No. 8 Chifley Square, SydneyPrioritising building design and energy savings

1 / 7November 2013

Owners - Mirvac Group and Keppel REIT.

Architects - Rogers Stirk Harbour + Partners and

Lippmann Associates.

Builder - Mirvac Constructions.

Facade Contractor - Arup.

Structural & Civil Engineers - Enstrust.

Facade Consultant - Permasteelisa Pty Ltd.

Ratings

- 5 Star Nabers Energy.

- 6 Star Green Star Office Design v2.

Awards

- 6-Star Green Star Office Design v2.

8 Chifley Square invigorates a dark city

hub with startling architecture, innovative

working spaces and generous community

open spaces.

The building was completed ahead of schedule

in August 2013 with 42% of its office floor

space leased. The 34 storey building resembles

a giant glass obelisk standing guard over the

steel cut-out statue of Ben Chifley; for which

the precinct bears his name; a Labour leader

who became the 16th Prime Minister of

Australia from 1945 until 1949.

Enclosed by three prominent city streets

Elizabeth, Phillip and Hunter Streets, the new

building is a proud landmark, that heralds a

creative resurgence to a neglected part of

Sydney’s CBD. The building’s strong architectural

design, features a cube shaped skeletal brace,

vibrant red in colouring, it flows vertically, like

a main artery providing an essential life source

through the building’s perphery.

“Mirvac...wanted to make it a flagship development for good corporate citizenship.”

Ed Lippmann speaking about Mirvac Projects, Principal Architect - Lippmann Partnership

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3. 5-Star NABERS Energy and 6-Star Green Star ratingsrelying on a tri-generation plant, blackwater treatmentplant, chilled beam ceilings to reduce the carbon footprint to 70% for a typical building of this size.”

High achieving architecture.

To achieve the first two outcomes, the architects tackled the overall structural design for the site to achieve a lighter more open appearance. The concept included a high unobstructed podium, to obtain the illusion of extending the reflected open spaces of Chifley Square and increase the level for daylight penetration on the first office level. The open space would also encourage more community traffic through the precinct, an activity proven to be lacking in this vicinty in the past. The five level podium with cafe and recreational public space was designed to keep within the steel bracing on the building. Interspersed are 1500 mm high glass walls that provide protection from wind and noise, and give some privacy to cafe goers. The public area sits high enough to overlook the non vehicular Chifley Square and complements the welcoming passage into the light filled office environment.

On every level, to save floor space and maximise light, the architects placed all building amenities at the rear, on the southern side, allowing the northern orientation of the building to contribute further to it’s lighter appearance. The structural engineering design was based on four concrete mega columns situated on the extremities, supporting the

8 Chifley Square replaces the severe “Chicago School” Goodsell Tower construction. With its predominantly charcoal steel structure, small vertical aperatures and claw like entrance, little light penetrated the interior. The building represented draconian working conditions within uninspiring architecture.

It’s successor is a welcome contrast to the ugly, inadequate 1970’s building. Dwarfed in it’s surroundings, the tower stood at 84 metres high and with only

18 storeys of office accommodation, it was time to demolsh the old and revive with the new.

The site was purchased in 2006 by a joint venture, Mirvac and Australian Retirement Fund (ARF) for $60.2 million. The NSW State Governmnet held tenancy of the building until 2008.

Setting higher benchmarks

In 2006, the internationally acclaimed architectural practises Rogers Stirk Harbour + Partners, and the Australian based company, Lippmann Partners won the City of Sydney Design Excellence competition for 8 Chifley Square. The brief criteria, setting higherbenchmarks, stimpulated 3 main building objectives. “1. An extension of the existing Chifley Square ground plane as a dynamic public open space.2. Provision of a series of office “village” environments where varying floor plates and 3/4 storey voids, offer unique workspaces and flexibility within a commercial tower.

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“This is an

outstanding medium-

term redevelopment

opportunity, being

loated in the

heart of the CBD

financial district

and adjacent to a

number of Sydney’s

best premium grade

buildings...”

Nick Collishaw -Previous Managing Director, Mirvac.

“The open space is

repeated midway up

the building and at

the top, integrating

Australia’s outdoor

lifestyle into the city

environment”

Ed Lippmann -Managing Director, Lippmann Associates.

Above left: Goodsell Tower, an outdated building with outdated functionality. Above top: Model of 8 Chifley Square concept with insert - mid level recreational space.

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bracing (sway frame), and horizontal steel structure of the building. Four columns centrally placed create the internal layout plan. Their load bearing is transferred via the inclined beams on the recreational levels to the external columns. This engineering feat enabled the columns throughout the building to remain at the same diameter internally, offering greater flexiblilty for office layouts on all floors. Daylight was then essentally unemcumbered, creating an appealing, light filled working environment.

Derived from following thesuccessful trend to encouragegreater employee interaction within working spaces, the architects composed a unique office concept, the “Vertical Village”. Single corporate tenants, could lease two or three connected levels ranging from 1,800 to 2,400 square metres. Internal interjecting glass staircases combine the levels and frameless glass balustrades surround the open cut perimeters, giving the occupants uninteruppted multi-level views. The abundant use of glass, extending the northern light.

Midway, on the eighteenth floor and nearing the top of the structure, the thirtieth, large open space recreational areas were incorporated. Their wide verandahs and green apects would provide relief from the normal working environment for employees and entice outside visitors with exceptional views.

Contributing further to the light appearance of the architecture, the facade is clad with large double glazed windows, accented with minimal framing.

In June 2011, excavation began onsite. A tight construction site with logistical accessibility issues, would hamper strict deadlines and increase costs, so much of the building infrastructure was manufactured and assembled off site.

Solar control challenges The building’s orientation had virtually unobstructed solar access and to maintain the facade’s light appearance and the views from within, the architects opted for an “external curtain wall shading system” and commissioned facade specialists to design and manufacture a “brise soleil” on the building’s northern and western facades. This perimeter of steel louvred panels, cantilevered beneath the glazing, provided a safe area for maintenance crews and aided in shading the northern interior effectively only during the months of October to February. Further internal shading would be required to reduce the solar gain impact and alleviate the solar glare irritation, an assured occurrence for the tenants in the building.

Opportunity knocksJason Turner from Turner Bros. having just completed his involvement with No. 1 Bligh Street contacted Guy Bell, Mirvac’s Senoir Buiding Engineer. Having seen the results at Bligh Street, Guy and others from Mirvac were impressed with the results and invited

“The design,

whilst internationally

significant, is very

specific to the climate

and culture of Sysney.

The result is a beautiful

piece of architecture

that enhances the

public realm while

providing occupants

with wonderful internal

spaces within which

to develop working

communities.”

Ivan Harbour -Rogers Stirk Harbour + Partners.

Top left: Typical floor plan showing 4 central columns.

Left: Artist impressions of the “Vertical Village” concept.

Above: Onsite construction and hauling a section of sway frame into place.

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Turner Bros. to specify and tender for the project. The architects’ solar control product choice was roller blinds for their light and potentially transclucent appearance. After a series of meetings, Jason organised prototype installations of metallic and non metallic “Screen Nature” fabric blinds at Mirvac’s project office.

Similar to Bligh Street, the complexities of solar control and operation on this project demanded a flexible, integrated and upgradable operating system which was equally essential to delivering both the building’s and potential temants’ requirements.

To achieve the best outcome, Turner Bros involved the engineering team at Horiso. Successfully manufacturing for project specific outcomes, their highly advanced Climate Ready® Operating Systems were favored for the project. Turner Bros. tendered, won the contract and completed all details of the project in just 18 months.

The contract entailed the manufacture and installation of 1,458 linked roller blinds to effectively manage solar gain and glare and 44 blockout linked roller blinds on levels 17 and 18 to fulfill a tenants’ meeting and boardroom requirements. Overall, the operating system maximised benefits and reduced the impact

of solar variances, while the operating system’s integration allowed communication with the tenant’s sophisticated audio visual system.

The right choices The fabric component for the majority of the roller blinds has properties with high performance solar control factors, up to 94% of light rays are filtered. It is 100% fibreglass, non combustible, has a 3% openness factor and is PVC free with a halogen free coating making it highly suitable, and a contributing factor to the green building accreditation. The innovative blind installation, combined with the fabric’s fine basket-weave appearance produced the design outcome, to look light on the large glazed areas, particularly, on the 7 “Vertical Village” levels.

The Climate Ready® Operating System incorporated 346 EB2 series controllers and 681 motors, individually controlling 2 blinds. EB2 D controllers were used throughout the main floors from levels 6 - 30, with one dynamic brightness sensor installed

on the rooftop. Horiso measured the surrounding buildings’ overshadowing and input from solar path calculus determined the accurate times for the roller blinds to operate in accordance with the results. Horiso determined the glare zones on each “Vertical Village” and using Facade Intelligence Modeling (FIM 3D modelling), the blinds operate, providing a comfortably lit atmosphere for the break out areas without compromising solar gain or glare in the office areas beyond. 2 Control Points with R232 interface for audio visual integration were installed specifically for the meeting and boardrooms.

“It was one of our

most successful

outcomes, working

alongside Mirvac, the

architects, facade

engineers and Turner

Bros. The overall

project’s solar control

and operating systems’

manufacturing,

electrical installation

and commissioning

stages were

completed without

any communication

problems or delays.”Neil Krotzsch - Engineering Manager, Horiso.

Diagram above: Horiso’s analysis of overshadowing perspectives.

Below: The north facing elevation with highlighted glass boxes.

Success is not worthy without overcoming challenges!Although this was the first time on a major project that Turner Bros. and Horiso successfully understook the electrical, solar shading manufacture, installation and commissioning of the solar control and operating systems, it wasn’t achieved without overcoming two main obstacles.

Namely, the invisible installation of the electrical cabling component of the operation system and blind head boxes on all 7 “Vertical Villages” and on levels 18 and 30, the open recreational areas of the building.

The “Vertical Villages” with their 2 and 3 floor heights required two or three individual roller shades for each drop, motors and electrical cabling for the blinds operating system. No bulkhead and no cavity, meant the usual installation method was not feasible. Turner Bros. installers and Horiso engineers realised to combine the three elements in the one area was the only plausible means of ensuring invisibility.

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Blind headbox

Blind drop

H wind beam

Side elevation

Electricalcabling

H wind beam

Blindheadbox

Blind drop

Electical cabling

Isometric view

The horizontal 400 x 150 mm H shaped structural steel wind beams provided the ideal space to fit in the blind headbox and into which the cables could be hidden above. Horiso manufactured the custom headboxes, the blind hardware was inserted and specifically designed “fingers” held the electrical cables securely on top of the headboxs.

On levels 18 and 30, finding a solution was to prove more complicated. These spaces included free standing steel framed glass boxes, setback from the perimeter of the facade and housing the cafe.

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Key building facts

• Cost AUS $154.4 million • Column free structure• Exposed stairwells• 34 storeys / 21 office floors• Site area 1,580 square metres

• 5 storey foyer open space

• 7 “Vertical Village” areas

• Core height - 141 metres

• Approximately 19,360 square metres office area

• 2 landscaped sky gardens

• 130 bicycle bays

• 32 car spaces

• Showers & change rooms to encourage physical activity; such using bike transport; to and from work

• Steel roof Infrastructure to support photovoltaic panels once the technology becoming commercially viable for a building of this size.

8 Chifley Square’s Environmentally Sustainable Design achievements

• Brise Soleil on north and western facades.

• Over 1400 roller blind reducing energy costs

• Roof mounted tri-generation plant - waste heat from electricity production to reduce building’s grid power demand.

• Black water treatment plant processes up to 20,000 litres of waste per day with reuse for toilets and gardens.

• 70% carbon footprint reduction when compared with similar sized conventional office building towers.

• Sub floor chilled air conditioning.

• Building waste recycled.

The content of this case study was derived from sources which Horiso believes to be true at time of publication.

8 Chifley Square

“another example

of how through our

integrated approach,

we can deliver positive

results for our tenants,

investors and also for

the environment in

which we operate.”

Nick Collishaw -Previous Managing Director, Mirvac.

Glass walls, floor and ceiling; with the exception of a concrete ceiling on level 30; into which the same blind and electrical components needed to be installed.

Adding to this, after considering the blinds’ sheer height, Turner Bros. foresaw a blind alignment issue during operation which may have caused serious damage to the blind and operating system if not addressed prior to installation.

Turner Bros. fixed brackets for the blind installations into the existing

top beams, incorporated side cable guides which ran down the glazing unobstrucively and terminated these into the steel footings.

The finishing touch Skyward angled LED strobe lighting, installed on the sway frame, exterior fire stairwell and on the soffit (open) levels, light up at night fall, dramatically accentuating the glass features of the building, substituting the use of conventional interior lighting. The visible impact completes the uniqueness of Sydneys’ latest stand out commercial enterprises.

Opposite page top: Plan shows positioning of the motors, cable guides. Opposite page left: Illustration depicts blind and cable installation within H beam. Opposite page right - top: Artist impression showing height of glazing in “Vertical Village” spaces.Below: Lit bracing and stairwell adds further impact to 8 Chifley Square.

This page right: The strong red bracing emphasises the height during the day while adding to the construction light appearance.

www.horiso.com.au

Some images & content references: Rogers Stirk Harbour + Partners Lippmann Associates Architecture & Design Mirvac Design Illumni Sydney Morning Herald The Fifth Estate The Urban Developer Entrust IndesignLive.