Valer daniel rudics green roofs dissertation_project

How can green roofs

influence the urban

environment?

Dissertation for 7th semester Bachelor

in Architectural Technology and

Construction Management

Student: Valer Daniel Rudics

Consultant: Mihoko Goto Brethvad

VIA University College, Aarhus, Denmark

Hand-in date: October 2013

Valer Daniel Rudics Green Roofs - 7th

sem.

October 2013 Dissertation project

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TITLE SHEET

TITLE OF THE REPORT: How can green roofs influence the

urban environment?

SUPERVISOR: Mihoko Goto Brethvad

AUTHOR: ____Valer Daniel Rudics____

DATE/SIGNATURE: ____25/10/ 2013______

STUDENT IDENTITY NUMBER: 178744

NUMBER OF COPIES: 1 (one in pdf format)

NUMBER OF PAGES (2400 characters per page): 27 pages

GENERAL INFORMATION:

All rights reserved – no part of this publication may be reproduced without the prior

permission of the author.

NOTE: This report was compiled as part of the

Constructing Architect education – every responsibility

concerning guidance, instructions or conclusions is

hereby renounced.


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1. Preface / Acknowledgements

This report is the last of its kind in the Architectural Technology and Construction

Management education. The dissertation report consists of 1/3 of the ECTS points accredited

for this semester from a total of 30 ECTS and it should convey to which degree I can

complete a problem based dissertation of my own choice and it should give a further

familiarity to a restricted topic within the education. Furthermore, the dissertation should

document my ability to communicate in writing.

The purpose of this report is to write about green roofs, but since this theme has

become more and more familiar nowadays, I have decided to focus on a certain area and

analyze how the urban environment can be influenced by this technology.

The research of the report is based on written literature related to green roofs as well as

websites, on-line videos and internet articles, and interviews with several professionals from

the green roof industry.

I would like to thank the people who supported me in the realization of this report.

Many thanks to my guiding teacher, Mihoko Goto Brethvad who accepted the problem

statement and the role to supervise my working process, as well many thanks to Ulrich Reeh

and Gregers S. Gregersen from VegTech A/S, Lise Mansfeldt Faurbjerg from Henning

Larsen Architects A/S, Anja Pelle and Torben Hoffmann from BygGros A/S, Søren Nielsen

from DanJord A/S, my guiding teacher for the bachelor project Henrik Windbirk, and all my

colleagues and friends who supported me in writing this report.


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2. Abstract

The problem statement for the dissertation is ‘how can green roofs influence the

urban environment’. The theory is based on analyses related to the green roof technology

and how could green roofs make the urban life a more sustainable, a more habitable and a

more pleasant environment to live in. The analyses focus on several points that bring out the

impacts urban life is combating with at the moment and the aim is to find out how the

problems can be remediated.

There are many analyses that argument about green roofs having a positive impact upon the

urban environment. And even though the technology is rather new, green roofs projects are

increasingly implemented nowadays. In order to find more about those impacts and their

solutions you are invited to read about them in the following pages.

After the introduction where the basic information about green roofs is presented, the report

will continue with analyses and conclusions covering subjects such as: storm water

management, heat island effect, urban environment, green architecture and solutions, nature

reintegration, urban sustainability, storm water runoff, energy saving, and some more facts

related to green roof implementation in urban environments.


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Table of contents

1. Preface / Acknowledgements ................................................................................................. 2

2. Abstract .................................................................................................................................. 3

3. Introduction with problem statement ..................................................................................... 5

3.1. Background information and presentation. ..................................................................... 5

3.2. Rationalization of choice of subject and profession relevance. ...................................... 5

3.3. Problem formulation questions. ...................................................................................... 5

3.4. What is a green roof? ...................................................................................................... 6

3.5. How are green roofs made? ............................................................................................ 7

4. Main section ......................................................................................................................... 10

5. Conclusion ........................................................................................................................... 29

6. List of illustrations ............................................................................................................... 32

7. List of references: ................................................................................................................ 34

8. List of enclosures ................................................................................................................. 38


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3. Introduction with problem statement

3.1. Background information and presentation.

The dissertation is part of the 7th

semester Bachelor in Architectural Technology and

Construction Management programme at VIA UC Aarhus. In this report I will analyze and

research information about green roofs and try to explain ‘how can green roofs influence the

urban environment’ and how to improve the living conditions in this area.

3.2. Rationalization of choice of subject and profession relevance.

Nowadays 'sustainability' has become a big-time trending in the design world, it is a

word that anoints all it touches with an air of innovation and freshness. Yet, what

sustainability truly aspires for is independence from such trends, aiming rather for longevity

and the promise of a healthy and dependable environment well into the future.

In the era of modern architecture the urban environment is becoming more and more

artificial in terms of living space. The green spaces are replaced with boxes made of concrete

and steel and as a result the environment is engaged in the famous duel of ‘David and

Goliath’ where only the strongest survives.

There are many environmental problems the urban environment encounters with because of

the modern architecture, and as a result city dwellers have started to take initiatives in order

to face this great challenge. Some of the problems urban environment is facing are heavy rain

falls and storm water management, the heat island effect, surplus of CO2, lack of green areas

and animal habitat, lack of biodiversity, etc.

Green roof technology is one of the most common methods of reintroducing nature back into

the living urban space. During this report I will search for information and data regarding the

problems the urban environment faces and I will analyze and debate how can green roofs

influence this situation.

3.3. Problem formulation questions.

In order to answer the problem statement ‘How can green roof influence the urban

environment?’ I have formulated several research questions:

What is a green roof?

How are green roofs made?


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What are the advantages and disadvantages of building a green roof?

What are the problems the urban environment faces nowadays?

3.4. What is a green roof?

A green roof, also called eco-roof is an engineered vegetative roof cover with plants

and growing medium or engineered soil, taking the place of regular concrete, tile, or shingle

roof. The most important aspect is that they are living breathing roofs planted with many

types of vegetation that use the foliage of plants in order to protect the building.

Green roofs have been around in various

forms since the ‘Hanging gardens of Babylon’

thorough Scandinavian homes, thorough the

elaborate Rockefeller Center roof gardens built in

the 1930’s (Figure 2). But since 1960’s Germany

has been the birthplace for modern day green roof

technology, where the engineered systems have

been tested and developed.

Green roofs are a form of low impact development that help reduce the negative

effects of a building’s footprint by recreating the lost green area at the roof level.

Because of their thermal behavior under the solar radiation, green roofs are used in

warm climates but they are also used in northern climates to improve the insulation

performance of the building environment. They have several positive effects in the urban

environment with the most significant being their ability to retain and detain storm water,

mitigate the urban heat island effect, improving of outdoor air quality, noise reduction,

reduce the building energy consumption by cooling the roof in the hot season and also create

habitat for animals and plants thus improving urban biodiversity.

In terms of design there are two main classifications of green roofs: extensive and

intensive. Extensive green roofs have a thin substrate layer with low level planting, usually

sedum or lawn, and can have a lightweight structure. Sedum is suitable and very common for

using on extensive green roofs. They are succulents and they store water in their leaves,

allowing them to be drought resistant, simply turning red/brown when they dry out. Extensive

green roofs are very popular in Europe (“In Germany more than eighty percent of green roofs

Figure 2


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are extensive” – Snodgrass 2010, p.22). They are simpler and thinner in profile as well as

less expensive compared to the other category. The medium depth of an extensive green roof

can vary from 2,5-15cm and they can be installed on slopes up to 30o.

Intensive green roofs generally assimilated to conventional roof gardens, have a deeper

substrate layer to allow deeper rooting and more organic growing medium capable of

supporting a large variety of plants, sometimes also trees and shrubs. Intensive roofs are

generally open for regular use and sometimes serve as amenities for the inhabitants of the

building. Medium depth on an intensive roof can go up to 1m or even deeper for more

intensively managed roof gardens.

Research into the field of environmental psychology has shown that people have a

more positive response to areas with vegetation and natural elements than those without.

People tend to prefer urban green environments and they find them more beautiful, but

having plants on a roof requires water to live and prosper. And because the function of any

roof, green or conventional, is to keep water out of the building, some people find it tough to

get their minds around.

Re-designing the rooftop as a space for plants opens up attractive possibilities. If you

have the possibility to grow plants up there, why settle for modest succulents when you can

restore some native flora, offer wildlife habitat, harvest fruits and vegetables, or walk

barefoot through the grass?

3.5. How are green roofs made?

Depending on the type and/or weather conditions, green roofs are built with different

layers and variable thicknesses. The standard layers of a green roof system, from bottom to

top generally consists of a root barrier, drainage, filter, growing medium, and vegetation

layer. In roofing language, the whole roof construction above the waterproofing membrane is

known as the overburden. The most basic green parts of a green roof are the growing medium

and plants. The roof deck and the waterproof membrane together, ensure the structural

integrity of the building. Any roofing system should have some kind of drainage layer in

addition to the primary and secondary overflow drains, and other layers can vary.

The root barrier is the first layer above the buildings’ roof and its purpose is to provide a

waterproof membrane to the assembly. One of the most important objectives of any green

roof system design is leak prevention and in case it occurs, then all the layers need to be


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removed to locate it. As the name suggest, another purpose of the root barrier is to protect the

roofing system from plant roots that seek for water and nutrients for the plant. Roots grow

and move through soil and they could penetrate the assembly from the upper layers.

The drainage layer which in most cases has a water retention capacity; is important to provide

an empty cavity between the layers in order to allow the excess water to move freely out of

the roof. This role reduces the risk of water leaking in the assembly. To be considered that

water adds an extra weight to the roofing system and therefore to maintain the structural

capacity of the assembly it is important to ensure a good drainage. An efficient drainage also

prevents plants from growing and damaging the root barrier and the roofing assembly from

excess water that can be accumulated in the membrane. The main objective of the water

retention layer is to control water runoff and keep the medium layer moist. Since the

extensive green roofs have a small thickness of growing medium and vegetation they require

less water holding capacity compared to intensive green roofs which have a bigger growing

medium and vegetation with stronger roots that require more water and nutrients in order to

survive and bloom.

No matter the type of the green roof system, the purpose of the filter is to prevent water

runoff together with the particles from the upper layers and block the drainage layer. The

filter prevents fine materials from infiltrating into the lower layers during the drainage

process as well as maintains the integrity of the growing medium and the vegetation.

The growing medium layer supplies nutrients and water for the plants’ biological functions

and it also contributes to thermal performance and water retention. Moreover, the growing

medium is a space provider for plant roots to settle and strengthen, to be able to withstand

rough weather conditions and wind forces on the roof tops. The age and the content of the

medium are important to be considered because they directly affect the performance of the

layer. The content of the growing medium is kept confidential by manufactures and may vary

depending on the type of chosen vegetation. All plants need organic matter to grow and

prosper, but some need more than others. For example, larger plants such as small trees and

shrubs require more nutrients present in the growing medium compared to smaller plants, like

sedum. Sedum is a very reliable genre of plant that has great endurance for drought. Many

species can tolerate up to 1 month without precipitation and some species can endure up to 4

months.


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The aesthetic layer of a green roof, and possibly the symbol that categorizes a green roof as

an environmental friendly product is the vegetation layer.

As mentioned previously, the thickness of the growth

medium can vary depending on the layer structure. Figure

3 represents an example of extensive green roof with

minimum dimensions. This type of medium is most

common used; it is called sedum and it can be placed on

roofs with a slope up to 10o and roofs that can take low

dead loads. For this example the used layers are: 30mm of

sedum mat, 150g of filter cloth, 25mm of drain plate,

waterproof and root-resistant membrane, and root barrier foil.1

Some of the advantages are: lightweight construction, easy installation, uniform expression,

minimal annual maintenance (1-2 times/year), and a 25 year product warranty.

By using this type of green roof with a thickness of approximately 55mm, there is an

estimated 50% rain water retention per annum, with ca. 15 ltr./m2. When saturated the

assembly weights approximately 50kg/m2.

Since the vegetation consists of extreme drought tolerant herbs which can also thrive under

harsh conditions in their natural environment, they have a high capacity of regeneration and

require minimal care. The selected sedum typically takes 2-3 seasons before it covers the roof

surface completely. The main flowering system is from

April to July, but having also other flowers the

blooming season can be extended. In the flowering

season the sedum grows 7-9 different species of herbs

and grasses with varying colors like white, yellow,

pink, red to blue, but also outside the season the roof

offers a great sight, such as the one on the roof of ‘8

Tallet’ in Copenhagen, Denmark (Figure 4).

Depending on the layer structure, in Denmark are also used other types of extensive green

roof that can vary from 50 to 150mm in thickness and what is above it is considered an

intensive roof.

1 Byg-gros A/S - http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/sedumtag-50

Figure 3

Figure 4

http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/sedumtag-50


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One of the thickest intensive green roofs can be up

to 1200mm (Figure 5), which are considered like

rooftop gardens. In most cases they are located at

ground level because of the high load capacity they

have (750-1200kg per m2). This type of roof can

be implemented on top of underground parkings.

Some of the advantages are: retention of water

approximately 90%, drainage and water reservoir

plate can hold up to 29 liter of water per m2,

covers and protects the building, fast and easy installation, ability to bring gardening to the

buildings below ground, etc. Having a deeper medium, there are more possibilities for plants

to be grown, varying from grasses, herbs to shrubs and threes.2

Nowadays a lot of literature babbles about how delightful and environmentally

friendly green roofs are. But the fact that sustainable design can save the planet as well as the

troubled economy is not enough. It will actually need much more to bring about the

implementation of green roof technology and other correlative sustainable building methods.

It will require a straightforward debate of the challenges, commitment, and also costs

involved as well as the paybacks. Research will be necessary to be made in the constructions

and the sometimes difficult maintenance work in order to evaluate what works and what does

not.

4. Main section

In Europe, green roof systems have been shown to provide many ecosystem services

for more than three decades. Much of green roof research and product development took

place in Germany, Switzerland, and Scandinavia, and articles were written in in languages

other than English. One of the most well-known set of guidelines for green roofs throughout

Europe is the FLL Guidelines (Forschungsgesellschaft Landschaftsentwicklung

Landschaftsbau [the German Landscape Research, Development and Construction Society]).

They are formally known as the Guidelines for the Planning, Execution and Upkeep of Green

Roof Sites, and are used for green roof design, specification, maintenance, and testing. The

2 Byg-gross A/S - http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/diadem-1200

Figure 5

http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/diadem-1200


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FLL guidelines correspond to findings from empirical green roof research and application

throughout Germany (Dvorak 2010, p.198).

In Denmark for example, some professionals say that they do not follow the FLL Guidelines.

Anja Pelle from BygGross A/S says “we do not use FLL Guidelines because their German

empirical research does not fit to ours”3. It is most likely that each country should have its

own guidelines because of the different climate conditions, and other approaches towards

green roof industry.

It is easier said than done to make generalizations about green roofs because the

benefits provided on a particular case depend on many variables and can be different from

one another. For example the climate conditions in North America are much more diverse

and there are few standards for design details and materials compared to Western Europe.

Most projects are not monitored, as a result data are insufficient and expectations for

performance are problematic. On the other hand green roofs are well documented in Europe.

Most often they are built for other reasons than aesthetics, after all even the most basic

extensive green roof offers a better look than its asphalt- or clad- conventional counterparts.

Research is in early stages, but studies advocate that the most significant energy

impact is the reduction of heat flow into buildings during the summer season, and also the

need for air conditioning, thus resulting in lower annual energy costs. Some studies also

present lower winter heating costs during the coldest months.

Weather conditions and the way the building is functioning, as well as specifics of the roof

construction are some of the factors that will directly impact the actual savings of a green

roof. But building characteristics together with roof –to – wall ratio is another significant

factor. To be considered that the bigger the ratio the bigger the impact of the green roof is

likely to be, although the impact of the roof in taller buildings is most significant on the top

floor.

Due to their environmental benefits, green roofs became more and more popular over time

and nevertheless, their biggest disadvantage remains the cost. In most cases, green roofs

experts agree that some of the reasons for high green roof costs are because of the materials

that need to be lifted with cranes to the roof tops, high insurance premiums, and also the

3 External lecture from BygGros A/S with Anja Pelle at VIAUC Aarhus – September 2013


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expensive labor cost. Besides that, green roofs add more weight to the roof, which leads to

changes in the structural system, increasing the structural costs.

While a green roof can be designed to maximize some benefits of the building, that

improved performance might come with the cost of another or make the project more

miscellaneous and overpriced. Some individual projects will provide the building owners

and its users benefits such as energy savings, but in order to reduce the impact of the urban

heat island effect, if will require a large scale implementation of green roofs. However, in

some cases the energy savings alone perhaps will not justify the implementation of a green

roof, but they are on the list of benefits that makes green roofs alluring as sustainable design

tools. Keeping that in mind, it is becoming clearer that green roofs can be good tools to

achieve many sustainable purposes. Green roofs built on a large scale in urban areas, show

some potential for meaningful energy saving and other environmental retributions as well as

a less perceptible development in the quality of urban life.

During the hot season, urban environments have higher temperatures compared to

suburban and rural areas because of their congregated buildings and paved surfaces that

retain heat during the day and slowly release solar radiation during the night. This

phenomenon is not only a matter of comfort but also of public health and in the past ten years

it has become more and more difficult to combat with it.

Statistics have shown that one of the

main causes of natural hazard

mortality, mainly among elderly and ill

people is extreme heat, in the urban

environment also known as the urban

heat island effect (Figure 6). This

phenomenon is the reason why urban

areas have higher temperatures than

suburban and rural, and it is caused mainly because of the dark colors of building’s roof tops

that absorb energy from the sun. In 2003 over 70.000 people have died because of the heat

wave that stuck Europe and only in Paris alone over 19.000 people4. Because the lack of

vegetation to cool down the surrounding environment, urban areas deal with the heat waves

by using air conditioning. This method not only contributes to energy use increases in

4 Insolation (heat wave) - http://www.youtube.com/watch?v=xRD8maZuXr4

Figure 6

http://www.youtube.com/watch?v=xRD8maZuXr4


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residences but in fact air conditioning consumes more electricity than any other household

appliance.

Some of the causes of urban heat island effect are absorption of short-wave radiation from the

sun in low reflective materials and trapping them by multiple reflections between buildings

and street surface, air pollution that absorbs and re-emits long-wave radiation to the urban

environment, increased heat storage by building materials with large thermal admittance,

turbulence heat transport from within streets that is decreased by reduction of wind speed,

etc.

In the last 30 years the land development has rapidly increased in suburban and urban

areas, as well as the water runoff, among other. The explanation is that, before land is

developed, the runoff and stormwater are accommodated by natural systems. Some examples

are leaves and undisturbed soil that absorb rain, recharge groundwater levels and sustain plant

life; and rough and uneven topography that slow the flow of water running over its surface

into rivers and bigger water collecting bodies. But because of increases in pavement,

buildings and other water-resistant surfaces, runoff volumes have increased dramatically, and

managing it has become a state of urgency.

Most water treatment systems were not built to withstand the high volumes of water

cities face nowadays and most traditional control measures do not work very well. In some

cases stormwater runoff can overload the water treating systems. Because some systems treat

sanitary sewage from showers and toilets together with stormwater in the same facility,

during a rainstorm the water coming in can exceed the system’s capacity, thus resulting in

discharges of mixed sewage and stormwater directly into rivers, lakes, and streams. In the

United States, these combined sewer overflows (also called CSO) discharge 3.2 trillion liters

of untreated sewage and stormwater every year (U.S. Environmental Protection Agency

[EPA] 2004a)5. CSO’s can contaminate drinking water supplies, waterfront parks and

beaches, seafood stocks, threatening public health and environmental quality.

Unfortunately, separate sanitary and stormwater sewers will not magically solve water

pollution problems; there are also other factors that influence it. When it rains, water running

off from conventional roofs and paved areas collect and carry pollutants to rivers, lakes, and

other water bodies. Those pollutants can include fertilizers, herbicides, and insecticides from

5 U.S. Environemental Protection Agency - http://water.epa.gov/aboutow/owm/upload/Water-Reuse-Guidelines-

625r04108.pdf

http://water.epa.gov/aboutow/owm/upload/Water-Reuse-Guidelines-625r04108.pdf



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farms and residential developments; oil and grease from roads and energy production

facilities; sediment from construction sites; etc. In the United States alone, more than 38

trillion liters of this untreated runoff flow in the receiving waters every year (EPA 2004a).

The result of this contamination is a danger to aquatic life by reducing the diversity of insect

and fish population; it can also make water unsafe for humans, because of unsafe levels of

bacteria from stormwater runoff. In addition, stormwater runoff during the hot season months

contributes to higher temperatures in rivers and streams (from 3 to 7oC) potentially

compromising the health of temperature-sensitive aquatic species [EPA 2004b].

Green roofs can be part of a more effective approach in terms of stormwater

management. In Europe and North America it is the benefit that has been most amply

documented and validated by research.

Stormwater runoff can be minimized in the case of green roofs during storms, and even

during the worst storm, there will almost always be less runoff compared to a conventional

roof. The advantage of a green roof is that not only the assembly can retain water but it also

allows water to run off more slowly and over a longer time frame, thus reducing the intense

peak flows during storms. In addition, the water used by green roof plants never runs off, but

evaporates back into the atmosphere. This process is called evapotranspiration and it is

explained as evaporation of water from the green roof assembly and release of moisture from

the plants. Vegetation in open areas use sun energy to control the ambient temperature by

releasing vapor intro the air and also contributing to the water cycle, however in urban areas

there is not enough vegetation to cool down the environment thus leading to temperature

increases.

In Scandinavian countries where there are a lot of precipitations, such as Denmark, specialists

say that green roofs are seen as a benefit due to their water retaining properties to combat

frequent rain falls and heavy storms. In a publication from a Danish tabloid magazine

‘Licitationen’, ARK BYG declared that for all new flat roofs with a slope of less than 30

percent, it is strongly encouraged to implement a green roof construction. If old roof have to

be retrofitted, the building owners may be able to receive public financial support for a green

roof. In Switzerland, the cities of Baser, Zürich, and Lucerne mandate that every new flat

roof be planted per building code (Dakin 2013, p.140).


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Due to the filtering effect of the plants and the growing medium, stormwater that

drains off a green roof is cleaner to some extents. Not only that it filters the water of some

pollutants such as potassium, phosphorus, calcium, magnesium, etc; but green roofs also

neutralize acid rain by filtration.

Another example of benefits of vegetation in the urban environment is the air purification

capability of plants that can improve air quality by removing air pollutants and trapping them

into their leaves. Because of the rapid deterioration of the urban environment, air purification

capability of vegetation has been receiving increasing attention. Even though trees seem to

have a low impact on the temperature within the city because they are distributed, since there

are so many they can actually have a big impact. On a sunny day the evapotranspiration of a

tree alone is able to cool with a power of 20-30 kW, a power comparable to more than 10 air-

conditioning units (Kleerekoper 2012, p.32).

There have been many discussions about how green a green roof is, and from my

research in literature and empirical data I have found different opinions about it. The reason

of this question is the fact that manufacturers use similar layers and materials for green roofs;

however each manufacturer has developed its own system. General data about green roof

systems are available on the market and virtual media but information about production and

installation process, specific content of substances and engineering technical information is

kept away from public as trade secrets in most cases in order to achieve competitive

advantage on the market.

In general, green roof materials usually use low density polyethylene and polypropylene

(polymers) materials in order to reduce the weight on the roof. Even though green roofs are

seen as a sustainable solution, the production process of polymers is highly polluting; and

because of the long time it needs to biodegrade in landfills, rather than producing new ones it

is preferable to recycle and reintroduce them into the market. It is important to keep in mind

that the manufacturing process of low density polyethylene and polypropylene has high

negative impact towards the environment; however the pollution released into the air due to

their production process can be balanced in the long run, in about 13-32 years depending on

the green roof type.


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‘Some producers are using systems which are 100% degradable, but then the whole system is

not functioning any longer than 3-5 years, and that is not sustainable. A green roof should

live forever, just like a biotope does in nature.’ – says Torben Hoffmann from BygGros A/S 6

Nevertheless, it is still beneficial to install polymers on green roofs, but it is recommended to

explore materials that could replace the current use of polymers to increase the sustainability

impact.

Some studies revealed that extensive green roofs require less materials compared to intensive

green roofs due to their layer thickness. However, intensive roofs usually have bigger plants

and vegetation and they have a higher air dilution rate compared to extensive green roofs. As

a conclusion, despite the fact that they require more materials, intensive green roofs have a

better performance in the life cycle analysis compared to extensive green roofs.

In practice, in Denmark, some professionals use

environmental materials as much as possible in

order to lower the CO2 emission into the

environment. At Moesgård Museum (Figure 7),

in Aarhus the growing medium used on the semi-

intensive green roof is made of recycled

materials such as crushed bricks and tiles, leca

nuts and organic materials (compost)7. Taking

into consideration that the growing medium is

20cm thick and covers almost 10.000m2 proves that Danish professionals think not only

about minimizing the construction costs but also about the environment by using sustainable

materials as much as possible.

‘If a green roof system should be really ‘green’ it is necessary to have a sustainable and local

production. – says Anja Pelle from BygGros A/S 8

The layers that go below the substrate, usually fabricated out of polymers are a technology

burrowed from civil engineering and the agriculture industry. But some designers such as

Andy Creath continue to look for ways to simplify the layers and reduce the amount of

polymers used. Creath explored the replacement of drainage boards in the drainage layer with

6 Interview with Torben Hoffman from BygGros A/S

7 Interview with Søren Nielsen form DanJord A/S

8 Interview with Anja Pelle from BygGros A/S

Figure 7


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gravel where the roof can withstand more weight. By using a moisture mat and 50mm of

gravel topped with a fiber fabric, he gained an extra 50mm of space for the plants. This extra

50mm will allow plants to thrive in a more oxygenated space and will give roots more space

to grow. As a result, the system increases the potential substrate depth with 50mm and

because most of the time aggregate is less expensive, this solution proves to be a financial

benefit (Dakin 2013, p.221).

In Spain, a research team conducted an experiment on the use of rubber crumb in green roofs

focusing on the energy and environmental benefits. Instead of using porous stone materials

they investigated the possible use of rubber crumb as drainage layer and compared the two in

terms of optimum balance rate between air and water.

They found out that the use of rubber crumbs saves a big amount of energy in comparison to

the use of current commercial materials considering the energy need for transformation

process. Besides that, using rubber crumbs will solve the problem of disposing waste tires,

and they are also a good substitute for stone materials used in the drainage layer in terms of

insulation.

If you have ever been on a roof deck in a hot summer day, you can distinguish the

temperature difference of the sun on the top of the building and at the ground. Not only that

plants and components of the assembly mitigate9 the temperature of a green roof making it a

more pleasant place to be but they also protect the roof’s waterproofing membrane from

ultraviolet lights and the degrading effects of extreme temperatures.

In general, green roofs are regarded as

mediums that can reduce the

temperature of a roof. For example, in a

hot summer day, a green roof can

reduce the temperature of a black roof

from 80o

to 27oC (Sadaatian 2012,

p.161). This efficiency has been

considered as equal to the brightest

possible white roofs. The graphic in (Figure 8) illustrates the temperature fluctuations on a

black conventional roof, a white roof, and a green roof between 5 and 14 June 2008. I have

9 Mitigate – reduce, lessen - http://thesaurus.com/browse/mitigate

Figure 8

http://thesaurus.com/browse/mitigate


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observed that on the black conventional roof the temperature has the highest values while on

a white and green roof are lower, with a more constant value for the latter.

From the category of cool roofs, white roofs are also considered to reduce energy costs, but

they have the disadvantage of having to be cleaned regularly in order to stay highly reflective

and work at best performance. Moreover, compared to green roofs, they do not offer as many

benefits as the former. White reflective roofs are generally made of a single-ply membrane,

that is less durable than a conventional roof or a green roof and it would require a more

frequent replacement and maintenance that not only makes white roof more expensive but

also less sustainable. ‘The argument’ says green roof engineer and designer Charlie Miller,

“is that the white roof is going to go gray, while the green roof will only get better”.

On a conventional flat roof, if the waterproofing membrane is not protected by insulation or

other material it will require to be replaced more frequently, after fifteen or twenty years. For

example, in Germany the membranes under a green roof built some decades ago are intact

even now. Designers there usually plan for a life span of at least thirty to forty years long. In

Portland, Oregon, and intensive roof planted on the top of a parking garage of a federal

building has been working excellently without any leaks in its membrane since 1975 (U.S.

General Services Administration [GSA] 2008b). In the present, there are about 6 to 9 million

tons of roofing material waste added to landfills every year in the United States. Maybe it is

too early to make conclusive judgments about green roofs in North America, but the

experiences are promising. Having less frequent roof replacements is better not only for the

environment in terms of production and waste but as well as for the property owners in terms

of investment. The longer life span is another justification why green roofs are more

expensive than simple conventional roofs.

Even though Germany is a world leader in green roof technology, they are not amongst the

first that used this environmental solution. More than twelve centuries after the gardens of

Semiramis, Vikings were using as well green roofs and green houses. This population located

in northern Europe were using between eight and eleventh century, green roofs as an energy

solution in order to protect the building envelope against thermal dispersions, wind and rain.

In the first half of the twentieth century Le Corbusier, Frank Lloyd Wright, and Walter

Gropius started to implement green roofs and green gardens in their projects. After the

reinforced concrete appeared around 1960’s new structural possibilities allowed green roofs

to be widely implemented in new buildings in several Central and Northern European


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nations. Even today, the Færøer Islands, situated between Norway and Iceland, reveal many

examples of dwellings equipped with old-style green roofs.

An economic opportunity of green roofs is achieved in the Northern Europe, where they

contribute in reducing the winter heating need and costs. The evaporating cooling effect and

the low maintenance cost because of the abundance of rainfall imply satisfactory

performances by all types of vegetation. Green roofs use the vegetation layer to protect the

building environment by reducing the thermal loads from solar radiation and air temperature

before entering the building. The protection from extreme temperatures can also reduce

energy costs. Moreover, the growing medium gives added insulation properties to the roof

and the water content increases thermal inertia of the structure. Because a green roof is a

dynamic system, with varying air and moisture content and biomass, in some conditions it

can act as an insulator, while in others a thermal mass effect will act to reduce the

temperature values above and beneath the roof as the system absorbs and slowly releases

heat.

Despite its high initial costs, over the long run green roofs are an economical option

considering their energy saving. To be considered that the total amount of energy savings of

green roofs is most significant for single story buildings and less for other types. In fact, in

multistory buildings, the effect is almost insignificant for the third story below the green roof

and lower.

Studies revealed that temperature fluctuations can be significantly decreased in

summer periods with a green roof substrate layer of 100mm thickness. As example, a

research team from the National Research Council of Canada compared in their study two

different green roof systems, each with 75-100mm of light weight growing medium and a

steel decked reference roof. The result pointed out that green roofs (in Canada) could reduce

the heat gain by an average of 70-90% during summer periods and could prevent heat loss by

10-30% during winter periods (Saadatian 2012, p.161).

In warm climates, green roofs are appropriate for decreasing the energy demand for space

cooling, with an annual reduction of energy between 1-11% in Tenerife and Sevilla (Spain),

and 2-8% for Rome (Italy).

Green roofs are poorly appropriate in hot and also cold climates if water costs are considered,

thus making them moderately suitable only when rainfall is very significant. As a solution,


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installing a watering smart controller could improve the maintenance quality and keep the

irrigation costs low. For safety reasons, it is vital to know that the stored water on a green

roof should not be accumulated for periods longer than three weeks because the stagnant

water could induce risks of bacteria and fungi, dangerous for people and pumping devices.

In order to show that green roofs offer benefits in winter heating as well as summer cooling

reduction costs, in the past decade there have been many studies conducted to prove these

arguments. In Europe, recent directives strongly promote the energy savings for the summer

air-conditioning (Ascione 2013, p.845). The most important principle of a functioning green

roof is the evapotranspiration of water, which induces the evaporative cooling that dissipates

the sensible load connected to the solar radiation by means of a latent heat transfer. This

phenomenon implies cooling energy savings. In order to achieve clear benefits, the design

and construction of a green roof should be precise, also eliminating the thermal bridges, water

losses and infiltration.

Because in the United Kingdom more than half of the building stock was built before

any roof insulation was required, it is older buildings that could benefit most if green roofs

are implemented. The case of retrofitting existing buildings is therefore reviewed and found

that there is a strong potential for green roof retrofit in the UK. Green roofs can significantly

reduce energy use in buildings with poor insulation values, both in summer cooling and

winter heating, but modern buildings, built to the 2006 UK building regulations will have

better U-values because of the insulation quality and green roof will have little impact on

reducing the energy consumption.

Intensive green roofs are real hanging gardens that necessitate substantial costs in terms of

installation, maintenance and irrigation. The substrate layers are complex and have high loads

and because of that the building structure must be carefully evaluated. In most cases an

intensive green roof assembly will not allow the installation on existing buildings, but on the

other hand extensive green roofs are better suited for retrofitting. They require low initial

costs and low maintenance requirements, and they are lightweight and have low layer

thickness. Extensive green roofs are the preferred option for retrofitting onto existing

buildings because of their structural capacity that can take extra loads to some extents due to

the improved structural efficiency of modern analysis, design, and construction methods.

UK’s medium-rise buildings with concrete roofs could probably be retrofitted with a green

roof without any additional structural modifications, but before designing the retrofitting a


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structural survey is recommended in most cases in order to determine a building’s roof load

capacity.

Buildings justify for almost half of the primary energy consumption in developed countries,

hence also the CO2 emissions. A large amount of this energy is used to maintain internal

building temperatures by heating and cooling systems. Older buildings can greatly benefit

from the additional green roof layer because it reduces the proportion of solar radiation that

reaches the roofing beneath and also offers additional insulation values, hence reducing

annual energy consumption. Even though many studies assess the potential energy savings of

green roofs, it should be noted that these are predominantly for climates warmer than UK. As

a conclusion green roofs are seen more as a passive cooling technique rather than as a thermal

insulator in the winter. In the summer the exposed area of a black roof can reach 80oC when

the equivalent area beneath a green roof is only 27oC. The reasons why green roofs cool

down is because of latent heat loss and improved reflectivity or incident solar radiation.

There are suggestions that green roofs cool as effectively as the brightest possible white

roofs, with an equivalent albedo10

(the fraction of incident electromagnetic radiation reflected

by a surface) of 0.7 – 0.8, compared with the typical 0.1 – 0.2 of a bitumen roof. Some filed

studies shown that in hot conditions the heat accumulated by a conventional roof during the

day continued to enter the building also during the night. Another study has shown that by

measuring the air temperature at various heights above the vegetation on a green roof, the

values were reduced significantly and also continued to cool the ambient air throughout the

night (Castleton 2010, p. 1583). Air conditioners cool interior spaces by discharging heat to

the outside, as a result the surrounding temperature increases. And because HVAC (heating,

ventilation, and air conditioning) efficiencies depend on input temperature, the costs of

neighboring air conditioning will use more energy to cool the air coming in the building, thus

increasing the energy costs. But if a green roof is implemented, then the lack of heat around

the building could increase the efficiency of air-cooling and ventilation systems and also

lower the energy costs.

Unless there is a change in use, commercial and institutional buildings do not require a

planning permission and usually they are repaired / refurbished every 15-20 years. This could

be a great opportunity for building owners to implement a green roof which could offer

10

Definition taken from dictionary - http://www.thefreedictionary.com/albedo

http://www.thefreedictionary.com/albedo


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substantial energy saving throughout the year and also reduce the CO2 emitted into the

atmosphere.

Data from Lambeth Council, which is based on real green roof retrofit experience, suggests

costs between £120 - £180/m2.

The Ethelred estate (Figure 9), in Kennington, Bauder constructed an extensive system of

4000m2 in 2005 with a total cost of £716,000 equating to £179/m

2.

In terms of whole-life cost analysis, the calculated Net Present Value (NPV) of a green roof

is estimated around 10 – 14% more expensive than a conventional roof over a period of 60

year lifetime. If energy costs will increase or stormwater prevention will become a higher

public priority, then green roofs will become more economically attractive and there will be

more opportunities for the technology to be implemented on a large scale.

Green roofs are engineered ecosystems and in order to achieve sustainable benefits it

is important that all their parts and acting agents be understood. Amongst the basic things one

should know what questions to ask and what data to research and collect. For example, to be

able to investigate biodiversity on green roofs it is important to understand the context of the

roof to its environment. Is it located in the urban environment or is it in suburban or rural? –

The importance of this question is reflected in the opportunities for food and cover available

in each of those environments so that biodiversity can thrive. In general, rural environments

can offer more opportunities compared to suburban and urban thus the implementation of a

green roof in that rural environment would not have such a big impact while in the latter ones

there is lack of vegetation and the living conditions are scarcer.

In general, biodiversity is defined as the amount of variation within an ecosystem, biome,

continent, or planet. But when we define biodiversity in the urban environment we often pick

only the pretty inhabitants or the ones we believe to be beneficial such as bees, butterflies or

Figure 9


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birds, but true diversity in the urban context means all living creatures, ants, beetles, rats,

cockroaches, pigeons, spiders, and so on. Each one of these serve a purpose, and urban

rooftops, especially the ones with low- or no human interaction are the perfect places to

facilitate wildlife habitats.

There are strong unreliable evidences that green roofs attract insects and birds, but the extent

to which green roofs can have a significant impact on wildlife habitat is unclear because of

the lack of available data. Even though research on this subject is in early stages, European

studies on mature green roofs suggest that when properly designed to accommodate wildlife

and offer food and shelter, they can have an important role in sustaining urban biodiversity.

There are examples on European green roofs that have been found to be ecologically rich

with abundance of insects, birds, wildlife and plants.

In the United Kingdom, extensive green roofs are a key

part of the London Biodiversity Partnership plan to

restore the black redstart population11

(figure 10). This

protected bird species prefers urban habitat but because

of lack of appropriate insect life to support, the flying

population is in danger. Recently, many sustainability

activists and noticeable results have convinced the U.K.

Green Building Council that green roofs are among the

most effective ways to restore biodiversity in urban

environments.

In Zürich, Switzerland, one of the world’s oldest green

roofs built in 1914, (Orchid Meadow on the Moos

Water Filtration Plant12

) provides habitat for 175

species of plants including 9 native species of rare or

endangered orchids (figure 11). The most interesting

part of the story is that this roof was not planned to be

a green roof and plants have naturally colonized there.

The Moss filtration plant processes water from Lake Zürich with sand filters to produce

drinking water. The water is pumped from the lake into the building and as it slowly filters

11

The black redstart bird - http://www.rspb.org.uk/wildlife/birdguide/name/b/blackredstart/index.aspx 12

The Moos filtration plant - http://www.greenroofs.com/projects/pview.php?id=680

Figure 11

Figure 10

http://www.rspb.org.uk/wildlife/birdguide/name/b/blackredstart/index.aspx

http://www.greenroofs.com/projects/pview.php?id=680


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through a layer of sand, clean drinking water comes out. The building was one of the first

reinforced concrete buildings to be constructed in Zürich, with a ceiling of 8cm thick slab

beams finished with a layer of 2cm mastic asphalt. After more than 90 years the two layers

have finally combined but without any negative impacts on the impermeability of the

membrane or the vegetation. The only reconstructions carried out after all these years were at

the edges of the roof, besides that the membrane is fully functional.

In the United States, some green roofs are being designed specifically to attract endangered

butterflies and other species; moreover some research has surprisingly found high levels of

biodiversity even on the simplest extensive green roofs.

The Chicago City Hall reporting on bird diversity demonstrates that if a varied habitat

structure is provided, wildlife will find it (Dvorak 2010, p.210).

Some people think that all green roofs can perform as an excellent wildlife habitat and some

believe that using native plants on a green roof makes that roof a substitute for habitat but the

reality is different. While on a green roof will usually offer possibilities for biodiversity, it is

impossible to recreate at-grade habitat on the roof of a building. Even though a green roof can

offer a better environment compared to a traditional black roof or a parking lot in a densely

built city, it is not a replacement for the open green space destroyed by urban development.

While projects in Europe show that green roof design for wildlife habitat can be successful in

urban environments, also demonstrate how complicated it is to achieve that success. Habitat

can be replicated, but it cannot be recreated.

Traditionally, the history of landscape design has been more about conquering or taming

nature than about embracing it; however we need more animals and green spaces in our cities

for us to be healthy and happy. In order to make this happen, green roof designers have the

unique opportunity to lead the way by learning methods that allow nature to feed itself and

thrive in urban environments. This new age of coexistence could be framed as an age of

integration, where the relation between human and nature is strongly encouraged.

There are many possibilities for growing plants when rethinking the rooftop of a

building. If you are going to plant up there, why settle for modest succulents when there are

so many possibilities to restore some native flora, provide wildlife habitat, or serve as

amenity spaces. Besides offering possibilities for biodiversity, green roof can serve as farms

for growing vegetables and food crops. Even though it is much easier and more economical


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to grow vegetables and other food crops on ground, on a small scale and with attention to

irrigation, maintenance, and fertility requirements, food can be grown on roof tops as well. In

general, this can be done only on intensive green roofs because of the medium depth plants

need to grow their roots and prosper; however there have been successful cases where an

extensive system was used. In an urban environment, such food growing spaces can function

as community gardens and places for educational programs for children who have little, or no

access to country-side farms and growing gardens.

Food production on rooftops is becoming more

and more popular nowadays. In the United

States, in Greenpoint, Brooklyn, there is a 560

m2 rooftop farm (figure 12) that sells

vegetables grown on the building’s own roof.

Some people might find it unessential to grow

food on roof tops, but having the opportunity

to do this in an urban environment where there

is lack of vegetation allows you to go out of

the concrete jungle for a while and experience the wonderful work of nature. Just imagine

how it feels to walk around mounded beds flushed with greenery while you can look over the

East River towards the skyline of Manhattan.

In Vancouver, growing food seems to be a shared passion among local people. The Fairmont

Waterfront Hotel herb garden is one of the city’s first green roofs with a garden of 195 m2

planted with over sixty varieties of herbs, fruits, vegetables, and edible blossoms which are

used in the hotel kitchen. Hidden behind the diving board of the swimming pool adjacent to

the garden, blackberries prosper. The hotel management is also proud of the eight bee hives,

safely nested below the roof main deck13

. Not only that honey bees are one of the most

important pollinators, but pollination is considered to be the single most important reason for

biodiversity when it comes to think about survival of human species. Without pollination,

there will be not enough food to sustain life and diversity on our planet would diminish

significantly.

13

Fairmont Waterfront Hotel harvest -

http://www.youtube.com/watch?feature=player_embedded&v=hZcR8x0OgFk

Figure 12

http://www.youtube.com/watch?feature=player_embedded&v=hZcR8x0OgFk


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Another green roof initiative situated on the

other side of Vancouver, in Richmond, is the

BMW car dealership14

where the owners have

invested into an extensive green roof and planted

a large variety of plants such as alpine and

regular strawberries, blueberries, red currants,

banks of lavender, roses, and other herbs. The

dealership is in an agreement with the food bank

and supplies them with vegetables grown on the

green roof’s community garden. As mentioned in

the previous case of Fairmont Waterfront Hotel,

here as well the owners are combating the

worldwide phenomenon CCD (Colony Collapse

Disorder) and have given special attention to

their honeybees and ensured a special location

out of the coastal winds, behind the espaliered

apple trees( figure 13), that grow in just 30cm of soil. The apiary (figure 14) consists of 3

colonies that host approximately 150,000 bees which pollinate the green roof gardens and the

surrounding environment15

.

These urban roof tops serve as perfect places to facilitate not only wild life diversity but also

plant and harvest a large variety of food crops. Having these opportunities proves once more

that green roofs can be beneficial to the urban environment.

Including green roofs and green gardens into building design in some cities and

communities incentives and policies are offered that guide green roof implementation. One

type of indirect subsidy is allowing developers to use green roofs as mitigation for the

provision of open space. In Chicago, for example, all projects with residential units to

provide open space require paying an impact fee; moreover if a green roof is implemented in

the project then the developer can receive a credit on the impact fee if the green roof is

accessible to the residents of the building or the public.

14

Richmond BMW dealership – http://www.youtube.com/watch?v=P6G8DQ6UVJM 15

Richmond BMW dealership (honey bees) - http://www.youtube.com/watch?v=ixspasu_kmM

Figure 13

Figure 14

http://www.youtube.com/watch?v=P6G8DQ6UVJM

http://www.youtube.com/watch?v=ixspasu_kmM


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In Germany, the world leader of green roof implementation, taxes are collected for

anticipated stormwater control or usage fees, and owners of waterproof roof covers are

perceived a 100% utility surcharge. Among that, thirteen German cities benefit a reduction of

between 50 and 80% of the utility fee when installing a green roof.

In other parts of the world, such as Singapore, the NParks program founds up to 50% of the

installation costs on green roofs to increase the level of sky rise greenery and enrich the city’s

image in high activity open spaces.

In Tokyo, in 2011, in an effort to combat the urban heat island effect, the “Tokyo Plan 2000”

was established, requiring new buildings greater than 1000 m2 or over 0.1ha to green at least

20% of their usable roof space (Dakin 2013, p.140).

Other incentives are offered for using green roofs to filter storm water before it reaches the

ground. Green roof approach on infrastructures are one method of decimating the pollution

on navigable waterways by capturing and filtering storm water in order to maintain and

restore natural hydrologies. Green roofs are part of the solution of the Clean Water Act,

because they slow stormwater down and filter it of pollutants.

In general, green roofs are an integral part of a social or cultural context that examines what

is happening in and around the potential site regarding humans and social interaction. But

when it comes down to observation, there is no substitute for an on-site visit. Being there in

person allows you not only to feel the wind, or foresee limitations and opportunities, but also

think about what type of garden is most suitable.

Even a simple green roof and a plant

palette can provide an attractive and comfortable

amenity space if the building’s loading capacity is

able to accommodate people, furniture and other

accessories. An amenity roof is an aesthetic

upgrade from a basic extensive green roof to a

space that might include gatherings, or serve to

beautify a view out a window or from a

neighboring building (figure 15).

Amenity green roofs compared to basic extensive green roofs have several advantages, such

as a more dynamic, textural, and colorful appearance and their better looks and accessible

Figure 15


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space, if available, might increase the value of marketability of the building. Some of the

disadvantages to amenity green roofs include higher constructions and maintenance costs and

the possible need of a more complex assembly compared to the basic green roof.

As a medical recommendation, being outside

and doing physical activities is far better than

being stuck in a gym looking at the screen.

Forward thinking managers often convert

rooftops to play areas that are available for

their employees. Some of them include

swimming pools, basketball- or tennis courts.

For example, in the heart of Aarhus, Denmark

the roof top of the Bruuns Galleri serves as an

amenity for golf players with a track of 18

holes under the blue sky, six levels above the

ground (figure 16).

Another green roof implementation in Denmark

can be seen in Horsens at the Vitus Bering

Innovation Park (figure 17). The building was

constructed in 2009 and since then a sedum

green roof with blooming plants and grass

beautifies the place which offers a great

panoramic view around the city.

Other institutions, such as hospitals and schools

create roof gardens with the needs for children in

mind (figure 18). One way to see it is the

opportunity for designing vegetable gardens on

the top floors of educational high-rise buildings

to provide experiences to children who rarely or

never see countryside farms. These kinds of

solutions are increasingly happening on

building’s roof tops in urban environments.

Figure 16

Figure 18

Figure 17


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In Switzerland, city of Basel, a water park created on top of a parking garage by artist Jean

Tinguely attracts thousands of visitors each year. The place is filled with moving sculptures

that spout water.

Just about everybody has experienced flying above a city on a clear day and just before

landing, from those tiny airplane windows, are able to preview the urban landscape. For a few

magical moments you have that unique bird’s eye view from which you can observe all the

building rooftops that come out from small forests or parks. In those moments designers have

realized that urban rooftops are blank canvasses of black, grey, or white nuances that are just

waiting to be greened.

5. Conclusion

Assuming that the best landscape architect is nature and the whole purpose of a green

roof is to create an ecosystem where biodiversity can live and prosper then we also have to

accept that bringing nature into the urban space will solve many of our problems and needs.

In the last three decades green roofs have been implemented into urban environments in order

to improve the ecology situation which humans have neglected while focusing more on

modern architecture.

From a first point of view green roofs have existed since centuries ago in the gardens

of Semiramis which implemented them on top of their buildings in the middle of the desert.

Then the idea was developed in Scandinavian countries where green roofs have been used to

insulate the building envelope against thermal dispersions. Later on after the Second World

War, when reinforced concrete was broadly used green roofs were implemented on a large

scale in Europe, thus giving Germany the opportunity to become the world leader in this

technology with more than three decades of experience.

Nowadays green roofs are implemented worldwide, some countries using the German FLL

guidelines, others using their own ‘know-how’ and they observe and reflect upon the

opportunities green roofs can offer.

During this report I have been analyzing examples of green roof implementation from

around the world, from Europe to North America, and Asia. Together with the written

literature research and empirical data collected from interviews with professionals in the


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green roof industry and online publications and articles I have formed this document that

presents how green roofs can influence the urban environment.

I have been through many study cases of green roof projects worldwide that present some of

the advantages and disadvantages of implementing this technology on building’s roof tops

and despite their high costs, the results seem promising. Of course, there are still many

improvements to be done but as green roofs continue to be a growing and integral part of our

urban environments, ten, twenty, or thirty years from now we will have more examples to

reflect upon as well as more experience in the field.

Even though green roofs investors expect fast responses and pay-backs, the reality isn’t by

their side and they will have to have patience and let the professionals do their job. Great

results take time, and the famous quote says it best “Rome wasn’t built in a day”.

Energy saving during hot and cold season, mitigation of urban heat island effect and

CO2 emissions, habitat and biodiversity opportunities, cultivation of food and crops, roof

membrane protection and life span improvement, stormwater retention, filtering and runoff

control, cooling of urban environment, and job opportunities are just some of the advantages

compared to the high costs for maintenance and construction of green roof implementation

we face nowadays.

Considering all those benefits I believe that green roof technology will be more

affordable in the near future and their implementation on a large scale in the urban

environments will be an important step to a cleaner and more sustainable habitat for humans

and nature to co-exist in the same place.

As a future perspective, I believe that this dissertation report has had a great influence upon

my learning activity due to the variety of activities and research I made in order to create it,

as well as great asset for my portfolio in the future job search. The complexity of gathering

the information from written literature, internet articles, on-line publications and videos, as

well as interviews with professionals from the green roof industry, proved to be a challenge

that I managed to overcome with great passion and interest.


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To end-up this report I would like to share the vision of the Swiss architect Le

Corbusier who almost a century ago wrote his sentiments in his book Le Petite Maison16

(the

little house):

“We climb up to the roof – a pleasure known to some civilizations in former centuries.

The reinforced concrete forms the terrace roof and, with 20 or 30 centimeters of earth, the

“roof garden.” Here we are on top! We are in the middle of the dog-days; the grass is

parched. What does it matter, for each tiny leaf gives shade and the compact roots insulate

from heat and cold…Pay attention! It is towards the end of September. The autumn flowers

are blossoming and the roof is green once more, for a thick carpet of wild geraniums has

over grown everything. It is a wonderful sight. In spring, the young grass sprouts up with its

wild flowers; it is high and luxuriant. The roof garden lives independently, tended by the sun,

the rain, the winds, and the birds which bring the seeds.”

16

Fragment taken from The professional design guide to green roofs – Dakin 2010, p.277( see list of references)


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6. List of illustrations

Figure 1 (front cover) - Green roofs 2010/2030

Link<https://www.facebook.com/photo.php?fbid=483709078365793&set=a.2467596020607

43.58106.246755835394453&type=1&theater>

Figure 2 – Rockefeller Center, New York, USA

Link < http://weirdcreative.com/astounding-nature-in-the-middle-of-big-cities-around-the-

world-18-beautiful-rooftop-gardens-461/>

Figure 3 – Sedum green roof (Diadem 50)

Link < http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/sedumtag-

50>

Figure 4 – 8 Tallet, Copenhagen, Denmark

Link < http://designkbh.blogspot.dk/>

Figure 5 – Intensive roof (Diadem 1200)

Link < http://www.byggros.com/da/produkter/gronne-tage/gronne-tage-systemer/diadem-

1200>

Figure 6 – Urban heat island effect illustration

Link < http://www.urbanreleaf.org/get-educated/benefits-of-trees>

Figure 7 – Moesgård Museum (on-site picture)

Figure 8 – Scan from Green roof manual p.31 (see list of references for information about

the book)

Figure 9 – Ethelred estate, Kennington, UK

Link < http://www.homeprotect.co.uk/Media/278340/ethelred_roof.jpg>

Figure 10 – Black redstart bird, UK

Link < http://www.rspb.org.uk/wildlife/birdguide/name/b/blackredstart/index.aspx>

https://www.facebook.com/photo.php?fbid=483709078365793&set=a.246759602060743.58106.246755835394453&type=1&theater

https://www.facebook.com/photo.php?fbid=483709078365793&set=a.246759602060743.58106.246755835394453&type=1&theater

http://weirdcreative.com/astounding-nature-in-the-middle-of-big-cities-around-the-world-18-beautiful-rooftop-gardens-461/

http://weirdcreative.com/astounding-nature-in-the-middle-of-big-cities-around-the-world-18-beautiful-rooftop-gardens-461/



http://designkbh.blogspot.dk/



http://www.urbanreleaf.org/get-educated/benefits-of-trees

http://www.homeprotect.co.uk/Media/278340/ethelred_roof.jpg



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Figure 11 – Orchid plantation on Moos Water Filtration Plant, Zürich, Switzerland

Link < http://www.greenroofs.com/projects/pview.php?id=680>

Figure 12 – Eagle Street farm, Brooklyn, NY, USA

Link<http://thescoutmag.com/assets/0000/2575/article_eaglestfarm_benefit_01_grid_4.jpg?1

313973662>

Figure 13 – Honey bee apiary, Auto West BMW Vancouver, Canada

Link < http://www.richmond-news.com/news/richmond-businesses-vying-to-be-greenest-

1.495737>

Figure 14 – Honey bee apiary, Auto West BMW Vancouver, Canada

Link < http://green.autowestgroup.ca/portfolio/autowestbmw/>

Figure 15 - Green roof at Mountain Equipment Coop, Toronto, Canada

Link < http://www.inspirationgreen.com/urban-institutional-green-roofs.html>

Figure 16 – Overview of minigolf course, Aarhus, Denmark

Link < http://www.panoramio.com/photo/28478635>

Figure 17 – Green roof over Vitus Bering Innovation Park, Horsens, Denmark (on-site visit)

Figure 18 – Green roof garden on top of educational building

Link < http://www.playground-landscape.com/en/article/view/349.html>

!Note: more illustrations of green roofs are attached to the enclosures.


http://thescoutmag.com/assets/0000/2575/article_eaglestfarm_benefit_01_grid_4.jpg?1313973662

http://thescoutmag.com/assets/0000/2575/article_eaglestfarm_benefit_01_grid_4.jpg?1313973662

http://www.richmond-news.com/news/richmond-businesses-vying-to-be-greenest-1.495737

http://www.richmond-news.com/news/richmond-businesses-vying-to-be-greenest-1.495737

http://green.autowestgroup.ca/portfolio/autowestbmw/

http://www.inspirationgreen.com/urban-institutional-green-roofs.html

http://www.panoramio.com/photo/28478635

http://www.playground-landscape.com/en/article/view/349.html


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7. List of references:

7.1. Books:

‘The green roof manual’

Author(s): Edmund C. Snodgrass and Linda McIntyre

Published by: Timber Press

Release date: 2010

Place of publishing: Portland | London

‘The Professional Design Guide to Green Roofs’

Author(s): Lisa Lee Benjamin, Karla Dakin, Mindy Pantiel

Published by: Timber press

Release date: 2013

Place of publishing: Portland | London

‘Sustainable Urban Environments – an ecosystem approach’

Author(s): Ellen van Bueren, Hein van Bohemen, Laure Itard, Henk Visscher

Published by: Springer

Release date: 2012

Place of publishing: London | New York

‘City Design’

Author(s): Jonathan Barnett

Published by: Routledge

Release date: 2011

Place of publishing: USA and Canada


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7.2. Articles:

ELSEVIER, 2013. A review of energy aspects of green roofs [pdf].

Available at: <http://www.sciencedirect.com.ez-

aaa.statsbiblioteket.dk:2048/science/article/pii/S136403211300124X>

[Accessed September 10th

2013]

ELSEVIER, 2012. Acoustic effects of green roof systems on a low-profiled structure

at street level [pdf].


aaa.statsbiblioteket.dk:2048/science/article/pii/S0360132311003532#>


2013]

ELSEVIER, 2012. Cool and green roofs. An energy and comfort comparison between

passive cooling and mitigation urban heat island techniques for residential buildings

in the Mediterranean region [pdf].

Available at:

<http://www.sciencedirect.com/science/article/pii/S0378778811004129>


2013]

ELSEVIER, 2012. A field study to evaluate runoff quality from green roofs [pdf].

Available at:

<http://www.sciencedirect.com/science/article/pii/S004313541100844X>


2013]

ELSEVIER, 2010. Effect of green roof on ambient CO2 concentration [pdf].

Available at:



2013]

ELSEVIER, 2010. Green roof vegetation for North American ecoregions: A literature

review [pdf].


aaa.statsbiblioteket.dk:2048/science/article/pii/S0169204610000782>


2013]

ELSEVIER, 2013. Green roofs in European climates. Are effective solutions for the

energy savings in air-conditioning? [pdf].

Available at:


http://www.sciencedirect.com.ez-aaa.statsbiblioteket.dk:2048/science/article/pii/S136403211300124X

http://www.sciencedirect.com.ez-aaa.statsbiblioteket.dk:2048/science/article/pii/S136403211300124X

http://www.sciencedirect.com.ez-aaa.statsbiblioteket.dk:2048/science/article/pii/S0360132311003532


http://www.sciencedirect.com/science/article/pii/S0378778811004129

http://www.sciencedirect.com/science/article/pii/S004313541100844X






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2013]

ELSEVIER, 2009. Green roofs in sustainable landscape design [pdf].




2013]

ELSEVIER, 2009. Green roofs in sustainable landscape design [pdf].




2013]

ELSEVIER, 2010. Green roofs; building energy savings and the potential for retrofit

[pdf].

Available at:



2013]

ELSEVIER, 2011. Greenery on residential buildings: Does it affect preferences and

perceptions of beauty? [pdf].

Available at:

<http://www.sciencedirect.com/science/article/pii/S027249441000099X>


2013]

ELSEVIER, 2012. How to make a city climate-proof, addressing the urban heat

island effect [pdf].


[Accessed September 23rd

2013]

U.S. Environmental Protection Agency, 2004. Guidelines for Water Reuse [pdf].

< http://water.epa.gov/aboutow/owm/upload/Water-Reuse-Guidelines-625r04108.pdf


2013]

Skælskør Anlægsgarnere A/S, 2010. Grøn tage[pdf].

<http://www.skag.dk/files/Groenne_tage/PPT_SKAG_Grnne_tage_samlet_3.pdf>

[Accessed October 8th 2013]






http://www.sciencedirect.com/science/article/pii/S027249441000099X



http://www.skag.dk/files/Groenne_tage/PPT_SKAG_Grnne_tage_samlet_3.pdf


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7.3. Internet links:

Link address: http://www.greenroofs.com/

Page accessed: 27/08/2013

Link address: http://www.youtube.com/watch?v=pp79mGpomf4


Link address: http://www.greenroofs.com/projects/pview.php?id=680

Page accessed 18/09/2013

Link address:



http://www.greenroofs.com/

http://www.youtube.com/watch?v=pp79mGpomf4




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8. List of enclosures

8.1. Auto-family house – Poland, 2012

8.2. Villa Topoject - Gyeonggido, Korea 2010

8.3. Mountain Dwellings – Copenhagen, Denmark, 2008

8.4. Kastrup Power Plant at Copenhagen International Airport – Kastrup, Denmark, 2005

8.5. Green roofs in Stuttgart, Germany

8.6. Logistics Center - Bondorf, Germany, 1996

8.7. Ford Rouge Plant – Michigan, United States, 1999

8.8. Vancouver Convention Center – Vancouver, Canada, 2009

8.9. Penn State Hershey Children’s Hospital - Hershey, Pennsylvania, United States, 2012

8.10. Green roofs Iceland

8.11. Interview with Anja Pelle from Byg Gros A/S (Sweden)

8.12. Interview with Ulrich Reeh from VegTech A/S (Denmark)

8.13. Interview with Lise Mansfeldt Faurbjerg from Henning Larsen Architects (Denmark)

8.14. Interview with Henrik Windbirk, VIAUC Aarhus lecturer (Denmark)

8.15. Interview with Torben Hoffmann from Byg Gros A/S (Denmark)

8.16. Interview with Søren Nielsen from Dan Jord A/S (Denmark)


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8.1. Auto Family House – Poland, 2012 –

http://www.archello.com/en/project/auto-family-house

http://www.archello.com/en/project/auto-family-house


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8.2. Villa Topoject - Gyeonggido, Korea 2010 - http://www.archdaily.com/161360/villa-

topoject-and/

http://www.archdaily.com/161360/villa-topoject-and/

http://www.archdaily.com/161360/villa-topoject-and/


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8.3. Mountain Dwellings – Copenhagen, Denmark, 2008 -

http://www.archdaily.com/15022/mountain-dwellings-big/

http://www.archdaily.com/15022/mountain-dwellings-big/


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8.4. Kastrup Power Plant at Copenhagen International Airport – Kastrup, Denmark, 2005




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8.5. Green roofs in Stuttgart, Germany.

Steven W. Peck, founder of the Canada-based industry association Green Roofs for Healthy

Cities, says “all you have to do is climb a tall building in Germany, and you’re going to see

green roofs all over the place."

http://urbangreens.tumblr.com/image/914031202

http://urbangreens.tumblr.com/image/914031202


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8.6. Logistics Center - Bondorf, Germany, 1996 -




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8.7. Ford Rouge Plant – Michigan, United States, 1999

Ford's Rouge Plant, at over 450,000 square feet, is the largest green roof in the United States

and saved over $10 million on the installation of a storm water runoff treatment system.

http://www.apexgreenroofs.com/green-roof-benefits.html

http://www.apexgreenroofs.com/green-roof-benefits.html


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8.8. Vancouver Convention Center – Vancouver, Canada, 2009

http://www.alternativeconsumer.com/2010/09/13/green-roof-of-the-day-vancouver-

convention-center/

http://www.alternativeconsumer.com/2010/09/13/green-roof-of-the-day-vancouver-convention-center/

http://www.alternativeconsumer.com/2010/09/13/green-roof-of-the-day-vancouver-convention-center/


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8.9. Penn State Hershey Children’s Hospital - Hershey, Pennsylvania, United States, 2012

http://www.liveroof.com/blog/2012/green-roofs-offer-natural-views-and-access-to-green-

space-for-patients-and-families-at-penn-state-hershey-childrens-hospital/

http://www.liveroof.com/blog/2012/green-roofs-offer-natural-views-and-access-to-green-space-for-patients-and-families-at-penn-state-hershey-childrens-hospital/

http://www.liveroof.com/blog/2012/green-roofs-offer-natural-views-and-access-to-green-space-for-patients-and-families-at-penn-state-hershey-childrens-hospital/


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http://www.prweb.com/releases/Hershey_Childrens/Hospital_LiveRoof/prweb10192342.htm

http://ww1.prweb.com/prfiles/2012/11/30/10192342/LiveRoof_Hershey_8b.jpg



http://ww1.prweb.com/prfiles/2012/11/30/10192342/LiveRoof_Hershey_8b.jpg


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8.10. Green roofs Iceland

http://www.greenfab-media.com/landscape-and-habitat/456/iceland-and-green-roofs

http://www.greenfab-media.com/landscape-and-habitat/456/iceland-and-green-roofs

1

Valer Daniel Rudics (178744)

From: Anja Pelle <[email protected]>

Sent: Wednesday, September 18, 2013 12:04 PM

To: Valer Daniel Rudics (178744)

Subject: SV: Interview about green roofs.

Attachments: image001.png

Categories: Important

Hello Valer Thank you for your email. Please see my answer below. I hope the answer can help you further with your report Med venlig hilsen/Best regards Anja Pelle Teknisk Salgskonsulent

Mobile: +45 22 94 51 23 Email: [email protected]

Byggros A/S • Egegårdsvej 5 • DK-5260 Odense S • Tel: +45 5948 9000 • Fax: +45 5948 9005 [email protected] • www.byggros.com Company of Byggros Holding A/S

Fra: Valer Daniel Rudics (178744) [mailto:[email protected]]

Sendt: 12. september 2013 18:24 Til: Anja Pelle

Emne: Interview about green roofs.

Greetings, My name is Valer Daniel Rudics, I am a constructing architect student at VIA University College in Århus, Denmark. At the moment I am writing my dissertation report which is part of the syllabus for the last semester of my education, and I am writing to ask you several questions. The main subject of my dissertation is green roofs, but my focus is on 'how can

green roofs influence the urban environment?' I would really appreciate if you could take some time and answer the following questions which are part of my research for the empirical data.

1. How 'green' is a green roof? Is the construction sustainable from a material point of view?

That is a very good question and an important one also. First of all the vegetation is making the green roof

‘green’, but what about the system below. I can only comment on our system.

GreenStar

Typewritten Text

Enclosure 8.11.

2

If a green roof system should be really ‘green’ it is necessary to have a sustainable and local production.

Our products is mostly made of recycled material, which is a good way to start, but the products are

produced in Hungary, which we can’t call local.

The substrate is produced in Denmark. We have a depot in Lisbjerg and Næstved, so we don’t have to fare

to our clients.

I don’t thing we that we can call it a cradle to cradle product, but we are working to get it more green.

2. Do you think that there are more financial benefits to retrofit an old building with green roof or to

implement the green roof in a new building? (Could you explain your decision?)

That’s a difficult one! I will say it depends of the benefits you want from the green roof, so I think that you

can get financial benefits in both cases.

I think it depends of the project and which type of green roof, we are talking about.

An intensive green roof will always give a financial benefit because it is possible to make a roof to a place

where people can stay, play or relax. That will give the building an extra value.

An extensive roof can be “just” an extra cost on old and new buildings, but it is also possible to withhold

water on the roof, and thereby min. the costs for a new drain system.

3. What is the clients' opinion when suggesting the implementation of a green roof in your projects?

I think the general opinion is very positive. The most critical point is the financial aspect.

4. It is known that Germany is the world leader in green roof technology. Do you think Denmark is following

the path?

I don’t think Denmark will be comparable with Germany, but we are doing a great job to get there. The

municipalities are making a lots of rules to make sure that the amount of green roofs will grow.

5. Do local authorities encourage the Danish building industry include green roof technology in urban design?

The short answer is yes, a good example is Københavns Kommune.

Looking forward to hearing from you!

Kind regards / Med venlig hilsen

Valer Daniel Rudics Constructing Architect Student

VIA University College Aarhus Halmstadgade 2, 8200, Aarhus Nord

School e-mail: [email protected] Privat e-mail: [email protected] Tlf: 27 89 73 45

Please save a tree and do not print this e-mail! ☺☺☺☺

1


From: Ulrik Reeh <[email protected]>

Sent: Friday, September 13, 2013 5:33 PM




Hi

I´m not shure what this Guldhornet is. Do you mean Snozelhuset??

Short answers to difficult questions will follow below.

I hope you will send your final thesis – thank you and good lcuk

Med venlig hilsen

Ulrik Reeh

Veg Tech A/S Annasvej 2

2900 Hellerup

Tlf.: 3962 6869

Mobil: 2835 6869

[email protected]

www.vegtech.dk


Sendt: den 13 september 2013 10:15

Til: Ulrik Reeh Emne: Interview about green roofs.


green roofs influence the urban environment?' I am writing to you because you have been recommended by my consulting teacher Henrik Windbirk, and he shortly introduced me to the project that you have worked together at “Guldhornet” in Skanderborg. I would really appreciate if you could take some time and answer the following questions which are part of my research for the empirical data.


Depends on which construction you think of and what are your criteria!



Must be the same, but always depending on the actual case!

GreenStar

Typewritten Text

Enclosure 8.12.

2


Differs from nice design, green profile, storm water retention, etc.


the path?

Yes

5. Do local authorities encourage the Danish building industry include green roof technology in urban design?

Yes more and more, but different from municipality to municipality!







10/19/13 Gmail - SV: Interview regarding green roofs.

https://mail.google.com/mail/u/0/?ui=2&ik=94655e90c8&view=pt&search=starred&msg=1414a3a63c6d42a7 1/3

Valer Daniel Rudics <[email protected]>

SV: Interview regarding green roofs.

Lise Mansfeldt Faurbjerg <[email protected]> Mon, Sep 23, 2013 at 11:50 AMTo: "[email protected]" <[email protected]>

Hi Valer,

I’m sorry for the late answer. See answers below marked with blue. In case you quote any answers in your report

with the mentioning of Henning Larsen Architects, please run the quotes by me before you print it.

Good luck on your thesis!

Best regards,

Lise Mansfeldt Faurbjerg

____________________________________________

Lise Mansfeldt Faurbjerg

B. eng. Architectural Engineering

BA Aesthetics & Culture

Direct tel +45 8231 3179

Henning Larsen Architects A/S

Vesterbrogade 76

1620 Copenhagen V

Denmark

Tel +45 8233 3000

www.henninglarsen.com

____________________________________________

From: Valer Daniel Rudics (178744) [mailto:[email protected]] Sent: 11. september 2013 10:17To: Henning Larsen Architects - MailSubject: Interview regarding green roofs.

tel:%2B45%208231%203179

tel:%2B45%208233%203000

http://www.henninglarsen.com/

mailto:[email protected]

GreenStar

Typewritten Text

Enclosure 8.13.



Greetings,

My name is Valer Daniel Rudics, I am a constructing architect student at VIA University College in Århus, Denmark. At the

moment I am writing my dissertation report which is part of the syllabus for the last semester of my education, and I am

writing to ask you several questions. The main subject of my dissertation is green roofs, but my focus is on 'how can

green roofs influence the urban environment?'

I would really appreciate if you could take some time and answer the following questions which are part of my research for

the empirical data.

1. How 'green' is a green roof? Is the construction sustainable from a material point of view? Depending on the context

and the local climate a green roof can be more or less green. As a rule of thumb we regard green roofs as highly green

feature – but a decision about a green roof should be accompanied by clear reasons for the functionality of the green roof.

Is it a feature for the local water management? Is it part of an Urban Cool Island strategy? Is it for leisure purposes? Or

bio-diversity? Or, or, or…? These questions should be explicitly answered.

2. Do you think that there are more financial benefits to retrofit an old building with green roof or to implement the

green roof in a new building? (Could you explain your decision?) This question cannot be answered with a general

statement. Every case is unique: How is the structure of the existing/new building, what kind of green roof is anticipated,

what is the purpose of the green roof? Existing roofs – especially in dense urban areas – is a resource that is not fully

unlocked. The roof areas can be used wisely to enhanced the quality of the city, and if green roofs is the right solution

can only be answered individually for each case. Translating quality into financiel benefits – or the other way round – is a

very complex procedure.

3. What is the clients' opinion when suggesting the implementation of a green roof in your projects? We mainly get

very positive feedback. So far I haven’t heard of a client refusing to have a green roof, if we argue that this is the optimum

solution for the specific project.

4. It is known that Germany is the world leader in green roof technology. Do you think Denmark is following the path?

Absolutely. But again: Both clients, architects and engineers are realizing that the roof is a resource for the building

and the city – and that it should be developed to obtain the best purpose. According to context and climate the use of the

roof should be established – not on the basis of a green or non-green question.

5. Do local authorities encourage the Danish building industry include green roof technology in urban design? Yes.

Briefs are becoming more and more aware of sustainability matters, and especially green roofs are explicitly mentioned

as a possible strategy. Denmark currently has a great challenge on managing water due to climate changes, and green

roofs are often mentioned as a feature to counterbalance the changes.





Valer Daniel Rudics

Constructing Architect Student

VIA University College Aarhus

Halmstadgade 2, 8200, Aarhus Nord

School e-mail: [email protected]

Privat e-mail: [email protected]

Tlf: 27 89 73 45

Please save a tree and do not print this e-mail! J



1


From: Henrik Windbirk (HENW)

Sent: Friday, September 13, 2013 9:30 AM


Subject: SV: green roof


Hello Daniel, of course you are wellcome to mention my name in Skanderborg, but I am not sure that Hanne knows me. (I do not remember her!) I will look forrward to see some pictures from the Biennale. And now to your questions:


Well, the herbs and grass is sustainable it self, if it is not "fed" with toxic liquids. There are some materials

comming with the system, that might not be sustainable.


implement the green roof in a new building? (Could you explain your decision?) As we briefly talked about, the green roof will give a longer life to the membranes underneath it. That is benefit.

Another, an more important benefit is, that is it not necessary to enlarge til sewer-pipes in the terrain, because the

green roof delays the rainwater by heavy rain. If a city have mays squaremeters of green roof, it will help the city

to breath.

3. What is the clients' opinion when suggesting the implementation of a green roof in your projects? My former clients were all very positive, where they were explained the benefits of the green roof. An important

thing here, is that they can use is as marketing.


the path?

Yes, here in Denmark we know theat the germans are very good at this, and there are ahead of us. I hope

Denmark will follow that path. We are not there yet...

5. Do local authorities encourage the Danish building industry include green roof technology in urban

design?

I think Copenhagen encourage to "think green" using green roofs. It is not my experience with the local

authorities, I have been working with, but they like the idea.

My experience is, that the most good ideas, concerning this, comes from architects and scientists.

Money rules, you know!

Maybe, you can use my answers, otherwise, we can talk about it next time, I am in your class. Best regards and have a nice weekend Henrik WindbirkHenrik WindbirkHenrik WindbirkHenrik Windbirk Arkitekt MAA|Architect MAA

GreenStar

Typewritten Text

Enclosure 8.14.

2

Underviser|Lecturer

VIA University College

Halmstadsgade 2

DK - 8200 Aarhus N

Mail: [email protected]

Fra: Valer Daniel Rudics (178744)

Sendt: 12. september 2013 10:25

Til: Henrik Windbirk (HENW) Emne: RE: green roof

Hello Henrik,

First of all, thank you so much for the information supplied! I will try to contact the company to ask them several

questions and I will also try to write to Hanne if it is possible to visit the place one day. (Is it okay to mention you as

reference when contacting the people from the company?)

Then I want to congratulate you for the award!!!!! I am sure you are very proud to have a prize for one of your

projects!!!!! I also had a little prize back in 2010 at ‘Bucharest Architectural Biennale’ before coming to study in

Denmark. I can show some pictures next time you are coming to class. ☺

And last but not least, would you like to dedicate some time to answer few questions regarding the green roof

approach? I will put them here in the e-mail and if any of them fit to your knowledge and curiosity to answer, I would be

very grateful.






the path?

5. Do local authorities encourage the Danish building industry include green roof technology in urban

design?

Again thank you so much for everything! Speak soon!


Valer Daniel Rudics




3



Tlf: 27 89 73 45


From: Henrik Windbirk (HENW)

Sent: Thursday, September 12, 2013 8:50 AM To: Valer Daniel Rudics (178744)

Subject: SV: green roof

Hello Daniel,

I think, I can help you! The building is situated in Skanderborg and it is an activity-house for disabled people, and is it part of the buildings, that belong to "Landsbyen Sølund" in Skanderborg. Here is a link to the website: http://www.solund.dk/Guldhornet.aspx. Unfortunately the website is in danish...

I designed the building in 2008/2009, an it got an architectual prize in 2010, so it is quite new!

The company, that supplied the building with the green roof is called VegTech; www.vegtech.dk. It think it is a swedish company, but also situated in Denmark. The guys from the company, I was working with were Ulrik Reeh and Gregers S. Gregersen.

It should be no problem to visit the building, because it is situated in an public area. If you want to see it from the inside, you need to make an appointment. I think you can contact Hanne Jørgensen tlf. 8794 8190 or e-mail: [email protected] Good luck!

Bedste hilsner/Best regards

Henrik WindbirkHenrik WindbirkHenrik WindbirkHenrik Windbirk

Arkitekt MAA|Architect MAA

Underviser|Lecturer

VIA University College

Halmstadsgade 2

DK - 8200 Aarhus N

Mail: [email protected]

Fra: Valer Daniel Rudics (178744)

Sendt: 12. september 2013 06:56 Til: Henrik Windbirk (HENW)

Emne: green roof

Hello Henrik,

4

Regarding that project you mentioned the other day in class, that building that comes out of the ground the one with

the green roof. Could you possibly share a link to more information about it or maybe who was responsible for the

green roof design and implementation? I think it would be very helpful for the dissertation if I could to ask that person

several questions for empirical data, and hopefully also visit the building if that is possible. Unfortunately in Aarhus

seems like there is a lack of green roof buildings in the present, except ‘Moesgård Museum’ which is not completed yet.

Looking forward to hear from you!


Valer Daniel Rudics






Tlf: 27 89 73 45


1


From: Torben Hoffmann <[email protected]>

Sent: Wednesday, September 18, 2013 2:15 PM



Attachments: image001.png

Follow Up Flag: Follow up

Flag Status: Completed


Hi Valer Sorry for my late answer See my comment below. Med venlig hilsen/Best regards Torben Hoffmann Projektsalg

Mobile: +45 2060 8838 Email: [email protected]

Byggros A/S • Egegårdsvej 5 • DK-5260 Odense S • Tel: +45 5948 9000 • Fax: +45 5948 9005 [email protected] • www.byggros.com Company of Byggros Holding A/S


Sendt: 11. september 2013 10:13

Til: Torben Hoffmann Emne: Interview about green roofs.


green roofs influence the urban environment?' I would really appreciate if you could take some time and answer the following questions which are part of my research for the empirical data.


GreenStar

Typewritten Text

Enclosure 8.15.

2

Our Substrate I produced from old crushed bricks, sand and compost. Our drainage plates are made from recycled Ps. I know that some producers are using, systems witch are 100% degradable. But then the whole system is not function any longer after 3 – 5 years – and that’s really not sustainable ! - A green roof have to live forever, just like a biotope does in nature.


implement the green roof in a new building? (Could you explain your decision?) There is no difference ! It´s all depending on the building I selves. An old building/and even some new building does not allways have the required bearing capacity. And only the very thin solutions can be used. In that case many benefit of an green roof disappears. And also the financial benefits like water storage capacity.

3. What is the clients' opinion when suggesting the implementation of a green roof in your projects? Actually - They are always very interested, and are planning the best solutions. But in the end, the Green Roof are often the element witch are spared, wenn they have to save money, or the cheapest thin solutions are chosen.


the path? Absolutely, I even think that Denmark are going further, by solving total rainwater-solutions, where Green Roofs will play at big part.

5. Do local authorities encourage the Danish building industry include green roof technology in urban design? There are many Municipalities witch are encouraging Green Roofs in their local Building plans. Still somebody does not believe in Green Roofs !







GreenStar

Typewritten Text

Enclosure 8.16.

Valer daniel rudics green roofs dissertation_project

Education

Transcript of Valer daniel rudics green roofs dissertation_project