owner for the Decennial loss and then seek recourse against the various RCD insurers. Over the years several difficulties emerged from this system; what qualifies as a decennial loss; the different legal approaches with regard to unfitness for purpose; the recourse process and the availability of the products for non-French entities. However today the system is working and underwriters have managed to find a way to offer these products to their insureds. In countries where insurance is not compulsory as such, the product sometimes offered is known as Inherent Defect Insurance or IDI. This is a first party insurance aimed at covering the owner, after handover, against defects which damage the structure as well as consequential damage to non structural works, for a period of 10 years. As this product does not offer any liability coverage and therefore may not be of any interest to the constructors (contractors, engineers and architects), underwriters often agree, subject to additional premium, to offer an endorsement waiving any recourse against them. This creates a certain reassurance for the constructing parties, as they know that the cover is in place for their client and that their liability is thus limited. This product is very often seen as an alternative to an Error and Omissions (E&O) cover for professionals of construction or a complement to their existing E&O annual programs. All of these insurances, DO, RCD or IDI, are based on a capitalization model i.e. they will require the payment of a single premium to cover the 10-year period and it is therefore important when fixing the insurance price, to bear mind the possible effects of inflation. Usually the insurance has to be negotiated before the works start as the Decennial underwriters will require a project review by a Technical Inspection Service (or TIS). The TIS is an independent engineering firm which, on behalf of the underwriters, will control, by random inspection, the design as well as the works on site. Their reports go directly to the underwriters and should the TIS conclusion be negative at the time of hand-over, the underwriters may decide to reduce or even to withdraw the cover. It is for this reason difficult to negotiate this cover after completion of the building, as any TIS program will be almost impossible to implement. Because of the particular complexities in Skyscraper construction and design, it is quite common for underwriters to require a complete design review done by independent engineers in addition to the TIS review. Decennial underwriters will in addition seek to review wind tunnel analysis. Another difficulty worth emphasizing, not only to the Underwriting community, but also to developers and their brokers, relates to the foundation. In many instances the foundation works are separately contracted and already completed before the superstructure works contracts are finalized. This can prevent the TIS from adequately performing their role which in turn may prevent the IDI underwriter from insuring the risk. The capacity offered by the market is often not sufficient to cover the full value of these Skyscrapers which today is often in excess of the 1bn USD. Furthermore financiers often require that coverage is extended to include business interruption. Coverage is therefore offered on a first loss limit basis.


Putting together these coverages is complex and in consequence few projects have managed to overcome the hurdles and secure IDI coverage. Some of those which have include: in France: Coeur Defense, the Tower Granite. in Morocco: the minaret of the Hassan II Mosque with its 200 m height in UK: the Shard of Glass Historically the Petronas Tower in Kuala Lumpur, Malaysia is perhaps the first super tall building to have had the benefit of IDI coverage, although cover has now expired as this building is more than 10 years old. The John Hancock tower was a somewhat less successful Skyscraper project, as has been mentioned elsewhere in this paper. Had such coverage been in place at that time, one can only begin to imagine the scale of loss that the underwriters would have sustained. 6.6 MPL Assessment for Skyscrapers Insurance / reinsurance capacity is a limited resource and requires substantial capital. Therefore, optimal deployment of capacity is essential. The realistic and reliable assessment of the loss potential of any one risk is the basis for; Determination of a retention in relation to capital requirements Determination of reinsurance needs Engineering Insurers have historically allocated capacity in accordance with Probable Maximum Loss (PML) Definition of PML Utilized by IMIA “Estimate of the maximum loss which could be sustained by the insurers as a result of any occurrence, considered by the underwriter to be within the realms of probability. This ignores such coincidences and catastrophes as may be possibilities, but which remain highly improbable.” The definition of what is “probable” is in many cases extremely difficult. It is only possible if all the risk information is available and a careful assessment of the situation is made based on the information provided and the experience of the underwriter. Factors to be considered in the PML assessment: Risk Related Factors

Project layout, value concentrations, complexity, technology, materials, construction program, testing phases, human factors (e.g. manufacturer‘s / contractor‘s experience), fire exposure, infrastructure (accessibility, repair facilities, spare parts availability, etc.)

Environmental Factors:

Location; earthquake exposure, water/flood exposure, storm, geology, topography, etc.

Cover Specific Factors:

Extent of cover; inclusion of faulty design, guarantee cover, DSU cover, unclear inclusions/exclusions, limits etc;


The process of calculating the PML considers: What is at risk? What is it worth? How much of it is likely to be damaged, and to what extent?

Answering these three questions in turn provides a systematic approach to the calculation of PML. The calculation needs to be done case by case. Most of the scenarios may lead to a fire / collapse. With potentially huge consequences, especially shortly before completion With the consequence of even a 100% loss, perhaps with the exclusion of foundations, but including removal of debris and other sub limited extension. Normally active and passive fire protection measures would be in place shortly before finish but should not be taken in consideration when calculating the PML. In case of high rise buildings the PML is mainly influenced by fire/explosion and/or Nat Cat. Some considerations regarding PML Scenario might be: Events such as the aircraft attack on The World Trade Centre (WTC) and natural

catastrophes are examples which may not be considered a PML event. A typical (worst-case) scenario for a skyscraper or a high-rise building would be a

complete burnout of the building but without the resultant collapse of the structure. This “accidental” fire event would take place during the “critical phase” of construction of such projects, i.e. the finishing phase; for example, happening only few days prior to the issuance of the Provisional Acceptance Certificate (PAC).

In the worst-case scenario, one could consider that the fire would propagate vertically from floor to floor: Along the façade of the building, Through the openings between floors, Air-conditioning ducts, The internal shafts (such as that of the elevator and the utilities), and/or The staircase (if the fire-resistant doors have not been installed or were kept open). The MPL figure could reach up to 70% or 80% of the total contract value (TCV) plus all relevant sub-limits of the additional covers granted in the CAR policy such as removal of debris, expediting expenses, and professional fees. Fire is without doubt the main exposure for high-rise buildings during construction and operation. Modern high-rise buildings have little in common with other buildings. Additionally, modern buildings now contain a huge amount of telecommunication, switching, air conditioning links etc. Such installations run throughout the building, notwithstanding fire and smoke breaks these often exacerbate the spread of fire, smoke and heat, but also water, during extinguishing activities. In some cases, for example a bank or commodities trading floor will house a concentration of high value fiber optic and other cabling, the consequence of which is that a relatively small fire contained within that floor may result in a disproportionally high claim.

Figure 21 - Edificio Windsor Fire, Madrid, Spain. February 13, 2005. Severe fire during refurbishment activities, temperatures of at least 1260°C


7. Claims, Loss Control and Loss Prevention / Mitigation measures

7.1 Introduction In this section we look at the claims experience on tall buildings, the types of losses which are occurring and the causes that lie behind those incidents. We then go on to examine measures that can be taken to prevent loss, coupled with some guidance on what the underwriters should be looking out for when managing the risk on these projects. This report has been based on the claims histories of the tallest buildings in Europe and the Middle East, which include the losses encountered during construction of the world’s tallest buildings. Before going into detail, a few general observations can be drawn from the statistics. First, there are very few fires – a risk that still has to be taken seriously by construction management due to the risk of injury to personnel, but one where the risk of a claim under a conventional CAR policy is of a different kind. The improvement in the fire risk is partly illustrated by the advent of the Fire Joint Code of Practice, 1997. During the five years which followed, there were no CAR claims on commercial buildings under construction, of more than £1m. In recent years, the insurance market has become increasingly aware of the fact that water is by far the largest problem in CAR/EAR claims, whether it is water escaping from pipes, or weather related incidents. Practically all of the incidents on the claims record of the world’s tallest building under construction were for water damage and this pattern is replicated in the vast majority of the tall building projects examined as part of this study. Consequently, this report will concentrate on the water risk. The report also draws on the conclusions of the Construction Insurance Risk Engineers’ Group (CIREG) who produced a “Guidance Note on the Avoidance of Water Damage on Construction Sites” in February 2009. The pattern of water damage, and its relevance to high rise buildings, is also illustrated by the pattern of losses encountered on one of Europe’s largest construction projects. The section of the project providing low level facilities was relatively claims free; the section which incorporated high rise buildings presented the highest frequency of claims – all water damage – overshadowing the claims experience on the entire project. In the context of high rise buildings, there are two other major types of risk: wind related incidents in the exposed upper levels of these structures, and falls from a height, damaging other sections of the work below. The claims history discussed below deals with losses stemming from these risks. Materials In recent times, construction projects have increasingly used push-fit plastic fittings in pipework, rather than the conventional copper pipework, with compressed or capillary joints. A major source of burst water pipe incidents relate to plumbing sub-contractors’ failure to install the push-fit fittings properly. This is compounded by the fact that when a joint is incorrectly completed, on a plastic pipe, it tends to rupture apart completely, causing a major and sudden release of water. The older copper capillary joints tended to leak gradually, as a consequence of an inadequately welded joint. The main cause of these failures tends to relate to sub-contractors’ failure to push the poly-press fitting home fully, but occasionally, inadequate use of solvent material is the cause.


When a team of plumbing sub-contractors are adopting inappropriate working methods, whether by poor training or lack of attention to quality, a building can be riddled with multiple defective joints (1% of 200,000 joints in a major structure is sufficient to cause many losses). The difficulty is that the management do not know where the defects are, and these often only reveal themselves when a major burst of water occurs. A further problem, associated with plastic pipework, is that occasionally it cracks and ruptures - a problem rarely encountered on older copper pipework. In this respect, plastic, whilst easier to handle, carries a greater risk of water damage than conventional materials. Workmanship Associated with the problem of plastic pipework is the issue of defective workmanship. New plumbing systems require knowledge and experience of their use and installation technique. It is essential that proper training is given to contractors on any new material which is being used in the works. Moreover the main contractor needs to ensure that, in the appointment of skilled sub-contractors, they are complying with manufacturers’ instructions, installation standards and adherence to codes. It is feasible to incorporate compliance with these codes and to include written procedures in the contractual terms and then verify compliance in the form of site checks. It is well known that most incidents on a building site relate to human failure, rather than externally fortuitous incidents such as the weather. In high rise buildings the temptation for a contractor to take a short cut in arranging a temporary water supply rather than descending to ground level, is great. Too frequently, a contractor will attempt to use part of a water installation which may or may not be completed and ready for use. If that installation is not completed (with open joints and temporary stop offs), this commonly leads to incidents of water escape. A temporary water supply such as a hose attached to a tap left over-night can rupture during non-site working hours – during periods of higher water pressure, leading to easily avoidable water incidents. Design Whilst design of a building will always take into account the risk of fire and the prevention of it spreading, this risk consideration is rarely given in the case with water. Thus, incidents of water escape, at high level, can take the path of least resistance, via floor level, into a riser - causing extensive damage throughout the height of the building as the water descends into the basement. These types of claim which are often encountered near completion, when services are operational, and when the building is in its most fragile state, tend to produce the largest claims encountered by adjusters. Measures to avoid this include the installation of bunds to prevent escape of water into risers. Moreover, in a building design, combined service risers should be avoided with the separation between dry and wet risers, and the protection of sensitive electrical cabling and equipment. This applies to the risk of water travelling across the floor slab, where the design should arrange for cables, and other water sensitive equipment, to be mounted above the slab rather than laid directly onto the floor slab. The location of water tanks, and oil tanks at high level, should always be protected by perimeter bunds with proper drainage systems. They should be functioning before they are charged with liquid, to enable the short-term containment of leaks, and to permit the drainage of larger escapes of water in the event of overflow. High rise buildings have a particular vulnerability to materials falling from a height. In the present day environment, glass clad is favoured above more conventional materials, but


glass is especially susceptible to any type of liquid debris, such as concrete or other cement based construction material. In looking at this risk, underwriters need to consider the shape of the building, and its exposure at lower levels, to materials falling from a height at higher level. These are not normally contained to a single incident but multiple escapes which can affect all the cladding envelope of the building - leading to very expensive reinstatement and cleaning costs. Typical incidents include concrete dripping from skips carried by a tower crane which traverse across the cladding. More frequently, on high rise buildings, is the effect of wind which will force any recently laid liquid concrete through open voids onto the building’s exterior. Method Statement Associated with the risks outlined above, is the fact that modern construction techniques commonly require the fit-out works to commence at the basement of a building, whilst structural works are still underway at the top of the building. It is frequent for the activity above to interfere with the works below. Concrete spillage is one common instance, but the escape of other construction materials such as moulding oil for dismantlement of formwork can lead to contamination and damage to fragile elements of cladding below. Currently it is common to install lift cars in the main lift cores whilst the concrete lift cores themselves cannot be closed off to the weather elements. High rise buildings provide a particular risk to wind-driven rain entering the temporarily sealed core openings. Measures need to be taken to protect the sensitive components contained inside. 7.2 Loss Prevention / Mitigation measures The accident histories of tall building projects illustrates that the easiest way to reduce the overall cost of claims is by immediate loss mitigation techniques which are designed to respond promptly when a incident does occur. Looking at the largest losses of over £10m in the last 20 years, most of them relate to escape of water – when the escape of water has lasted over a far longer period than necessary. Had the project management prepared techniques to act quickly upon the occurrence of an incident, the severity of these loses could have been avoided. Thus, the National Westminster Bank incident in Princess Street in 1996, which was a burst water pipe producing a £20m claim was only this severe because a burst fire main was allowed to run from the time of the incident on Friday at midnight until the site team returned for work at 8.00 a.m. on Monday. In the HSBC Bank incident, a 12” fire main at the top of the building ruptured during a pressure test - leading to water descending all the way to the basement, and a £12m loss. This could largely have been avoided if the site team had known where to turn off the water immediately the rupture occurred, rather than 45 minutes later – by which time water had travelled to stories through a near-complete building, into the basement. Thus, the first step of project management is to ensure that staff is aware of procedures for action in the event of a water incident. This includes ensuring that the security personnel are aware of where to turn off water should a pipe burst occur. It also means that when pressure tests are being carried out, other personnel are on standby to act instantly if there is a pipe burst.


Project Management contact details should be given to staff and security personnel in the event of water escape during non-working hours and measures should be taken to ensure that the Emergency Services also have this information. Cost constraints these days have meant that many buildings approaching practical completion are not staffed by security personnel during non-working hours. This has been at great expense to underwriters when pipe bursts occur overnight. The site team arrive in the morning to discover extensively water damaged works. On some sites, the adjusters succeed in implementing recommendations for overnight security. This should include walking patrols so that water escape – the silent menace – can be detected and acted upon swiftly. Coupled with this, are the detection systems which can detect a fall in pressure and the possible existence of a leak. Such alarms should be audible alarms and naturally should be capable of being acted up when they do occur. A common theme on major losses is the failure of designated personnel to act when an alarm does go off. Check list of Prevention / Mitigation measures The counter-measures to prevent these types of incidents, which have been touched on in the sections above, can broadly be divided between ‘Prevention’ measures and ‘Mitigation’ measures:

Prevention Before works commence, the design team should be considering the following measures: Bunds for high level water and oil installations Division of risers – wet and dry Avoidance of laying cables directly onto floor slabs Clear identification of pipework and shut off points plus easy access Full functionality of drainage points in all water installations Sensitivity of building and suitability of plastic pipework Low pressure water alarms Location of water tanks Good claims histories have generally stemmed from projects where the employer takes control of risk management, as opposed to the principal contractor. Even if it is the principal contractor, a Comprehensive Risk Assessment should be carried out to fully consider the risk of water damage as well as the fire risk. The principal contractor should take responsibility for management of the water damage risk, rather than leaving it to separate trade contractors. The principal contractor’s responsibility should include setting up a Water Management Plan, setting out responsibilities and procedures in the event of an incident. Finally, the plan should consider the sequence of work and the method statements to ensure, not only the safety of personnel, but avoidance of fire, and equally important, the water risk. As defective workmanship is a common cause of burst water pipe incidents, systems should be developed for the appointment of properly trained plumbers with a certain level of competency. Finally, the workmanship itself should be subject to continuous supervision, inspection and certification. Recording of contractors working on different sections of the building enables a retrospective check if incidents occur due to a defective method statement encountered at a later date.


Mitigation The first step in mitigation is a procedure to allocate site responsibilities - for action

in the event of an incident. All personnel should be aware of emergency measures in the event of a water incident in the same way which a site protects against fire.

Consideration should be given to the use of security guards during non-working hours and walking patrols.

Alarm systems should be in place, in particularly water pressure detectors, which give audible warnings to personnel who are capable of reacting on an alarm.

The risk management team should be aware of incidents early on so immediate measures can be taken to prevent a recurrence.

Temporary water apparatus should be avoided in preference for the use of a permanent water supply. Temporary supplies should be closed off in non-working periods.

7.3 Claims and Loss Experiences Attrition Losses Due to appropriate design codes and working procedure severe losses are limited. Attrition losses are common especially damage by rainwater, broken water pipes // valves and activated sprinklers, fire in storage areas due to bad housekeeping (see picture)

Figure 22 - Miami FL, US: High-rise building, Storage area with an increase fire exposure due to bad housekeeping, material stored and the limited access (Source: Gero Stenzel)

Severe Losses Fire is one of the greatest risks when we are talking about high-rise buildings, Not only during construction, but also in operation. Main issue during construction due to the activities of a huge number of workers, especially at the end of the project (e.g. welding activities, smoking, no hot work permit), and the lack of comprehensive fire extinguishing measures (sprinkler, stand pipes, pumps) during this stage of the project.

Figure 23 - Beijing, China: Mandarin Oriental Hotel, Feb. 9, 2009 www.democraticunderground.com

http://www.democraticunderground.com/


Collapses These are a topic. But due to the design opportunities, the experiences learnt and the experiences of the past it has in the meantime more a theoretical character than it is a practical exposure scenario. High-rise buildings are also prestige projects with the consequence that the controlling procedures during design and construction are tough. A failure of the structure rarely happens in mature countries.

Figure 24 - Atlantic City, US: Collapse of a Parking Structure, Tropicana Casino and Resort, October 30, 2003 Source: http://failures.wikispaces.com But not only structures are exposed to collapse. More and more cranes are collapsing, mainly due to their age, lack of maintenance, inappropriate inspections etc.

Figure 25: New York, NY, US: Ground Zero Figure 26: Dubai, UAE: Flooding CPE / crane collapse exposure excavation Source: Gero Stenzel Source: http://uneasysilence.com

7.4 Fit-Out: Claims Issues It is increasingly common to see separate fit-out project policies on skyscrapers which are separate from the shell and core project policy. The fit-out project policy can be for $100m or more and it may be affected with Insurers who are different from shell and core CAR project policy. That fit-out policy is likely to cover both the fit-out works and liability

http://failures.wikispaces.com/


risk and cover will normally be in the names of all contractors involved on the fit-out, in any tier. Typical types of loss that can be encountered at the fit-out stage include: A defective plumbing fitting in the shell and core works ruptures during the fit-out,

causing damage to the fit-out works. The fit-out contractor can accidently cause damage to the shell and core works (e.g.

dislodging a sprinkler fitting) causing damage to both the fit-out and shell and core works.

The issue then is how do the respective policies respond? The fit-out insurers should meet the cost of repairs for damage to the fit-out works but they may then pursue a recovery against the relevant shell and core contractor. If that M&E (Mechanical and Electrical) contractor is the same as the M&E contractor working on the fit-out (despite the fact that there are two separate contract packages) the fit-out insurer may not be able to pursue a subrogated recovery against a co-insured under his policy (Petrofina v Magnaload). In the case of water damage incidents, it is not an uncommon cause to be in dispute – whether a pipe ruptured due to a defective coupling by the shell and core M&E contractor or whether it was dislodged by the fit-out contractor. The shell and core insurance cover may have ceased at practical completion - with the result that damage by an external cause (such as the action of a fit-out contractor) is not covered, but damage due to a latent construction defect would be covered under the maintenance extension. Where the fit-out contractor causes damage to the shell and core, that cost may have to be considered under the liability section of the fit-out policy. These issues need to be considered carefully, by Underwriters, if a decision is made to have separate insurers on the shell and core, and fit-out policies, since practical issues can arise in the handling of claims under each policy. A further practical issue which arises, when there are two policies running on the same building, is in connection with a major incident- for example a fire which destroys sections of cladding on the core works and also parts of the fit-out works. The fit-out contractor will want the shell and core contractor, and his insurers, to complete the cladding as quickly as possible so that their fit-out remedial works can commence. Any DSU covers on both policies will be further complicated by the fact that the fit-out works can often not commence until shell and core remedial works are substantially complete. Some developers overcome these potential difficulties by arranging insurance for the landlord’s fit-out and tenant’s fit-out works under the same project policy. The shell and core insurer would need to consider that, if he is not also insuring the fit-out works, the liability exposure under his policy increases in the event that defects in the shell and core cause damage to the fit-out areas. Similar considerations would apply to the fit-out insurer who can take on a substantial liability in respect of losses to the shell and core areas caused by fit-out.

London/Zürich, August 2012


References for Additional Reading

Publications: Wild, U. and Staub, K. (1993, Revision 5/1998). Fire protection on building sites in Construction/Erection All Risks insurance. Engineering, Swiss Reinsurance Co. Munich Reinsurance Company (2000). High-Rise Buildings. IMIA, WGP 40(2005). EAR/CAR – Third Party Liability – Existing and Surrounding Property. IMIA, WGP 28(2003). Risk Management approaches in CAR / EAR projects. The Insurance Institute of London (2003). Insurance of Revenue for Projects Under Construction. Cromwell Press Limited, Trowbridge, Wiltshire. Ascher, Kate (2011). The HEIGHTS: Anatomy of Skyscrapers. New York: The Penguin Press. Mapp, Keith. A consistent method of calculation of Probable Maximum Loss for buildings under construction or undergoing refurbishment. Codes: National Fire Protection Association (2009 Ed.) NFPA 5000 – Building Construction & Safety Code. National Fire Protection Association (2010 Ed.) NFPA 10 – Standard for Portable Fire Extinguishers National Fire Protection Association (2010 Ed.) NFPA 13 – Standard for the Installation of Sprinkler Systems. National Fire Protection Association (NFPA 14) – Standard for the Installation of Standpipes and Hose Systems National Fire Protection Association (2011 Ed.) NFPA 70 – National Electric Code National Fire Protection Association (2011 Ed.) NFPA 72 – National Fire Alarm and Signaling Code National Fire Protection Association (2010 Ed.) NFPA 110 – Standard for Emergency and Standby Power Systems American Society of Mechanical Engineers (2010). ASME A17.1-2010 Safety Code for Elevators and Escalators. Construction Confederation, Fire Protection Association (2009, May) Fire Prevention on Construction Sites – The Joint Code of Practice on the Protection from Fire of Construction Sites and Buildings Undergoing Renovation (7TH Ed.).

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