Methodology of integrated design of low energy office buildings

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Methodology of integrated design of low energy office buildingsMetodologi af integreret design af lavenergi kontor bygninger

Master thesis submitted in fulfilment of the terms for obtaining the degree of civil engineer-architect.

Eindwerk aangeboden tot het verkrijgen van de graad van burgerlijk ingenieur-architect.

KUL

Departement ASRO

Kasteel van Arenberg

3001 Heverlee

Belgi

DTUBYG

Department of Civil

Engineering

Lyngby

Denmark

Sarah Leenknegt

Jonas Vandermaesen

Vejleder, DTU Svend Svendsen

Promotor, KUL Staf Roels


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Preface |Page 1

Preface

This master thesis was written as part of an Erasmus exchange. In fact, the thesis

topic that was offered to us by Professor Svend Svendsen was the deciding factor to

choose Copenhagen as Erasmus destination.

DTU, the largest technical university in Denmark, has a very open and welcoming

atmosphere, with lots of international students. The Danish students from the

International Office and the Buddy organisation made sure all the international

students were properly introduced to life at DTU. But we would not even be here

without the help of the people from the International Office at our home university,especially Anouck Brouwers.

We decided separately that we wanted to do an Erasmus exchange. The country of

destination would depend on the master thesis subject, which should be related to

more energy-efficient building design. We want to thank Staf Roels, our supervisor in

Belgium, for putting us into contact with professor Svend Svendsen from DTU, who

offered us the opportunity to make a master thesis about integrated design of

buildings, which fitted our wish perfectly. Svend Svendsen was also our supervisor

throughout this project: we were always welcome with questions, and the feedback

we received was always very useful. Often, he spotted problems or errors long beforeus. Errors we were only aware of after further investigation.

This master thesis included a lot of work with unfamiliar computer programs. This

has caused us some frustration, which is inevitable, but it would have been far worse,

had we not had the assistance of some very patient people on the BYG-department:

in the first place Steffen Petersen, but also Toke Rammer Nielsen and Christian Anker

Hviid. We can promise Steffen and Christian that we finally understood the lighting

system in iDbuild.

One does not write a master thesis with professional support only. Writing a masterthesis together with another person is a challenge, the more because we didnt know

each other that well beforehand. Working together on this thesis, though, was a

blessing: there was always someone around to lend a listening ear when uncertain, to

be frustrated together about one of those incomprehensible computer outputs.

But we also have some personal thanks to make.


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Preface |Page 2

Sarah:

In the first place, I have to thank my parents, as they have given me the chance to take

part in this Erasmus-experience. But not only this: they have spent so much time

reading and correcting. My mother lifted the English language to a higher level, and my

father checked if everything was scientifically correct. Also my two sisters should be

mentioned here, even though they were far away. My elder sister Eva shared her

thesis-experience with me and helped us ahead with some basic practical things.

Without her, this preface would not exist. My younger sister Lotteke was a

continuous listening ear for my Danish experiences and was always a source of

humour and distraction. I also want to thank my parents and sister for their visits, and

in particular the several kilos chocolate they brought from home: they helped me

through some hard moments.

Two very good friends deserve a place here too: Lia and Nathalie, who were living

their own Erasmus-thesis adventure at the same time but on the other side of Europe,

could always provide me with enough stories to put my difficulties here into

perspective, and made me appreciate the organised Danish mind even more. I wish

them all the best for their own thesis projects!

Finally, but not least, there is one person that was, is and will remain very important

to me: my boyfriend Markus whom I met at DTU. He only knows a fraction of what

we were doing, but he made my stay in Denmark into a period in my life I will always

look back upon with a smile.

Jonas:

I would like to thank my parents for their support during the work and my stay in

Denmark. In more difficult periods they were always there to encourage me and give

me advice. Furthermore I want to thank my sisters, Elise and Sarah, for their

enthusiastic interest in both my work and life in Kbenhavn.

Thanks to all my friends back home for their supportive e-mails, messages, phone

calls and even visits from some of them.

My stay in Denmark wouldnt have been the same if I hadnt lived in Kampsax

kollegiet, kkken 15. I am very grateful towards all the people that I shared the

kitchen with. They have become friends and made me feel like at home here.

I would also like to thank all the friends I met at DTU. Some of them were also

working on a master thesis and we could share good and bad moments and encourage

each other. Participating in an exchange program has always been one of my dreams

and you all made it into an experience I will never forget.


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Introduction |Page 3

Introduction

This master thesis will present a method for an integrated building design process, as

well as the application of this method with the aim of achieving a rationalisation of the

building sector.

This method will be applied in the design of a low energy office building, hereby

following the different steps inherent in the method. Through this example, the

process will be illustrated, and the advantages and disadvantages of following this

process can be discussed. Finally, the followed method will be evaluated and

suggestions for improvement are made.

This proposed design method consists of a process of four steps. As for now, these

steps are not discussed, as this is done in Chapter 0. In this introduction, themotivation and purpose of this master thesis is given, as well as a short overview of

the structure.

Through this integrated design method, we wish to design an office building with a

better performance with regard to energy consumption and functional requirements,

but also do this in a more efficient way. There are multiple reasons why we think this

is an important field of research, some of which are recounted here.

Also once a building has been constructed, the use of it requires large amounts of

energy. Most of this energy is needed for heating, ventilation, cooling and lighting.Studies indicate that air-conditioning is responsible for up to 60 % of the total building

energy consumption, depending on the building type1. The energy consumption of a

building depends partly on the behaviour of its users, but the design of the building

remains the most influential factor. The designer should therefore be aware that he/she

has a major impact on the energy performance and that it is important to work on the

decrease of the energy consumption. Fossil fuels, still the most widely used energy

source today, are becoming increasingly rare and there is a need to lower emissions of

greenhouse gasses.

A sensibility for this problem is growing among the population. Governments

acknowledge that there is a need for more energy-efficient buildings and have already

introduced some measures: new energy decrees state the maximum energy

consumption for new buildings, there are additional green taxes on the use of water

and electricity and people are encouraged to invest in energy-saving interventions

through economically interesting benefits.

But not only should there be a decrease of the energy consumption due to the use of

buildings. As buildings are objects with a long lifetime, they are very valuable. A major

1Reference 9


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part of the wealth of a society is stored in its built heritage. Therefore , it is our dut y

to improve the quality of new (and old) buildings. If we build mediocre buildings, we

are creating a problem that will last for the whole lifetime of the building, commonly

about a hundred years, because it is not possible to rapidly replace buildings when

they dont perform well enough. Improving the performance will not only affect the

energy consumption, but it will also have socio-economical implications. The

Brundtland Commission stated that the definition of sustainable development is to

"meet the needs of the present without compromising the ability of future generations to

meet their own needs.

So because of the aforementioned reasons, there is a need to design more sustainable

buildings, while also considering the economical aspect. The initial cost for the

construction of the building is mostly seen as the most important cost of the building.

Often, the economical analysis does not go beyond this initial phase. However, as the

total energy consumption, and the corresponding financial cost, continues during the

whole life cycle, the economical evaluation should consider the whole life-cycle of a

building. So, in order to achieve more sustainable, but also more economical buildings,

there should be more focus on the whole life-cycle of a building, not only on the initial

phases.

In this master thesis, we will focus on an integrated design method. This method is

explained in Chapter 0 and will be used to design a type office building throughout

this thesis. By applying the method to a prototype building, we want to create a

model for other office buildings. This example should therefore be a reflection of a

general and flexible office layout. How to design such an office is discussed in detail inChapter 2.

Through this example, we will illustrate the different steps of the design process, and

comment on them in order to improve the method. It will give us a deeper

understanding of the advantages and disadvantages of following this method.

But even though the focus in this thesis is on office buildings, integrated design should

be applied in general, for every kind of program, as it is a more efficient and optimal

way of designing. This method should function as a frame in which the program of

any building can be fitted.

Finally, a short overview of the different Chapters can be given:As it is important that the reader knows and understands the different steps in the

design method, which is the main topic of this thesis, these steps are explained in

detail in Chapter 0. This Chapter also includes a short literature study and a

comparison between the traditional design process and the proposed new design

method. A part of the Danish Building Code, which will be the reference for the

evaluation of the energy performance, concludes this Chapter.

As this method will be applied to a type office building, some attention is given to

this concept. Based on a short literature study with regard to quality office design, the

room types which will be used to compose the type office building are chosen and


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motivated. This is presented in Chapter 2. With these room types, we can start with

the application of the method. This is done in Chapters 3, 5 and 6.

Chapter 3 represents the first two steps of the method: the definition of the

requirements and the generation of the space of solutions, for each room type

separately. This Chapter contains the main analysis, made with the simple computer

tool iDbuild, and results in a list of possible solutions for each room type.

The following Chapter, Chapter 4, is an extension and correction of the analysis made

in Chapter 3. In this Chapter, we can go deeper into a number of topics.

As we now have a list of possible solutions, the different rooms can be combined into

a type office building. Two proposals are made. This is done in Chapter 5, but first

a short comparison is made between the different solutions.

Finally, Chapter 6 contains the optimization: a more detailed definition and simulation

of the different systems, applied to the whole building. This optimization is made

with the use of the program IESVE. This Chapter results in the description of a low

energy type office building, with fully defined systems and controls, composed with

the rooms generated in Chapter 3. This Chapter is extended with an extra analysis

about a comparison between iDbuild and IESVE.

In the final Chapter, Chapter 7, the method and the tool iDbuild are evaluated.

Suggestions for improvement are made.


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Index |Page 6

Index

Preface _____________________________________________________________1

Introduction_________________________________________________________3

Index ______________________________________________________________6

Errata/Additions____________________________________________________10

1 EXPLANATION OF THE METHOD _______________________________11

1.1 Comparison of design processes_____________________________________111.1.1 Traditional design process ______________________________________________ 111.1.2 Integrated design process _______________________________________________ 12

1.2 Literature Study _________________________________________________13

1.3 Explanation of the method _________________________________________151.3.1 Introduction _________________________________________________________ 151.3.2 Following the method__________________________________________________ 16

1.3.2.1 Functional requirements ___________________________________________ 161.3.2.2 Setting up the space of solutions_____________________________________ 171.3.2.3 Generation of design proposals______________________________________ 181.3.2.4 Optimization analysis and decision processes __________________________ 19

1.3.3 Application of the method ______________________________________________ 19

1.4 Danish Building Code (http://www.sbi.dk/br08/7/2/4/2)_______________20Energy class 1 _______________________________________________________________ 21Energy class 2 _______________________________________________________________ 21

2 FOCUS ON OFFICE DESIGN _____________________________________23

2.1 Type office building_______________________________________________23

2.2 Literature study__________________________________________________23

2.3 Listing of room types______________________________________________262.3.1 Single office _________________________________________________________ 272.3.2 Multiple person office _________________________________________________ 272.3.3 Meeting room ________________________________________________________ 282.3.4 Open plan office ______________________________________________________ 30

2.3.5 Circulation space _____________________________________________________ 32

3 SETTING UP THE SPACE OF SOLUTIONS ________________________33

3.1 Introduction _____________________________________________________33

3.2 iDbuild [Annex 1] ________________________________________________33

3.3 Single office _____________________________________________________343.3.1 Introduction _________________________________________________________ 343.3.2 Analysis ____________________________________________________________ 35

3.3.2.1 iDbuild Systems _________________________________________________ 353.3.2.2 Defining list of systems ___________________________________________ 383.3.2.3 Motivation for season division ______________________________________ 42


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Index |Page 7

3.3.2.4 General input parameters __________________________________________ 473.3.2.5 Critical Parameters orientation independent __________________________ 483.3.2.6 Critical parameters orientation dependent ____________________________ 653.3.2.7 Conclusion _____________________________________________________ 72

3.3.3 Reference Example [Annex 2] ___________________________________________ 723.3.4 Space of Solutions ____________________________________________________ 73

3.3.4.1 South __________________________________________________________ 733.3.4.2 North __________________________________________________________ 79

3.3.5 Graphical Presentation [Annex 3] ________________________________________ 84

3.4 Multiple person office _____________________________________________853.4.1 Introduction _________________________________________________________ 853.4.2 Analysis ____________________________________________________________ 86

3.4.2.1 iDbuild Systems _________________________________________________ 863.4.2.2 General input parameters [Annex 4] __________________________________ 873.4.2.3 Critical parameters orientation independent __________________________ 873.4.2.4 Critical parameters orientation dependent [Annex 4] ___________________ 93

3.4.3 Reference Example [Annex 5] ___________________________________________ 933.4.4 Space of Solutions [Annex 6] ____________________________________________ 93

3.5 Meeting room____________________________________________________943.5.1 Introduction _________________________________________________________ 943.5.2 Analysis ____________________________________________________________ 95

3.5.2.1 iDbuild Systems _________________________________________________ 953.5.2.2 General input parameters [Annex 7] __________________________________ 973.5.2.3 Critical Parameters orientation independent __________________________ 973.5.2.4 Critical parameters orientation dependent [Annex 7] __________________ 1043.5.2.5 Conclusion ____________________________________________________ 104

3.5.3 Reference Example [Annex 8] __________________________________________ 1043.5.4 Space of solutions [Annex 9] ___________________________________________ 104

3.6 Open plan office_________________________________________________1053.6.1 Introduction ________________________________________________________ 105

3.6.2 Analysis ___________________________________________________________ 1073.6.2.1 iDbuild Systems ________________________________________________ 1073.6.2.2 General input parameters [Annex 10] ________________________________ 1083.6.2.3 Critical Parameters orientation independent [Annex 10]________________ 1083.6.2.4 Critical parameters orientation dependent [Annex 10] _________________ 108

3.6.3 Reference Example [Annex 11] _________________________________________ 1083.6.4 Space of solutions [Annex 12] __________________________________________ 108

3.7 Remarks _______________________________________________________1093.7.1 Air tightness ________________________________________________________ 1093.7.2 Cf thermal mass of the furniture _______________________________________ 1103.7.3 Extra insulation______________________________________________________ 1103.7.4 Ventilation and venting rates ___________________________________________ 112

3.7.5 Combined correction _________________________________________________ 113

4 DETAILED ANALYSIS _________________________________________114

4.1 Thermal mass detailed investigation ______________________________1144.1.1 Introduction ________________________________________________________ 1144.1.2 Comparison thermal mass wall thermal resistance _________________________ 1174.1.3 Calculation of the thermal mass _________________________________________ 1204.1.4 Heating detailed investigation with IESVE_______________________________ 125

4.1.4.1 Analysis ______________________________________________________ 1254.1.4.2 Remarks on the model used _______________________________________ 135

4.1.5 Conclusion _________________________________________________________ 137

4.2 Compactness ___________________________________________________138


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Index |Page 8

4.2.1 Investigation 1: constant building layer ___________________________________ 1394.2.2 Investigation 2: constant number of offices [Annex 13] ______________________ 145

4.3 Temperature setpoints ___________________________________________1464.3.1 Introduction ________________________________________________________ 1464.3.2 Reference room _____________________________________________________ 1474.3.3 Investigation 1: Setpoint night ventilation _________________________________ 151

4.3.3.1 Setpoint variation _______________________________________________ 1514.3.3.2 Evaluation of indoor thermal comfort________________________________ 1524.3.3.3 Warm summer week _____________________________________________ 1554.3.3.4 Cold summer week ______________________________________________ 1574.3.3.5 Conclusion ____________________________________________________ 1594.3.3.6 Temperature data [Annex 14] ______________________________________ 159

4.3.4 Investigation 2: Setpoint cooling during the day ____________________________ 1604.3.4.1 Setpoint variation _______________________________________________ 1604.3.4.2 Evaluation of indoor thermal comfort________________________________ 1604.3.4.3 Conclusion ____________________________________________________ 1634.3.4.4 Temperature data [Annex 15] ______________________________________ 163

4.4 Influence of combining interventions _______________________________1644.4.1 Introduction ________________________________________________________ 1644.4.2 Analysis ___________________________________________________________ 165

4.4.2.1 Introduction____________________________________________________ 1654.4.2.2 Influence of interventions _________________________________________ 167

4.4.3 Conclusion _________________________________________________________ 179

5 FROM ROOM TYPES TO A TYPE OFFICE FLOOR PLAN__________180

5.1 Room performance ______________________________________________1805.1.1 Introduction ________________________________________________________ 1805.1.2 Analysis ___________________________________________________________ 180

5.1.2.1 Lighting_______________________________________________________ 1815.1.2.2 Heating _______________________________________________________ 1815.1.2.3 Highest energy consumption_______________________________________ 1825.1.2.4 Functional performance __________________________________________ 183

5.1.3 Summary of all rooms energy consumption [Annex 16]_____________________ 183

5.2 To a type office floor plan_________________________________________1845.2.1 Introduction ________________________________________________________ 1845.2.2 Sections [Annex 17] __________________________________________________ 1845.2.3 Combining sections __________________________________________________ 184

5.2.3.1 Comparing sections______________________________________________ 1845.2.3.2 Combining sections______________________________________________ 1865.2.3.3 Module 12 m _________________________________________________ 1895.2.3.4 Module 13 m _________________________________________________ 191

6 OPTIMIZATION WITH IESVE __________________________________193

6.1 Introduction ____________________________________________________1936.1.1 Structure of this Chapter_______________________________________________ 1936.1.2 Review iDbuild systems and building functions ___________________________ 194

6.1.2.1 Listing of the systems ____________________________________________ 1946.1.2.2 Description of the building functions ________________________________ 1956.1.2.3 Conclusion ____________________________________________________ 196

6.1.3 User Guide IESVE [Annex 18] _________________________________________ 196

6.2 One office module _______________________________________________197

6.2.1 Pre-analysis of IESVE-systems _________________________________________ 197


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Index |Page 9

6.2.1.1 Heat exchanger _________________________________________________ 1976.2.1.2 Air handling group with heating and cooling coil_______________________ 1986.2.1.3 Air flow to the rooms ____________________________________________ 2006.2.1.4 Natural ventilation ______________________________________________ 202

6.2.2 Implementation to office module ________________________________________ 2036.2.2.1 Description of construction elements [Annex 19]_______________________ 203

6.2.2.2 Description of the systems ________________________________________ 2036.2.3 Optimization on room level ____________________________________________ 218

6.2.3.1 Evaluation of indoor thermal climate ________________________________ 2186.2.3.2 Evaluation of energy performance __________________________________ 2306.2.3.3 Final design office module_______________________________________ 236

6.2.4 Office building ______________________________________________________ 2426.2.4.1 Reference building ______________________________________________ 2426.2.4.2 Investigation: higher U-values _____________________________________ 2466.2.4.3 Investigation: lower internal gains __________________________________ 2486.2.4.4 Investigation: flexible office use____________________________________ 2496.2.4.5 Investigation: optimization artificial lighting __________________________ 250

6.2.5 Conclusion _________________________________________________________ 251

6.3 iDbuild vs. IES ____________________________________________2536.3.1 Introduction ________________________________________________________ 2536.3.2 Model _____________________________________________________________ 253

6.3.2.1 General input___________________________________________________ 2546.3.2.2 Constructions __________________________________________________ 2546.3.2.3 Glazing _______________________________________________________ 2586.3.2.4 Systems/controls ________________________________________________ 2596.3.2.5 Venting and night ventilation ______________________________________ 264

6.3.3 Comparison and results _______________________________________________ 2656.3.3.1 Comparison and results___________________________________________ 2656.3.3.2 Analysis of comparison___________________________________________ 267

6.3.4 Conclusion _________________________________________________________ 272

7 EVALUATION OF METHOD ____________________________________273

7.1 Introduction ____________________________________________________273

7.2 Evaluation _____________________________________________________2737.2.1 Methodology _______________________________________________________ 273

7.2.1.1 Setting up of requirements ________________________________________ 2737.2.1.2 Generating the space of solutions ___________________________________ 2747.2.1.3 Generation of design proposals_____________________________________ 2767.2.1.4 Optimization ___________________________________________________ 277

7.2.2 General evaluation ___________________________________________________ 2777.2.2.1 Applicability ___________________________________________________ 2777.2.2.2 Advantages and limitations________________________________________ 278

7.2.3 Improvements to method ______________________________________________ 2797.2.4 Evaluation of iDbuild _________________________________________________ 280

7.3 Final conclusion _________________________________________________282

8 REFERENCES _________________________________________________283

9 INDEX ANNEXES ______________________________________________285


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Errata/Additions |Page 10

Errata/Additions

p. 48.

The supposed error in iDbuild mentioned here is in fact not an error. The difference in

the heating load of the two simulations was due to a difference in system definition,which we overlooked when we were looking for an explanation of this difference.

p. 67.

An extra figure should have been added, to illustrate the influence of applying this

extra insulation layer. We can however refer to Figures 10 and 11 to illustrate the

influence of this extra insulation layer.

p, 69.

The daylight levels are calculated in the center of the room, at 0,8 m from the floor

(desk height). This is valid for all the iDbuild simulations, unless otherwise stated, aswas done for the open plan office.

p. 83.

The simulations for the north oriented offices indicated that we needed large window

dimensions, in order to achieve a sufficient daylight factor. This is why the north

offices have much larger windows than the south offices. However, according to the

LightCalc model, the calculation of the daylight factor is made based on the Standard

Overcast Sky model. This should mean that the daylight factor is the same for all

orientations. This error in the simulation program caused us to choose larger window

dimensions then necessary. In the mean time, this calculation error has been corrected.

p. 117

A short introduction to Chapter 4 is added here, to clarify the relevance of this

Chapter and its place in this master thesis.

In this Chapter, we have made a number of detailed investigation with regard to the

thermal behaviour of a building. These investigations are not directly related to the

method, but they allow us to have a better insight in how to design a low energy

building. We investigate the influence of the thermal mass, the compactness and the

effect of lowering passive cooling setpoints. Finally, an investigation is made to

evaluate the effect of the combination of different energy-saving interventions.

p, 189.

Some extra explanation was added to this paragraph, to clarify the followed process.


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1 Explanation of the method |Page 11

1 Explanation of the methodThe topic of this master thesis is the integrated design of buildings, with focus on a

very good energy performance. A method for integrated design is used and put to the

test as to evaluate and improve it. In this Chapter, we will describe this method anddefine the different steps in the design process to be followed. First, the traditional

design process is discussed. Why does this pose problems, and what are the relative

advantages of integrated design?

Secondly, a short literature study can be made that can give us an idea of the concept

of integrated building design, as it is most often referred to in articles. This concept

can be compared with the method that is described, applied and evaluated in this

master thesis. Finally, the method that forms the topic of this master thesis is

explained in detail.

1.1 Comparison of design processes1.1.1 Traditional design processThe design process is traditionally a top-down, sequential process: the architect

develops an overall concept and the expression, layout and organisation of the

building. In a second phase, this design goes to the structural engineers and finally the

HVAC engineers guarantee a pleasant indoor environment. There are several reasons

why this process is not efficient or logical:

First of all, there is an anomaly in the fact that current design practice starts with

developing the form of the building, while functional requirements are only solved at

the very last moment. Buildings are made to protect people from the outdoor

environment: changing temperatures, wind and rain or snow. Nevertheless, throughout

history, the main focus of builders has always been mainly on the constructive and

mechanical aspects of buildings. When people want to perform certain activities they

need a stable and comfortable environment that allows them to do so. This is the main

reason why buildings are made, so these requirements should be considered from the

first phases of the design process. Also when we have to reduce the energy

consumption for the climatization of a building, we have to design the building so it is

able to be climatized by itself, through passive rather than active techniques.

A second remark is that in the traditional design process, the different specialists

dont work simultaneously: first the architect, then the structural engineer and finally

the functional engineers. Buildings are complicated objects, and it is impossible for one

person to know everything about them. Therefore it is necessary to split up the

responsibilities. This has the advantage that people can specialise in a certain field.

The disadvantage is of course that there is a need for good communication between

these specialists. Design decisions very often affect several other decisions or

boundary conditions. If one person knew everything, he or she could consider all the

implications of decisions, and make the right choices. When the knowledge and


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expertise belongs to different people, they have to consult each other when making

decisions. When this does not happen, people will make decisions that can affect the

performance of later development phases.

If design decisions are considered separately, they might seem interesting, but they

might lose their potential when combined with others. It can also be the other way

around: some solutions might be rejected, but they might be interesting when

combined with other ones. In this case, there are two possibilities: either an iteration is

started and the previous decision is reconsidered. This will give a better product,

because several aspects will fit together better, but it will cost time, which could have

been avoided by better communication. The second option is that the previous

decision is not changed, which will save time, but the product will not be the

optimum.

A third problem, which is a more general one, is the fact that a building is always a

prototype. Optimisation of such a prototype is never attained because for each

building the architect starts from scratch. The design process is time consuming and

thus expensive, and there is no time or money left for optimization. It is of course not

possible to erect the same building over and over again because the site, the boundary

conditions, expectations of the client etc. are different every time. It is therefore

normal that the focus in the traditional design process is on specific site based design.

There should however be more attention and time for optimization, and using a type

building as a reference model could make the design process faster and more efficient.

1.1.2 Integrated design processIn this paragraph, a solution is proposed for the problems mentioned above, throughan integrated design approach. The main improvement lies in not splitting up the

design in separate phases, in which a specific part of the design is being solved, but in

considering all aspects at the same time, thereby creating an integrated design. It is still

possible and even necessary, to work from a conceptual, general idea to a more

detailed level in a number of steps. The difference is that in every step, all the

problems are solved to the degree of detail, appropriate for this level. Specifically this

means that the design is not first made by the architect, and to be calculated by

engineers later on. There will be a design team, consisting of all specialists: architects,

structural and mechanical engineers, electrical and HVAC engineers and economists

working together in close contact and sharing information and solutions all the time.The team will be coordinated by an integrated design facilitator. (Birch & Krogboe).

It is important to take into account the economical aspect, because integrated design

aims at integrating all the relevant aspects of buildings and building design, and the

financial cost is often a decisive aspect. The goal is not only to make better buildings

in terms of construction, indoor environment and energy consumption, but also to

take into consideration the economical aspects.

Because this way of designing should prevent the designers from making unnecessary

iterations, the integrated design process will be more efficient. This gives the

opportunity to investigate more possibilities in the same design period as would be

necessary when the ordinary way of designing was used.


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In the beginning of the design process, the decisions with the most impact are made. It

is important to keep open as many options as possible in this phase, and to eliminate

whichever has disadvantages afterwards. In the traditional process theres only one

solution, so we can never know if it is optimal.

1.2 Literature StudyIn relevant literature there is a general consensus that the use of integrated design can

have a high impact on the energy performance of buildings2. Integrated design has a

definite advantage over the traditional, sequential design process, because it is far more

efficient than the simple application of a series of low energy interventions.

Integrated Building Design (IBD), Integrated Design Process (IDP) or Integrated

Design Approach (IDA) are different labels that cover the following main principles,

as often stated in the definition3:

- minimizing heating and cooling loads and equipment sizeo highly insulated envelopeo high performance glazingo good architectural and lighting designs

- selecting the equipment with the highest efficiency availableOne of the largest users of energy is the HVAC system. These installations are

generally oversized, which makes them more expensive and results in a part load

operation4. By using an integrated design approach, this can be prevented: the HVAC

equipment can be designed in a more correct way and the outcome is an installationthat works at full load so the COP will be higher. This is not only interesting from an

energetic point of view; it also results in a lower initial cost due to smaller equipment

and a lower operational cost, with an immediate profit to the client.

The integrated design approach aims at helping the designer to take the right decisions,

from the beginning of the process. This way the potential of energy-saving is not lost

from the start. The decisions made at the beginning of the design process, namely

geometry, glazing surface and orientation have a very high impact on the realizable

energy performance of a building.

There are several proposals to achieve an integrated design through the use of a

computer tool5. Such a tool can act as a guide for the architect, so he can evaluate the

effect of design decisions easily. The problem with these tools is that they need a lot

of input parameters for an accurate calculation. In the initial phase, when a tool that

can give a fast indication of the energy performance of a building is most needed, very

few parameters are known. This is due to the nature of the design process, which is a

2References 4, 5 and 6

3Reference 2

4

Reference 55 References 3 and 6


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top-down process: the architect begins with a general concept for the building and

starts working on a more detailed scale afterwards. This is the reason for the lack of

known parameters values in the beginning of the process.

Another problem is that these programs are not generally implemented; they are only

used by specialised research bureaus6. There are several reasons for this, probably the

most important being that most of those programs are too complex. It is also a matter

of habits: architects are not used to making use of them in their designs and they have

no time to learn them or to adapt themselves to this way of working. A third reason is

that most actors in the design process are hardly interested in the whole life-cycle and

user costs of a building, so they dont have any interest to invest in this, neither in

time nor resources. Finally, until now, people have too few incentives to do so.

Only a minority of the architects is, at the moment, actively engaged in achieving

better performing buildings, although there are more and more large projects with

green ambitions that can serve as an example7.

The methodology of these computer tools, developed for implementation in the

beginning of the design process, is based on determining which parameters have to be

used. Defining them is interesting, as well as for computational as for

theoretical/methodological reasons. According to Shaviv8, three main parameter types

can be distinguished.

The first category consists of parameters with a strong influence on the energy

performance, but insensitive to other parameters. Examples are the internal load, the

temperature setting for heater and cooler and the suggested wall insulation.

In the second category we find parameters with a strong influence on the energyperformance, and sensitive to other parameters. These are the critical parameters. An

example of such a critical parameter is the recommended area of southern glazing: the

amount of glazing has a major effect on the solar gains, energy losses and daylight.

There is also a mutual effect of this parameter on for example the amount of insulation

in the wall, the overall percentage of glazing, relative to the total faade area, and most

importantly the orientation. A designer can choose the area of glazed surface in a

certain wall, and this will determine whether or not this wall is suitable for a south

orientation or vice versa.

Finally there are the parameters with a weak effect on the energy performance,

therefore insensitive to other design parameters. They can be set to default values andspecified later. An example is the colour of the building envelope.

From the relevant literature the following conclusions can be made. Most authors and

researchers respect the current design practice, which consists of starting with the

main concept that dictates the general form and view of the building, and working into

more and more detail as the project progresses. The problem with this practice is well

known, and was explained in paragraph 1.1.1. The solution is then sought in

6References 8, 9 and 10

7

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developing computer tools to guide the designer through the initial phases, with a

constant eye on the effect of the design decisions on the energy performance. It is

stated that the traditional design method is not likely to change drastically. The

condition that the proposed computer tools will be used is therefore related to how

well these can be integrated into the existing design practice without altering the

traditional design sequence. According to literature, few of these tools are actually

implemented by architects until now.

It is important to note that the design method that forms the subject of this master

thesis is going one step further than the integrated design process as described and

defined in literature and summarized above. It is more than lowering the loads and

using high performance equipment. The design method discussed in this master thesis

proposes a change in the traditional design order, and includes an evaluation on room

level in the first phase of the design process. In the next paragraph this design method

is described.

1.3 Explanation of the method1.3.1 IntroductionIntegrated design aims at improving the knowledge sharing between different

specialists during the design process, in order to optimize this process. Thereby

designers should be prevented from making decisions without considering the effects

of these decisions on other design fields. Primordial in this method is the cooperation

of a design team, composed of different specialists. The coordinator of this group can

either be the architect or a person called an integrated design facilitator. The mostimportant thing is that this person has sufficient knowledge about all the fields of

design (architecture, structural and mechanical engineering, electrical and HVAC

engineering, economy,) and can guarantee the integration of all disciplines. The

advantage of choosing architects is that they are most often the ones who have contact

with both the client and the engineers, and are trained in communicating with them in a

graphical way. However, if the architect has this role, it must be noted that in some

countries, like Denmark, the architecture education is primarily focussed on aesthetics

and that constructive issues receive very little attention. In this case, the architect is

not the best person to play this important role in the process. This appointment of an

integrated design facilitator to the project team is aimed at providing an independentfacilitator to guide the sustainability discussion and to negotiate and advance the

inputs of the design professionals, ensuring consistent application of objectives and

assessment criteria.9The size of this design team depends on the size of the project. For a single family

house, there is no need for a big team, but integrated design remains useful.

The proposed integrated design method focuses on lowering the energy demand of

buildings. Its purpose is to give advice to the architect, so that the right design

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decisions can be taken in the first phases of the process. To ensure this, the

traditional order of the design process is altered: in this kind of integrated design

process the design starts on the scale of individual rooms, and not on the scale of the

general layout of a building. The concept of this integrated design method is to

optimize each type of room from the building program. These rooms are the building

blocks to be used later in the composition of the building. This way, the engineers

provide the architect with the best building blocks. Note that this optimisation is not

done in separate steps, as the idea of integrated design is one of constant

communication and interaction between different specialists. A team of engineers and

architects will investigate the major options or concepts for the building services, the

construction elements and the room design. Gradually, when working into more detail,

some of the options will be ruled out, while others are retained and can be optimized.

In the following step, the architect assembles these blocks into several design

proposals. In cooperation with the team of engineers some proposals will be ruled

out. Finally, one proposal is retained and optimized. We expect that the final result

will have a better energy performance than simply stacking these blocks. The main

objective hereby is not only a good energy performance, but a well integrated design of

all the buildings functions.

The method will be demonstrated, tested and evaluated through the design of a

fictitious office building.

1.3.2 Following the methodThe method itself consists of the following four steps.

- Defining the functional requirements- Setting up the space of solutions- Generation of design proposals- Optimization analysis and decision process

1.3.2.1 Functional requirementsFirst of all, the functional requirements of the building have to be determined.

Functional requirements are boundaries for the performance decisive parameters for

the indoor environment: temperature, indoor air quality, daylight and acoustics. In the

standard, such as the Danish Building Code10

, one can find the requirements for theindoor environment for different types of rooms and buildings.

When a client wants to build, he or she wants to construct an environment to perform

activities. According to which kind of activities the building and rooms will be used

for, this environment has different specifications. The client will mainly expect that

the indoor environment will be suitable for the desired activities. However, engineers

will translate those specifications onto quantifiable parameters and limits for the

values of these parameters. It is the task of the architect or the integrated design

facilitator, to translate the demands of the client into functional requirements. These

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values can be measured, or simulations will calculate them, and they can be compared

to the standards.

1.3.2.2 Setting up the space of solutionsThe second step is the preparation of aspace of solutions.

Several proposals for rooms will be made by varying a limited set of parameters, and

their performance will be tested. These parameters are for example the geometry,

window area, type of glazing and ventilation strategy. Many parameters have effect

on several factors.

E.g., the depth of a room: a deep room will have less heat loss due to a smaller faade

area. On the other hand, the energy use for electrical lighting will be higher, because

daylight cannot penetrate deeply enough into the room, and permanent electrical

lighting will be necessary in the dark zone.

Figure 1: Deep roo m Figure 2: Undeep roo m

The purpose is to set up aspace of solutions, i.e. a range of possible solutions for the

rooms. All solutions have to comply with the requirements, but some solutions can

have a better performance. Solutions will be characterised by values for the varied

parameters and a corresponding performance.Based on the performance, different solutions can be compared and classified. An

optimal space, which takes several aspects into account, can be generated.

Nevertheless, it is possible that the parameter studies yield some options, that do not

have the required performance, listed in the previous step. These solutions indicate

what not to do. So this second step will provide the team with a set of building

blocks, classified according to their performance, which can be used to compose the

building.


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In this master thesis, the parameter variations will be made by using a computer tool,

called iDbuild11, a combination of the programs BuildingCalc and LightCalc. For a

certain set of parameters, the performance of a room type can be calculated.

The output of this step is in the first place numerical. Data about energy performance,

indoor environment quality, daylight factors are available. This detailed output is

valuable for the design team, but not for the client. Graphical output will have to be

generated to illustrate the possible solutions in a clear way. Sketches are easy to

understand and even for the designers, they can sometimes be more useful than

detailed numerical output.

Parallel to this step, it is relevant to think about quality office design.

How to provide a good working office building, with easy collaboration between

different departments? Space for single offices, group meetings, collective work,

storage and circulation has to be provided in a flexible way, so different types of

companies can work in this office layout efficiently or adjust the building easily. By

investigating this, we can decide which room types will be part of the type office.

This is discussed further in the following Chapter, and is also a preparatory phase

towards the third step of the method.

1.3.2.3 Generation of design proposalsThe third step consists of thegeneration of design proposals.

The rooms can now be combined into a layout for the building, using only those

rooms with a satisfactory performance. In every step of the method it is important for

the design team to keep as many solutions open as possible, so that several proposals

can be made. This way, solutions that might be ruled out in an earlier stage, can appearsuitable when combined with other ideas. It also guarantees that the client gets to

choose the design of his own choice, and doesnt have to choose the proposal of the

design team.

The energy performance of a building is determined by the functioning of the building

as a whole, its not only a matter of using optimized rooms. Some aspects, such as

passive ventilation, have to be developed on the scale of the building. Also the

boundary conditions, used when calculating single rooms, can be quite different from

the actual conditions when the rooms are combined in a building. They play an

important role in the realizable performance of the building. An example of such a

factor is the compactness of the building, which will be investigated in more detail inChapter 4.2.

Very rough calculations of energy performance can be made by using spreadsheets and

the data from the space of solutions, for the rooms that are used in the design

proposal and will give an idea of the overall performance of a group of rooms. For

more detailed calculations, and also for the optimization in the next step, the computer

program IESVE will be used.

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1.3.2.4 Optimization analysis and decision processesThe fourth step is optimization analysis and decision processes. As mentioned before,

the client should have the best design, not just any design which happens to meet the

demands. Very detailed calculations will be made to decide which systems should be

used and how to control them.Finally one design has to be chosen. Many possibilities have been rejected because of

economical, structural or energetic reasons, and in the last stage of the process there

might be two or three detailed proposals, with more or less equal performance. It is

now impossible to further decide which design to choose, only based on calculations

or technical arguments, so in the end the decision will depend on preferences,

architectural quality and personal taste of the client.

1.3.3 Application of the methodThroughout the thesis, the method will be used to make an integrated design of a

fictitious type office building. An investigation of quality office layouts will be made,in an attempt to design type-offices and to decide which room types are needed. The

requirements for the indoor climate will be determined, based on the function of the

rooms and the relevant standards (prEN 15251). A low energy performance, referring

to the Danish Low Energy Class 1 (as defined in paragraph 1.4), is wanted.

In the next step, the space of solutions will be set up. The rooms will be turned to

different orientations, so they can be fitted into the building in different ways. For this

example, we have investigated onlty north and south orientation.

The third step is the assembling of building. Some type-office building geometries will

be tested and classified according to their performance. All of them will serve for the

amount of people stated in the fictitious program of demands.Finally one of the tested building geometries will be chosen and this will be optimized

further. The first three steps of the method will be on a general level and with use of

iDbuild and the fourth step will be more specific and will be supported by IESVE.

By following this method one should be able to create a building in which all aspects

are taken into consideration, and the functions of which are supported by an

integrated design. The result should be a building with a better performance, designed

in a more efficient way.

Note: in this thesis the focus is on lowering the energy demand of buildings. This has

also been the primary concern while calculating and designing the building. For a real

integrated design, a team should work together. We didnt take economical, structural,electrical aspects into consideration because that didnt belong to the scope of this

thesis. It has to be stated though, that in a real life situation, it is absolutely necessary

to consider all these aspects, to fully exploit the advantages of this method of

designing.


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1.4 Danish Building Code12 (http://www.sbi.dk/br08/7/2/4/2)The content of this paragraph is the translation of the Danish Building Code. The

original Danish text is included.

To promote the development of extra energy efficient building, there are two low

Energy Classes. Low energy buildings of Class 2 have an energy performance of circa

75% of present buildings. Low energy buildings of Class 1 have an energy

consumption of circa 50%.

The application of the low Energy Classes is initially voluntary, but for the future it is

expected to form the basis for stricter energy regulations in the Building Code. The

community can already demand for a certain Energy Class, through the local plans.

To achieve this kind of energy saving, it is necessary to combine different strategies,

for example:

- reduction of cold bridges- extra insulation thicknesses in walls and use of high performance windows andcomponents

- optimal use of incident solar radiation and daylight, orientation of the buildingin relation to sun and shades

- energy efficient ventilation strategy- buffering temperature changes during the day through use of materials inside

with a high thermal capacity

It is possible to create good architecture with higher comfort and at the same time

achieve this energy saving. This implicates that the architects, early in the design

process, take into account the form related decision, that have consequences for theenergy consumption of new buildings.

For at fremme udviklingen af ekstra energieffektivt byggeri er der to

lavenergiklasser. Lavenergibygninger klasse 2 har en energiramme p

ca. 75 pct. af energirammen i tilsvarende byggeri og lavenergibygninger

klasse 1, har en energiramme p 50 pct.

Anvendelsen af lavenergiklasserne er i frste omgang frivillig, men p

sigt forventes de at danne baggrund for skrpede energibestemmelser i

bygningsreglementet. Kommunalbestyrelsen kan allerede i dag gennem

lokalplanerne fastlgge krav om lavenergiklasse 1 og 2, jf.Planloven (Bekendtgrelse nr. 813, 2007).

For at opn energibesparelser i denne strrelsesorden er det ndvendigt

at kombinere forskellige strategier, fx:

reduktion af kuldebroer ekstra isoleringstykkelse i vgge og brug af hjisolerende ruder

og komponenter

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optimal udnyttelse af solindfald og dagslys, herunder orienteringaf bygning i forhold til sol- og skyggeforhold

energieffektiv ventilation udjvning af temperaturndringer over dgnet ved brug af

materialer indendrs med hj varmekapacitet.

Det er muligt at skabe god arkitektur med get komfort og samtidig

tilgodese de energimssige sparehensyn. Det forudstter, at arkitekter

tidligt i designprocessen tager hjde for de formrelaterede dispositioner,

der har konsekvenser for energiforbruget i nybyggeriet.

Energy class 1

Offices, schools, institutes and other buildings, that are not included in 7.2.4.1, can

be classified as a low energy building class 1, if the added energy consumption for

heating, ventilation, cooling, hot water and lighting per m2 heated surface area is not

higher than 50 kWh/m2 per year, with an addition of 1100 kWh per year, divided by

the total heated surface area.

For low energy office buildings class 1 is the energy restriction:

(50 + 1100/A) kWh/m2 per year, with A as the heated surface area.

Stk. 1.Kontorer, skoler, institutioner og andre bygninger, der ikke er omfattet af

7.2.4.1, kan klassificeres som en lavenergibygning klasse 1, sfremt det

samlede behov for tilfrt energi til opvarmning, ventilation, kling, varmt

brugsvand og belysning pr. mopvarmet etageareal ikke overstiger 50

kWh/mpr. r tillagt 1100 kWh pr. r divideret med det opvarmede

etageareal.

(7.2.4.2, stk. 1)

For lavenergibygninger klasse 1 er energirammen:

(50 + 1100/A) kWh/mpr. r, hvor A er det opvarmede etageareal.

Energy class 2

Offices, schools, institutes and other buildings, that are not included in 7.2.4.1, can

be classified as a low energy building class 2, if the added energy consumption for

heating, ventilation, cooling, hot water and lighting per m2 heated surface area is not

higher than 70 kWh/m2 per year, with an addition of 1600 kWh per year, divided by

the total heated surface area.


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For low energy office buildings class 2 is the energy restriction:

(70 + 1600/A) kWh/m2 per year, with A as the heated surface area.

Stk. 2.

Kontorer, skoler, institutioner og andre bygninger, der ikke er omfattet

af 7.2.4.1 kan klassificeres som lavenergibygninger klasse 2, sfremt

behovet for tilfrt energi til opvarmning, ventilation, kling, varmt

brugsvand og belysning pr. m opvarmet etageareal ikke overstiger 70

kWh/m pr. r tillagt 1600 kWh pr. r divideret med det opvarmede

etageareal.

(7.2.4.2, stk. 2)

For lavenergibygninger klasse 2 er energirammen:

(70+ 1600/A) kWh/mpr. r, hvor A er det opvarmede etageareal.


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2 Focus on office design |Page 23

2 Focus on office designIn this Chapter, the concept of type office building is explained in more

detail. A short literature study with regard to office design is made. Thepurpose of this study is to learn about a good functional design of a such a

type office. More practically, the necessary building blocks for a typical

office department are investigated. This list of room types will be the

basis for the analysis in Chapter 3, in which the space of solutions is

generated for each room. The final aim is to design a type office

building.

2.1 Type office buildingBased on the analysis made above, we can now determine which room types are

necessary elements of a type office module. This concept was already mentionedshortly in the Introduction, but we will elaborate here.

This master thesis deals with a general design method, but this method will be applied

to the design of a type office building: a non residential building, only in use during

office hours, from approximately 8 a.m. until 5 p.m. The layout of such a building and

the spaces it consists of, are often very similar in several office buildings. We can ask

ourselves if it is possible to find the basic elements every office building is composed

of. The idea is that one can, if this is possible, think of type offices. Such a type is a

standard solution. On building level it can be the layout for an office module with a

limited number of basic office types. The result of this exercise will be a floor plan fora department of an office building, designed in a way that it can accommodate a number

of people, who are performing several kinds of office work. This floor plan should

consist of the correct building blocks, i.e. suitable room types, to accommodate the

different functions and relations between people in an office context. It should be

flexible, so that it can be adjusted easily to changing demands from the client.

The advantage of types lies in the possibility to optimise them and use for mass

production, because they are generally applicable. This is the idea of rationalisation

and industrialisation: if we find a very useful basic model, we can define a prototype

and optimise it. Construction and fabrication could then also be adjusted to thesetypes, which would result in more efficient production and construction processes:

less waste of material, more efficient use of financial means, and a faster, cleaner and

better product.

2.2 Literature studyThere have been several good researches concerning functional office design, which is a

hot topic nowadays, with fashions and trends, as well as companies spending a lot

of money on studies to determine the right office layout, in order to optimize


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productivity of the office workers. There is no doubt as to the influence of a good

office planning on productivity.

A good office design should take into account the specific working of a company, and

provide people with a space where they can work efficiently. For this thesis, some

general guidelines for a functional office design are sought. We have to determine which

room types make up the elements of a good office layout. The requirements for these

rooms have to be chosen, and based on these, a number of energetically optimal

solutions will be sought for each room type. Finally, in the last phase of the thesis,

these room types will be combined to form an office module, which encompasses the

working of a typical company department.

There is a diversity of companies that use office spaces. Four general job types can be

given13. A first is the professional, for example a contracting officer or management

consultant. Second are the engineers or technical workers. Third are the managers, and

fourth are the administrative assistants or secretaries. These different jobs have

different functional requirements. A manager needs good contact with the people

working for him, a space for meetings within the company, but also with people from

outside the company. An engineer wants a quiet workplace, for concentrated work, but

must have the opportunity to have easy communication with team members from the

same project.

All these different needs have to be accommodated in the office design. A good office

design ensures a more efficient working of the team. And not only the performance of

the workers has to be considered, but also their satisfaction about the workplace.

These two aspects are not to be seen independently from each other.

We can now go deeper into the subject of office design. In a very extensive study,peoples satisfaction and performance in a certain workspace has been investigated14.

The typical office layouts were evaluated through the workers. Everyone knows the

traditional open plan offices: a large room without dividing walls, but scattered with

single offices in the form of the well known cubicles.

The evaluation was made by asking a large number of workers what they find

important in a workplace, and how satisfied they are of their own current workplace,

with regard to those aspects. The following main points were found15. First of all, a

workplace has to provide a space for concentrated quiet work. Although the new

trends all put a major emphasis on social interactions and group work, people at the

office still spend about two thirds of their time on individual work: reading, writing,drawing, computer work, telephoning and so on. For these activities, acoustical borders

are needed. Even a manager spends one third of his time on single work.

Secondly, support for in-the-workspace interactions is wanted. This is related to the

first point. Workspaces should enable social interaction, like information sharing and

feedback. Most face-to-face interactions between workers take place in the individuals

workplace, so this is a team space as well. A good workspace design should therefore

take this into account and support in-the-workspace interactions. Regarding office

13Reference 13

14

Reference 1315 References 13 and 15


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size, this turned out to have only marginal effect on peoples performance and

satisfaction, as long as the work surface is large enough. And finally, the circulation

systems should be designed to increase the frequency of informal interactions.

Examples are cross-roads, a coffee hot-spot or places for taking a break.

With this knowledge in mind, the open-plan offices do not receive high satisfaction

from the workers. Although this layout gives a lot of opportunity for social

interaction, it makes it difficult concentrate efficiently on individual work, which was

indeed the main complaint from the workers about this layout.

New trends are the so-called non-territorial offices16 and similar to this, new

officing 17. This can be described as the use of a set of workplaces, technologies and

processes as a system of enablers to work smarter, wherever work happens. This is a

consequence of peoples changing behaviour towards offices: people generally spend

less time in the office, with as extreme example the teleworkers, who work from home.

The time that is spent at the office is then more dedicated to group work, interaction

with others and feedback. To maximize the office occupancy levels, this non-territorial

office system was developed. It consists of interchangeable and adaptable office

spaces, where employees dont own their office, but choose one of the available

workspaces.

Although there are clear advantages to this system, a more economical use of space

being only one of them, there are also some downsides. People keep their files at home,

so they do not have a good access to this background information during meetings at

the office. Neither is it easy, in such a layout, to find a place for quiet undisturbed

working. It is however a typical example of the contemporary working of an office,

and cannot be ignored, nor seen without the benefits. Adjustments can be made tomake this more efficient, for example through the introduction of some impersonal

individual cells which are open to be used by everyone when needed. These can be

permanent or with removable walls, to suite the moments need.

The question remains, which room types are a necessary part of an effective office

design? To answer this question, we refer to the following case study 18: the VTT-

building in Espo, Finland. This building was designed with special attention to

sustainability and good office design. A study was made about the inner working of a

typical department, and about the interactions between departments. Then was

decided which rooms were needed, and how they should relate to each other. In thiscase, the total surface area is 7500 square meter, with 280 employees. The function of

the building is a technical research centre. The ambitions with regard to energy are 18

kWh/m2.a for heating and 27 kWh/m2.a for electricity. But for this case study, we are

interested in the research about the principles behind a functional office layout.

As a first part of the research, the factors influencing concentration can be determined.

An obvious factor is the acoustics of ones environment. In order to maintain

16Reference 14

17

Reference 1318 Reference 15


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concentration the absence of noise is important. This refers to acoustical boundaries,

but also to the need for absorbing surfaces in a room to decrease sound reflections.

A second factor is the indoor air quality. The study also shows that peoples tolerance

in that regard is influenced by whether they have the possibility of making adjustment

by opening windows. Other factors mentioned were the opportunity to view through

windows and the possibility to maintain paper documents.

The need for concentrated work and the wish to interact with colleagues are

contradictory towards the design of an office layout, so a combined layout is needed.

Only the open plan office would not allow for the required level of concentration, as

there is too much noise and movement. But only single offices only are also not

sufficient. Places for group meetings, encounters and open conversation should be

provided, as these improve creativity.

The following conclusion for an optimal office layout was reached, including a listing

of which room types should be part of this.

A basic need is a private space for an individual. But next to that, a common space for

a team should also be provided, private with regard to other teams. This meeting room

should support information sharing, e.g. through the presence of whiteboards,

projectors and similar.

Next to these assigned spaces, flexible work spaces, including shared desks for

different kinds of activities, are an interesting feature. The previous system can be

called combi-offices, with closed spaces for concentrated working (by the individual

AND by groups) and open spaces for flexible work.

These are three room types that are needed within one department or for one specific

team. On a larger scale, there should be a common space for a group of teams, also withthe necessary equipment to improve information sharing between teams. This meeting

room is very similar to the one mentioned above, but differs by its location: not inside

one department, but as a link between them or situated in a more public part of the

building.

The circulation network that connects all these rooms is also of importance. The

layout should be designed in a way that it funnels movement rather than disperse it.

Workstations should be located near primary routes and meeting places.

An interesting remark is the effect of visual management, as a means to support

communication. For example: glass walls around single offices keep out the noise, and

allow the other people to see directly whether or not the person in the office can bedisturbed.

2.3 Listing of room typesThe following list sums up the rooms, with a short motivation for each room type that

will be part of the type office module. Suggestions are made for the interior planning

of the different rooms, illustrating the main concepts.


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2.3.1 Single officeA general conclusion from the study made above is the need for an individual space to

perform concentrated work. The size of such a room is not so important with regard to

productivity. An area of minimum 10 m2 is chosen. The size of the worktable should

however be sufficiently large. It is important that this room has place for personal

archives, and has acoustical boundaries to assure undisturbed work. Also mentioned

was a psychological advantage of the ability to open a window and have personal

control over indoor climate.

2.3.2 Multiple person officeFor some functions, it is more interesting to share an office space with more people.

Typical numbers would be 2 to 4 people in one room. To have the best approximation

between this occupancy, a room with 3 people will be used in the simulations and in

the generation of the space of solutions. Later can then be investigated further, what

the effect is of more or fewer people.It could also be interesting to have just one person in a larger office: Some functions

may require a room for individual work, but large enough to have frequent short

meetings with 2 or 3 people. This is too small a number to occupy a meeting room, but

there is nevertheless a need for holding undisturbed meetings, also without disturbing

others: a multiple person office, occupied by 2 people will be large enough to have

small meetings between 2 to 4 people, but may hereby disturb the other occupant. An

extra investigation into a large single office might therefore also be interesting.

As a basis for the space of solutions however, a multiple person office will have an

occupancy of three people. A surface area of 26 m2 will be the starting point for the

simulations.

Figure 1: Multiple person office example two persons


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Figure 2: Multiple person office example four persons

The previous figures gives suggestions for interior organisation, for two or four people.

2.3.3 Meeting roomIt is obvious that an office cannot function without one or more spaces for groupmeetings. This meeting room should be located at the focal point of a series of

individual or multiple person offices. Use of the meeting room is thereby encouraged, it

can be used spontaneously, and all files and information are nearby. Some special

attention should be given to the relation between the meeting room, the circulation and

the smaller offices. A meeting room will have all the necessary elements to improve

communication: whiteboards, projector..

The meeting room used in the simulations will allow for a full occupancy of 15 people,

on an area of about 30 m2. Typical for a meeting room is the intermittent use, which

should therefore also be reflected in the simulations.

The following figures suggest possible interior organisation of the meeting room.


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Figure 3: Meeting room exa mple 1



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2.3.4 Open plan officeAs a last room type, the open plan office will give the office module some extra

flexibility. Whereas some functions require an individual room, there are also tasks that

are performed better in an open and flexible atmosphere, with an optimal opportunityfor group work and contact with others. This is also an interesting space to take into

account the new and changing function of the office. More people work from home,

and come to the office only for contact with others, to participate in meetings or to

receive some feedback. These people do not need a personal office: such would be

uneconomical, but there should be space for them. An open plan office creates flexible

work spaces with shared desks and interchangeable work places. It is important to

note that we do not want to use the famous cubicles-system, which implies a personal,

not interchangeable workplace, hereby losing the desired flexibility. On top of that,

this cubicle-system does not provide the necessary privacy that a permanent personal

workplace requires. The following examples illustrate possible uses of the open planoffice space.


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Figure 6: Open plan office exa mple 1

Figure 6 shows the main concept for the open plan office, with a room depth of 6m.

Impersonal desks provided working space for sit down work for whoever needs it,

while higher tableaus provide space for people to stand together and discuss. Contact

between sit ting and standing people is easy. One module is singled out on the figure.

This area is 13,8 m2 and is large enough to provide sit down working space for three

persons, resulting in an average of 4,6 m2 per person.

Figure 7: Open plan office exa mple 2

Example 2 in Figure 7 illustrates the same concept, but now for a room depth of 7 m.

The higher tableaus are now separated from the sit down desks.

It is clear that it is easy to vary on this concept, to adjust it for various room depths

and situations. In this example, again a module is singled out on the figure. This area


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is 24,5 m2 and is large enough to provide sit down working space for at least 4 persons

and stand up interaction among several people, resulting in an average of 6,1 m2 per

person, if the area is only used for individual sit down work.

Because the need for isolated work still exists, even for people who only come to the

office for interaction, meetings and feedback, some separated work spaces can be

added. This are proposed as silent cells, providing room for one or two people to

work, but on a non-personal basis. They are accessible to anyone at any time. Glass

walls admit a view of the interior, what maintains the open plan feeling, while still

separating the room from the remaining area. This concept is illustrated in Figure 8.

Figure 8: Open plan office silent cells

2.3.5 Circulation spaceThis will not be a part of the space of solutions, i.e. will not be simulated to optimize

the energy performance. Nevertheless is it mentioned separately here, because it plays

a non negligible role in a smooth office working. Areas as a corridor allow for

unplanned encounters and informal interactions. They can promote social bonds,

especially if a circulation space is combined with a collection point, like a coffee

machine with space for breaks. The corridor should funnel movement, rather than

disperse it. To achieve this, the corridor should be a pleasant place, with enough light

and not too narrow. The meeting rooms should have a logical location in the whole

office plan, which is partly influenced by the design of the corridor.

Those four, or five, room types are the basis blocks of an office department.

As we have now determined the different room types, we can begin with the

application of the method. Each room will be optimized with regard to

energy performance and functional requirements. And for each one a

number of solutions will be generated, which will then be used in Chapter 5,

to compose the type office module


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3 Setting up the space of solutions |Page 33

3 Setting up the space of solutions3.1 IntroductionAn extensive analysis of a number of parameters will be made in the program iDbuild.This program was developed to calculate energy and functional performance in a

simply way, with only a limited set of design parameters. The output is mostly

graphical, to have a quick overview of the total performance of a room.

The influence of the different parameters is investigated, so they can be defined to

optimize energy performance and comply with the functional requirements. This

analysis is mainly concerned with optimizing the systems for the room.

In the Annex (2, 5, 8 and 11), a reference example of each room is presented: this gives

a detailed overview of the chosen systems, and the resulting performance.

Second, a short analysis is made to generate a list of possible solutions. This is thespace of solutions. It is on the basis of this list that the office module in

paragraph 5.2 is composed.

In Annex 3, a graphical presentation is made from the space of solutions. For this

graphical presentation, the total space of solutions is subdivided in a number of

performance groups: each room is evaluated according to energy and functional

performance. This graphical presentation is only made for the single office, to illustrate

this concept.

Before the individual rooms are discussed, an introduction to iDbuild is given, in which

the most important functions are described, as well as some more information aboutthe calculation model. This is recounted here for readers who are unfamiliar with the

program and can be found in Annex 1.

3.2 iDbuild19 [Annex 1]

19Reference 12, 18 and BuildingCalc/LightCalc User Guide

Methodology of integrated design of low energy office buildings

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