Optimized early-stage life cycle 
assessment of buildings  
Developing a tool enabling early-stage parametric 
life cycle assessment  
Master’s thesis in Industrial Ecology 

 
MARIA E. TJÄDER 
 
 
DEPARTMENT OF ARCHITECTURE AND CIVIL ENGINEERING 
DIVISION OF BUILDING TECHNOLOGY 

CHALMERS UNIVERSITY OF TECHNOLOGY 
Gothenburg, Sweden 2021 
www.chalmers.se 



  
 

  



 
 
 

MASTER’S THESIS ACEX30 

 

 

 

 

 

 

 

Optimized early-stage life cycle assessment of buildings  
Developing a tool enabling early-stage parametric life cycle assessment 

Master’s Thesis in the Master’s Programme Industrial Ecology 

MARIA E. TJÄDER 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Department of Architecture and Civil Engineering 
Division of Building Technology 

Sustainable building 
CHALMERS UNIVERSITY OF TECHNOLOGY 

Göteborg, Sweden 2021 





 
 
 

 

Optimized early-stage life cycle assessment of buildings  
Developing a tool enabling early-stage parametric life cycle assessment 
 
Master’s Thesis in the Master’s Programme Industrial Ecology 

MARIA E. TJÄDER 

 

 

© MARIA E. TJÄDER, 2021 
 
Examensarbete ACEX30 
Institutionen för arkitektur och samhällsbyggnadsteknik 
Chalmers tekniska högskola, 2021 
 
 
Department of Architecture and Civil Engineering 
Division of Building Technology  
Sustainable building 
Chalmers University of Technology 
SE-412 96 Göteborg 
Sweden  
Telephone: + 46 (0)31-772 1000 
 
 
 
 
 
 
 
 
 
 
Cover: 
Results shown in the tool. Further explanation in Chapter 6. 
Department of Architecture and Civil Engineering. 
Göteborg, Sweden, 2021 





 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 I 
  

Optimized early-stage life cycle assessment of buildings  

Developing a tool enabling early-stage parametric life cycle assessment  

Master’s thesis in the Master’s Programme Industrial Ecology 

MARIA E. TJÄDER  

 

Department of Architecture and Civil Engineering  
Division of Building Technology  
Sustainable building 
Chalmers University of Technology 

 

ABSTRACT 

In the early stages of a building project, there is low quantity and quality of data 
regarding building materials while the ability to influence the environmental 
impact is high. Easy ways of assessing environmental impact of materials in 
these stages can make a big difference and shift buildings’ contribution to global 
warming towards a more sustainable track.  
 
The aim of the thesis project was to develop a parametric tool enabling early-
stage Life Cycle Assessment (LCA) of buildings. The tool focus at guiding the user 
in lowering the embodied carbon from buildings by assessing building materials 
and building shapes. The tool also seeks to be educational about the climate 
impact from the production phase of buildings, and the intended user group is 
architects. The method of the thesis followed three steps: 

 requirement definitions based on interviews and a tool and literature 
review 

 tool development 
 case studies for validation 

 
The interviews were a crucial step to inform the later tool development and to 
make sure the tool is usable by the intended target group. From the interviews it 
was found that important features of an early-stage LCA tool are to use national, 
generic data, show the results in a visual way and make it fast and easy to use. 
Additional results from the interviews are identified industry needs and 
challenges.  
 
The case studies included user tests and numerical tests. The developed tool fills 
most criteria set by the interviewees; however, further validation of the load-
bearing concepts is asked for. The tool manages to balance a high level of detail 
and a user-friendly interface, and the calculated results are within a 15% 
accuracy. The thesis project shows that the integration of the users' needs and 
expectations from the very beginning of the development of assessment tools 
will ensure the tools’ applicability in the design process. 
 
Key words:  Life cycle assessment, early-stage design, optimization tools, climate 

impact, sustainable architectural design 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

II

Optimerad livscykelanalys av byggnader i tidiga skeden  

Utveckling av ett verktyg som möjliggör parametrisk livscykelanalys i tidiga skeden 

Examensarbete inom mastersprogrammet Industriell Ekologi 

MARIA E. TJÄDER  

 

Institutionen för arkitektur och samhällsbyggnadsteknik 
Avdelningen för Byggnadsteknologi 
Hållbart byggande  
Chalmers tekniska högskola 

 

SAMMANFATTNING 

I byggnaders tidiga designskeden är kvaliteten och kvantiteten på data kring 
byggnadens material låg men det finns en stor potential att sänka miljöpåverkan. 
Förenklade sätt att uppskatta klimatpåverkan i dessa skeden kan göra stor 
skillnad och styra byggnaders bidrag till den globala uppvärmningen i en mer 
hållbar riktning.  
 
Examensarbetets syfte var att utveckla ett parametriskt verktyg som möjliggör 
livscykelanalys (LCA) i tidiga skeden. Verktygets fokus är att leda användaren till 
sänkningar av inbyggd klimatpåverkan från byggnader genom att utvärdera 
olika byggnadsmaterial och byggnadsutformningar. Verktyget fokuserar även på 
att vara utbildande kring klimatpåverkan från produktionsfasen av byggnader 
och målgruppen är arkitekter. Examensarbetets metod följde tre steg: 

 definition av behov baserat på intervjuer samt litteratur- och 
verktygsstudier 

 verktygsutveckling  
 fallstudier för validering 

 
Intervjuer som metod påverkade utvecklingen av verktyget och säkerställde 
användbarheten för målgruppen. Från intervjuerna kom det fram att det för ett 
LCA-verktyg i tidiga skeden är viktigt att använda nationell, generisk data, visa 
resultaten på ett visuellt sätt och att verktyget är effektivt och enkelt att använda. 
Ytterligare resultat är identifierade behov och utmaningar som branschen står 
inför.  
 
Fallstudierna bestod av användartest samt numeriska test av verktyget. Det 
utvecklade verktyget uppfyller de flesta önskemålen från intervjuobjekten men 
en ytterligare validering av konstruktionstyperna önskas. Verktyget balanserar 
en hög detaljeringsgrad med en god användarvänlighet och de beräknade 
resultaten är inom en 15% felmarginal. Examensarbetet visar att om man 
integrerar användares behov och förväntningar tidigt i utvecklingen av 
analysverktyg så kan man säkra tillämpligheten i designprocessen. 
 
Nyckelord: Livscykelanalys, design i tidiga skeden, optimeringsverktyg, 

klimatpåverkan, hållbar arkitektur 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 III 
  

Contents 
ABSTRACT I 

SAMMANFATTNING II 

CONTENTS III 

PREFACE VII 

ABBREVIATIONS AND DEFINITIONS VIII 

TABLES AND FIGURES IX 

1 INTRODUCTION 1 

1.1 Background 1 

1.2 Aim 1 

1.3 Research question 2 

1.4 Delimitations 2 

1.5 Audience 2 

1.6 Outline of thesis 2 

2 THEORY 3 

2.1 Building floor area definitions 3 

2.2 Parametric design 3 

2.3 Life cycle assessment 4 
2.3.1 Goal and scope 5 
2.3.2 Inventory analysis 6 
2.3.3 Impact assessment 6 
2.3.4 Interpretation 6 

2.4 LCA in the building industry 6 

2.5 LCA in environmental certifications 8 

2.6 Climate declarations 9 

3 METHOD: LITERATURE REVIEW, INTERVIEWS AND TOOL REVIEW 14 

3.1 Literature review 15 

3.2 Interviews 15 

3.3 Tool review 16 

4 RESULTS: LITERATURE REVIEW, INTERVIEWS AND TOOL REVIEW 17 

4.1 Literature review 17 
4.1.1 Early-stage LCA 17 
4.1.2 Digital tools 19 
4.1.3 Strategies for lowered environmental impact 20 
4.1.4 Connection to part one of the research question 21 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

IV

4.2 Interviews 22 
4.2.1 The challenge of lowering climate impact 23 
4.2.2 Climate declarations 24 
4.2.3 Early-stage definition 25 
4.2.4 Reasons for conducting an early-stage LCA 28 
4.2.5 Inputs of an early-stage LCA tool 29 
4.2.6 Calculations of an early-stage LCA tool 32 
4.2.7 Outputs of an early-stage LCA tool 34 
4.2.8 Connection to part one of the research question 36 

4.3 Tool review 37 
4.3.1 Byggsektorns Miljöberäkningsverktyg (BM) 37 
4.3.2 OneClick LCA 38 
4.3.3 The Buildings and Habitats object Model (BHoM) 39 

5 METHOD: TOOL DEVELOPMENT AND CASE STUDIES 40 

5.1 Tool development 40 
5.1.1 Requirements derived from the literature review 40 
5.1.2 Requirements derived from the interviews 40 
5.1.3 Requirements derived from the tool review 42 
5.1.4 Methodological choices 43 
5.1.5 Delimitations 44 
5.1.6 3D modelling 44 
5.1.7 Environmental data assignment 46 
5.1.8 Load-bearing structures 47 
5.1.9 Visualisation of results 47 
5.1.10 The script 48 
5.1.11 Tool concept 48 

5.2 Case studies 49 
5.2.1 Korseberg strand 49 
5.2.2 User tests 49 

6 RESULTS: TOOL DEVELOPMENT AND CASE STUDIES 51 

6.1 Tool development 51 
6.1.1 3D modelling 51 
6.1.2 Environmental data assignment 51 
6.1.3 Load-bearing structures 54 
6.1.4 Visualisation of results 55 
6.1.5 The script 57 
6.1.6 Areas of usage 57 

6.2 Case studies 58 
6.2.1 Korseberg strand 58 
6.2.2 Connection to part three of the research question 61 
6.2.3 User tests 61 
6.2.4 Connection to the second research question 64 

7 DISCUSSION 65 

7.1 Literature review 65 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 V 
  

7.2 Interviews 65 

7.3 Tool review 66 

7.4 Tool development 66 

7.5 Case studies 68 

7.6 General discussion 68 

7.7 Further studies 68 

8 CONCLUSION 70 

REFERENCES 72 

APPENDIX I- INTERVIEW MATERIAL 76 

APPENDIX II- ENVIRONMENTAL DATA 77 

APPENDIX III – LOAD-BEARING STRUCTURES 83 

APPENDIX IIII- CASE STUDY DATA 85 
 

  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

VI

  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 VII 
  

 
 

Preface 
In this study, early-stage life cycle assessment (LCA) has been explored through 
interviews, tool and literature reviews, tool development and case studies. The 
work has been carried out from January to May 2021. The report is the result of a 
Master’s thesis of 30 ECTS in the Master’s programme of Industrial Ecology.  
 
The work has been conducted at the department of Architecture and Civil 
Engineering, division of Building Technology, at Chalmers University of 
Technology, Sweden with external supervision from Bengt Dahlgren AB (BDAB), 
Gothenburg, Sweden. The project has been carried out with Assistant Professor 
Alexander Hollberg and Energy and Environmental Engineer Gerda Ingelhag as 
supervisors and Full Professor Holger Wallbaum as examiner. 
 
I would thereby like to thank Alexander Hollberg for giving academic guidance 
and excellent support in the field of tool development and LCA. I would also like 
to thank Gerda Ingelhag for widening perspectives, sharing her great knowledge 
and experience, and for providing the Swedish building industry perspective on 
LCA. Further, I would like to thank Holger Wallbaum for giving valuable 
feedback.  
 
Thank you to the employees at Bengt Dahlgren AB, especially Linda Wäppling, 
Giovana Fantin Do Amaral Silva and Maria Perzon for your endless support and 
inspiration. Thank you for sharing resources and opening up your network 
enabling the interviews. 
 
Further, it should be noted that the thesis could never have been conducted 
without the rewarding meetings with the interviewees. A special thanks to 
Alexander Radne and Fraser Greenroyd for computational development advice, 
encouragement and good laughs. Thank you Martin Lindholm and Elin Lidén for 
providing a site model for the parametric modelling. 
 
Lastly, I would like to bring a special thanks to my family and friends. Thank you 
for the support and encouragement throughout my educational years at 
Chalmers University of Technology.  
 
 
Gothenburg, May 2021 
 
Maria Eleonora Tjäder 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

VIII

Abbreviations and Definitions  
Atemp   Heated building area excluding external walls  

BBR   Boverket’s Building Regulations 

BDAB   The company Bengt Dahlgren AB 

BIM   Building Information Modelling  

BM   Byggsektorns Miljöberäkningsverktyg (LCA Software) 

BOA   Building area for residential use 

Boverket   The Swedish National Board of Housing, Building and Planning 

BRA   Building area excluding external walls 

BTA   Building area including external walls 

CAD   Computer Aided Design 

CO2-eq   Carbon dioxide equivalents 

Cradle to gate  Resource extraction to finished product A1-A3 

Cradle to grave Resource extraction to end of life A1-C4 

Cradle to handover Resource extraction to construction and installation A1-A5 

Cradle to site  Resource extraction to transport to site A1-A4 

EPD   Environmental Product Declaration 

Functional unit Measure of function and provides reference flow in LCA 

GWP   Global Warming Potential 

IVL   The Swedish Environmental Research Institute 

LCA   Life Cycle Assessment 

LCC   Life Cycle Cost 

LOA   Building area for premises 

NTA   Building area excluding external and internal walls  

VPL   Visual Programming Language 

 

Life cycle phases for buildings 

A1-A3    Production 

A4-A5   Construction and installation 

B1-B7   Use  

C1-C4   End of life 

D   Benefits and loads 

 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 IX 
  

Tables and figures 
Tables and figures stated without source are made by the author of the thesis. 
 
Figure 1.  The procedure of LCA. Adapted from SIS (2006). 4 
Figure 2.  Life cycle phases. Adapted from Golsteijn (2020). 5 
Figure 3.  The LCA phases in the building industry. Adapted from SIS (2011). 7 
Figure 4.  Example of LCA calculation of climate impact. Adapted from 

Malmqvist et al. (2018). 10 
Figure 5.  The roadmap of the construction sector. Adapted from Boverket 

(2020b). 10 
Figure 6.  Planned threshold lapse. Adapted from Boverket (2020b). 11 
Figure 7.  LCA modules included in the climate declaration from 2022. Adapted 

from SIS (2011) and Boverket (2020b). 12 
Figure 8.  Proposal of LCA modules to be included in the climate declaration 

from 2027. Adapted from SIS (2011) and Boverket (2020b). 12 
Figure 9.  The methods of conducting the thesis shown on a timeline. 14 
Figure 10.  The methods and the connection to the research question. 15 
Figure 11.  LCA in the building process. Adapted from Boverket (2020a). 17 
Figure 12.  The ability to influence environmental performance through the 

building design process. Adapted from Roberts et al. (2020). 18 
Figure 13.  Distribution of professions in the interviews. 22 
Figure 14. Word cloud from interviews. 23 
Figure 15.  Definition of early stages. 26 
Figure 16.  The interviewees suggestions on when to conduct early-stage LCA. 26 
Figure 17.  User groups as stated by interviewees. 27 
Figure 18.  Priorities as stated by architects. 29 
Figure 19.  Priorities as stated by real estate developers. 30 
Figure 20. Priorities as stated by engineers. 30 
Figure 21. Priorities as stated by software developers. 31 
Figure 22. Priorities as stated by architects. 32 
Figure 23. Priorities as stated by real estate developers. 32 
Figure 24. Priorities as stated by engineers. 33 
Figure 25. Priorities as stated by software developers. 33 
Figure 26. Priorities as stated by architects. 34 
Figure 27. Priorities as stated by real estate developers. 34 
Figure 28. Priorities as stated by engineers. 35 
Figure 29. Priorities as stated by software developers. 35 
Figure 30. Result extraction from BM. 37 
Figure 31. Material input to OneClick LCA. 38 
Figure 32. Result extraction from OneClick LCA. 38 
Figure 33. Detail result extraction from OneClick LCA. 38 
Figure 34. The BHoM workflow for LCA. 39 
Figure 35.  Mean values of priorities as stated by all interviewees. 41 
Figure 36.  Geometry from a Revit model imported to Rhinoceros. 44 
Figure 37.  Geometry built in Grasshopper. 45 
Figure 38.  Load-bearing frame concepts used in the tool. Adapted from Buro 

Happold (2020). 47 
Figure 39.  Illustration of the tool functionality (version 1). 48 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

X

Figure 40. Illustration of the tool functionality (version 2). 49 
Figure 41.  3D model in the tool. 51 
Figure 42.  Functionality of importing environmental data. 52 
Figure 43. The environmental data explored in Grasshopper. 52 
Figure 44.  The choice of unit when assigning building elements. 53 
Figure 45. The choices of material category, material and thickness in the tool.

 53 
Figure 46. Background code with material build-up of pre-set material 

combinations. 53 
Figure 47. Wooden structure in the tool. 54 
Figure 48.  Steel structure in the tool. 54 
Figure 49.  Concrete structure in the tool. 54 
Figure 50.  Toggle to set building type and make visualisation choice. 55 
Figure 51.  Graph options in the tool. 56 
Figure 52. Heatmap results in the Rhinoceros view. 56 
Figure 53. Descriptions of materials in the tool. 57 
Figure 54.  Comparison of concrete and wooden floor slabs. 57 
Figure 55.  Comparison of concrete and wooden beams and columns. 58 
Figure 56. A building with a small ground floor area and ten levels. 58 
Figure 57.  A building with a large ground floor area and five levels. 58 
Figure 58.  The case study building (ETTELVA Arkitekter et al., 2020, p.4). 59 
Figure 59. The case study building and the visualised results. 59 
Figure 60.  Comparison of the calculation in BM and in the tool. 60 
Figure 61.  Percentage comparison of the results in BM and in the tool. 60 
Figure 62.  Users rating their preference of level of detail in the tool. 61 
Figure 63.  Users rating the level of 3D modelling knowledge needed to use the 

tool. 62 
Figure 64.  Users rating if the tool is fast enough. 62 
Figure 65. Users rating if the tool is transparent enough. 63 
Figure 66.  Users rating the level of LCA knowledge needed to use the tool. 63 
Figure 67.  Users rating the level of knowledge around building materials and 

structures needed to use the tool. 63 
Figure 68.  Author’s definition of when to use an early-stage LCA tool. 66 
Figure 69.  Sheet for interviewee to define early stages and when is a good time 

to use an early-stage LCA tool. 76 
Figure 70.  Sheet for interviewee to sort statements in terms of importance for 

an early-stage LCA tool. 76 
Figure 71.  Three load-bearing structures concepts (Buro Happold, 2020, p.2). 83 
Figure 72.  Detail of the concrete in the composite slab (Tata Steel, 2017, p.15).

 84 
Figure 73.  Detail of the steel in the composite slab (Tata Steel, 2017, p.15). 84 
Figure 74.  Detail of ground-to-wall connection by Integra engineering AB 

(ETTELVA Arkitekter et al., 2020, p.21). 88 
Figure 75. Detail of intermediate floor-to-wall connection by Integra 

engineering AB (ETTELVA Arkitekter et al., 2020, p.24). 88 
Figure 76.  Detail of interior wall construction by Integra engineering AB 

(ETTELVA Arkitekter et al., 2020, p.28). 88 
 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 XI 
  

Table 1. Summary of system boundaries in the Climate declaration. Adapted 
from Boverket (2020b). 11 

Table 2. LFM30’s threshold values [kg CO2-eq/ m2 light BTA/year] (IVL, 
2021). 13 

Table 3. The Finnish Ministry of Environment’s threshold values [kg CO2-eq/ 
m2 NTA/year] (Bionova Ltd, 2021). 13 

Table 4. Interviewees participating in the study. 22 
Table 5. Scheme of tool properties. 37 
Table 6. Internal wall factors. Adapted from Hollberg (2016). 46 
Table 7. Participants in the user tests. 49 
Table 8.  Selection of environmental data retrieved from Boverket (2021). 77 
Table 9.  Material amounts and environmental data from BM. Categories left 

out are marked in grey. 85 
Table 10.  Material choices and thicknesses in the Grasshopper tool. 89 
 





 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 1 
  

1 Introduction  
In this chapter the background, aim, research questions, delimitations, audience 
and outline of the thesis are presented. 
 

1.1 Background  
Society today is facing severe environmental problems that has accelerated with 
population growth and the great impact of current technologies (Hedenus et al., 
2018). Some of the challenges are climate change, chemical risks and resource 
constraints on land, materials, and energy (Baumann & Tillman, 2004). The 
building industry has a great part to play in the sustainability transition, as the 
construction and use of buildings in the EU accounts for approximately half of 
the used energy and extracted resources in the region (European Commission, 
2014). The shift from local materials with low energy costs to global materials 
like cement, aluminium, concrete, and PVC has brought high environmental 
impact (Bribián et al., 2009).  
 
Life Cycle Assessment (LCA) is a recognised methodology for assessing the 
environmental impact of products and services (Baumann & Tillman, 2004). It 
gives a holistic view of a product or service life cycle and can include the phases 
of extraction, manufacturing, use and end-of-life (SIS, 2006). LCA is used within 
the building industry and is part of environmental certifications like 
Miljöbyggnad, BREEAM and LEED (Boverket, 2019). Starting from January 1st, 
2022, climate declarations will be required for new construction in Sweden 
(Boverket, 2020b), putting the spotlight on LCA even more. 
 
The thesis focuses on assessing the climate impact of design changes in early 
project stages through LCA. In the early stages, decisions taken by designers and 
architects have a large impact on the final design of the building, while the costs 
of decisions and design effort are still very low (Li, 2017). The building’s systems 
and materials are decided in these early stages, and the choices can deeply affect 
the final climate impact. 
 
To create a design-integrated workflow a tool is developed in the thesis. The tool 
is connected to the work by Fantin do Amaral Silva & Bergel Gómez (2018) and 
Wäppling (2019) and the LCA part takes inspiration from the work by Berger-
Vieweg (2020). 
 

1.2 Aim 
The aim of the thesis is to develop a tool for early-stage LCA. The tool should be 
rooted in the Swedish building industry and seeks to encourage life cycle 
thinking in early-stage building design by exploring its application and 
variations. The tool should focus at guiding the user in lowering the embodied 
carbon from buildings by assessing building materials and building shapes. The 
tool also seeks to be educational about the climate impact of the production 
phase of buildings, and the intended user group will be specified from the 
interview results. 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

2

The developed tool aims to inform the designer of potential effects of decisions 
and hence give the user the freedom to focus on conceptual design in early 
stages. The tool is developed in Grasshopper which is a Visual Programming 
Language (VPL) plug-in within the Computer Aided Design (CAD) software 
Rhinoceros. 
 

1.3 Research question 
Below, the research question is presented. 

 How can design-integrated early-stage tools based on LCA be applied to 
increase the understanding of and help decrease the climate impact from 
the production phase of buildings?  

o [part 1] What is required… 
…in terms of input data and results? 
…in terms of transparency?  
…in terms of connection to a 3D model? 
…in terms of calculation speed?  
…in terms of software skills and LCA experience of 
the user? 

o [part 2] Does the developed tool fulfil the above-mentioned 
requirements?  

o [part 3] Are the LCA results from the developed tool within a 15% 
accuracy? 

 

1.4 Delimitations 
From interviews with stakeholders, the development of the tool will be 
narrowed down to focus on few, specific users. LCA specific delimitations are 
presented in section 5.1.5. 
 

1.5 Audience 
The targeted audience of the thesis is architects, sustainability and building 
technology engineers, real estate developers and software developers. The 
audience is also the research field of LCA and sustainable building design.  
 

1.6 Outline of thesis  
The thesis report consists of 8 chapters. The first chapter holds the introduction, 
and the second chapter provides theory on building floor area definitions, 
parametric design, LCA and its connection to the building industry, 
environmental certifications and climate declarations. Chapter 3 introduces the 
method of research for the literature review, the interviews and the tool review 
and chapter 4 the results of them. Chapter 5 introduces the method of research 
for the tool development and the case studies, influenced by the results in 
chapter 4. Chapter 6 presents the results of the tool development and case 
studies. The discussion is presented in chapter 7 and, finally, conclusions are 
made in chapter 8.   



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 3 
  

2 Theory  
The theory chapter gives a brief overview of floor area definitions, parametric 
design and introduces LCA and its connection to the building industry. The 
chapter also handles how LCA is accounted for in environmental certifications 
and the upcoming Swedish climate declarations. 
 

2.1 Building floor area definitions 
There are several building floor area definitions in Sweden, and they are used in 
different ways in LCA calculations. Some of them will be presented in this 
section.   
 
Bruttoarea (BTA) is the area of spaces measured from the outside of the external 
walls (SIS, 2005). It includes all floor levels, the attic and the basement. Area 
covered by e.g. internal walls, stairs and ramps are included. Floor slab openings 
without stairs and ramps are not included. 
 
Nettoarea (NTA) is the area of spaces measured from the inside of adjacent 
building elements (SIS, 1989) and hence it is an addition of all spaces in a 
building without the internal walls.  
 
Bruksarea (BRA) is the area of spaces measured from the inside of the external 
walls (SIS, 2005). It includes all floor levels, the attic and the basement. Area 
covered by e.g. internal walls thinner than 0.3m and stairs and ramps are 
included. Shafts thicker than 0.3m are not included, if not directly connected to a 
wall. BRA can be divided into Biarea (BIA), Boarea (BOA), Lokalarea (LOA) and 
Övrig area (ÖVA).   
 
BOA is the area of a building that is meant for residential use (SIS, 2005). LOA is 
the area for garage, business, staff rooms and stairs and ramps within the 
apartment. 
 
Atemp is the area of spaces measured from the inside of the external walls 
(Boverket, n.d.). The spaces included must be intended to be heated more than 
10°C, and it includes all floor levels, the attic and the basement if heated. Area 
covered by e.g. internal walls and stairs is included while built-in garages are not 
included. 
 

2.2 Parametric design  
In conventional design, values defining the design are fixed (Graciano, 2020). In 
parametric design however, chosen values are rather defined by parameters 
enabling variable and dynamic inputs. One or several values are assigned to each 
parameter, affecting the output. More parameters make a greater number of 
possible solutions. The applications of parametric tools in architecture are 
within simulations, automation, optimizations and digital fabrication, to name a 
few (Radziszewski & Cudzik, 2019). The use of parametric design is further 
described in the citation below.  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

4

Designers have begun using parametric design software, which allows them 
to specify relationships among various parameters of their design model. 
The advantage of such an approach is that a designer can then change only 
a few parameters and the remainder of the model can react and update 
accordingly (Jabi, 2013, p. 9-11). 

 
Rhinoceros is a 3D modelling software that can create, edit, analyse, document, 
render, animate, and translate different types of geometry with high complexity 
(Rhino3D, 2021). Grasshopper is a graphical algorithm editor integrated with 
Rhinoceros (Grasshopper3D, 2021). It allows designers to build form generators, 
but it does not require programming or scripting knowledge.  
 
The programming language C# is an object-oriented and type-safe language 
(Microsoft, 2021). It enables users to build applications running in the .NET 
ecosystem. Visual studio is an integrated development environment which is a 
workspace for editing, debugging and building code (Microsoft 2019). The code 
can be written in C# and components built in Visual studio can be used in 
Grasshopper. 
 
The master theses by Fantin do Amaral Silva & Bergel Gómez (2018), Wäppling 
(2019) and Berger-Vieweg (2020) include parametric tool development in 
Grasshopper. It has served as an inspiration for the tool development in this 
thesis. The work by Fantin do Amaral Silva & Bergel Gómez (2018), Wäppling 
(2019) has resulted in a BeDOT – a tool for early-stage energy calculation and 
daylight analysis. 
 

2.3 Life cycle assessment 
LCA assesses the environmental impact of a product or service across its life 
cycle (SIS, 2006) . The standard ISO 14040 sets the principles and framework for 
LCA whereas ISO 14044 provides requirements for conducting the assessment. 
Applications of LCA are decision making (e.g. for policy instruments), 
learning/exploration (e.g. identification of improvements) and communication 
(e.g. labelling and environmental product declarations). The assessment is 
divided in four steps: Goal and scope definition, Inventory analysis, Impact 
assessment and Interpretation as shown in Figure 1. 

 

Figure 1.  The procedure of LCA. Adapted from SIS (2006). 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 5 
  

2.3.1 Goal and scope 

The product to be studied and the purpose of the study are decided in the goal 
and scope definition (Baumann & Tillman, 2004). Specifications as functional 
unit, system boundaries, environmental impacts considered, and level of detail 
are set. The functional unit expresses the function in quantitative terms and 
makes the study comparable to other studies. Examples of functional units for 
different products and services are presented below.  
 
Product/service  Functional unit 
Wallpaper/paint  m2 and year 
Passenger transportation person and km 
Light bulbs   specified lux and year (use time) 
Building   m2 heated area and year 
 
The system boundaries specify the boundaries in relation to natural systems, 
technical systems, geography and time. Boundaries to the natural and technical 
systems are set by specifying which life cycle phases to be studied (Figure 2) and 
how to handle allocation. The environmental impacts to be studied are decided 
in the goal and scope and they are divided into impact categories. Examples of 
impact categories are land use, global warming, eutrophication, and acidification.  

 

Figure 2.  Life cycle phases. Adapted from Golsteijn (2020). 

In the goal and scope, one also defines whether the study is attributional or 
consequential (Baumann & Tillman, 2004). An attributional LCA looks at 
questions like “What environmental impact can be associated with this product?” 
while a consequential LCA looks at “What would happen if…?”. The different 
types affect system boundaries, allocation, choice of data and system subdivision. 
 
  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

6

2.3.2 Inventory analysis 

The inventory analysis consists of the construction of a flow model, data 
collection and calculation (Baumann & Tillman, 2004). The flow model holds 
activities like production, processing, transport, use and waste management and 
the flows between the activities. The data collection consists of collecting 
information of what goes into the system such as resources in the form of e.g. 
materials, water and energy. The data collection also handles emissions and solid 
waste that leaves the system and goes into air, ground and water. The calculation 
part looks at what enters the system (e.g. mineral use) and what leaves the 
system (e.g. pollutant emissions) in relation to the functional unit.  
 

2.3.3 Impact assessment 

The impact assessment connects the inventory results to the chosen impact 
categories (Baumann & Tillman, 2004). The process consists of the mandatory 
steps of classification and characterisation and the optional step of weighting. 
The classification classifies what inventory results contributes to what impact 
categories. Characterisation looks at the relative contribution to the impacts and 
aggregates e.g. the emissions to one indicator. An example of characterisation is 
the contribution of methane (CH4) and Carbon dioxide (CO2) to the impact 
category global warming. The contribution of 1kg CH4 is about 50 times higher 
than the contribution of 1 kg CO2, if looking at 20 years of global warming. To be 
able to compare different product’s contributions to global warming, the 
different trace gases are measured in kg CO2-eq. 1kg CH4 gives 56 kg CO2-eq and 
1kg CO2 gives 1 kg CO2- eq. To aggregate the impact assessment even further, 
weighting can be done. Weighting puts the impact categories on the same 
yardstick and hence it introduces a subjective judgement. It makes products 
comparable with a one-dimensional index by summarising the impact categories. 
 

2.3.4 Interpretation  

Interpretation is a way of making sense of the results, to make comparisons and 
to draw conclusions (Baumann & Tillman, 2004). Identifications of significant 
issues and evaluation through e.g. completeness and consistency checks are 
made. 
  

2.4 LCA in the building industry  
Environmental product declaration (EPD) is a standardised environmental 
market communication report and provides a specific format for the LCA 
information (Baumann & Tillman, 2004). In the Swedish building industry, the 
EPDs follow the standard SS-EN 15804 (Boverket, 2020b). LCAs in the building 
industry tend to focus on the impact category global warming and it is the 
category studied in the upcoming climate declarations in Sweden. The functional 
unit is often m2 heated area and year (Sweden Green Building Council, 2017; 
Boverket, 2020b). Figure 3 illustrates how the LCA phases in Figure 2 are 
translated into building specific phases when applying LCA in the building 
industry.  
 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 7 
  

Looking at the whole life cycle from resource extraction (module A1) to end of 
life (phase C) is called a cradle-to-grave study while looking at resource 
extraction to finished product (module A3) is called a cradle-to-gate study (Fan & 
Fu, 2017). Studying module A1-A4 is called cradle-to-site while module A1-A5 is 
called cradle-to-handover (Malmqvist et al., 2018). Benefits and loads beyond 
the system boundary are included in phase D, where circularity can be studied 
(Boverket, 2020b). For example, the impact of energy recovery from wood as a 
fuel replacing a fossil fuel can be studied in module D. Carbon emissions from 
different phases is sometimes referred to as embodied carbon and operational 
carbon (Rodrigo et al., 2019). Embodied carbon considers emissions from the 
production phase (A) while operational carbon handle emissions in the use 
phase (B). 

 

Figure 3.  The LCA phases in the building industry. Adapted from SIS (2011). 

A reference study period needs to be set for calculating environmental impacts of 
the use phase of the building (Boverket, 2020b). The calculations are made for 
the set period; however, it is not to be mixed up with expected technical life 
length of the building. As buildings have long life length compared to many other 
consumer products, scenarios describing a distant future need to be set. LCAs for 
buildings are often not considering dynamic building properties (Su et al., 2017). 
Dynamic building properties are identified as technological progress, variation in 
occupancy behaviour, dynamic characteristic factors and dynamic weighting 
factors. The accuracy of results can be greatly influenced by such factors, as the 
life cycle of a building is long. 
 
The Paris Agreement states that there is a need for negative carbon emissions, to 
reach the climate targets (Erlandsson et al., 2018). For the building industry, 
carbon sinks (e.g. bio-based materials) and carbonation of concrete are examples 
of processes achieving negative emissions.  The bio-based materials wood, hemp, 
and straw contain around 50% carbon by dry mass (Hoxha et al., 2020). The 
building materials as a carbon sink is a great possibility for carbon reductions, 
but it is important that calculations are transparent and comparable to avoid 
misleading information.  
 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

8

Bribián et al. (2009) identify drivers for using LCA in the building sector to be 
loans and subsidies from environmental impact reduction, environmental targets 
and labelling, marketing, and simplified data acquisition. Barriers identified are 
weak links to energy certification applications, lack of legal requirements, poor 
knowledge of LCA and environmental impact, inconsistent applications, 
prejudice about complexity, accuracy and arbitrary results, low demand, costs, 
complicated calculations, poor cooperation between manufacturers and 
customers, and a lack of standardised interfaces. Socio-economic costs of 
emitting greenhouse gases are according to Trafikverket (2019) 7SEK/kg CO2-
eq. The report handles the use of environmental policy instruments in the 
transport sector to hinder emissions and achieve socio-economic benefits. The 
policy instrument “climate declaration” of buildings is described in 2.6 below. 
 

2.5 LCA in environmental certifications 
There are several optional environmental certifications for buildings in Sweden 
(Boverket, 2019). A simplified LCA for building elements is included in the 
Swedish certification Miljöbyggnad (MB) while a more comprehensive LCA is 
fostered in the international certifications Building Research Establishment 
Environmental Assessment Method (BREEAM) and Leadership in Energy and 
Environmental Design (LEED).  
 
MB has 15 indicators where one of them focuses on LCA of the foundation and 
the load-bearing system (Boverket, 2019). The analysis is limited to the A1-A3 
modules to get the bronze score and A1-A4 to get silver and gold scores. It looks 
at global warming 100 years (Sweden Green Building Council, 2017). To get 
silver or gold level, EPDs holding specific data are needed (50% and 70% of the 
data for silver and gold respectively). For the gold level, a 10% lower global 
warming result compared to the silver calculation needs to be achieved.  
 
BREEAM looks at the building parts roof, windows, exterior walls, and floor slabs 
(Boverket, 2019; Sweden Green Building Council, 2018). Three impact categories 
must be studied, where global warming must be one of them. An early-stage LCA 
must be conducted, and points are given if improvements are shown throughout 
later stages.  
 
LEED studies the foundation, the load-bearing system, and the climate shell 
(Boverket, 2019). The phases encouraged are A-D and hence it is a cradle to 
grave study (U.S Green Building Council, 2020). However, points can be gathered 
if looking at a limited set of phases as well. As in BREEAM, early-stage LCA 
should be reported and a lowered environmental impact throughout the project 
stages must be shown (Boverket, 2020b). The impact categories studied are 
Global Warming Potential (GWP), depletion of the stratospheric ozone layer, 
acidification of land and water sources, eutrophication, formation of 
tropospheric ozone and depletion of non-renewable energy resources (U.S Green 
Building Council, 2020). A decrease of 10% must be shown in 3 out of the 6 
categories, where one of them must be global warming (Boverket, 2019). The use 
of local materials can give extra credits and re-using of existing materials is 
encouraged (U.S Green Building Council, 2020). 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 9 
  

2.6 Climate declarations 
The Swedish government has put in a legislative proposal of mandatory climate 
declarations, starting from January 1st, 2022 (Boverket, 2020b). The proposal 
states that a climate declaration should be conducted when applying for a 
building permit. The legislative proposal builds on the European standard SS-EN 
15978 of declaration of environmental performance of buildings and the purpose 
is to increase knowledge in the field and decrease climate impact.   
 
The climate impact in the declaration should have the functional unit kg CO2-
eq/m2 BTA and the LCA type is attributional (Boverket, 2020b). The reference 
study period is proposed to be 50 years which is analogous with the period 
chosen by several Nordic and European countries. The 50-year period is in line 
with a thought need of comprehensive refurbishment after that time. A fear is 
that such a short reference period might disfavour the use of products with long 
life cycles, but it is argued that this consequence is rarely seen in studied cases. 
Having a longer period on the other hand, creates a contingency as scenarios are 
hard to predict due to changes in future production methods. Increased 
efficiency in manufacturing and the energy mix shifting to more renewable 
energy will probably affect the scenarios (Su et al., 2017). Background emission 
concentrations influence the level of impact of the emissions (Collinge et al., 
2013) and as the concentrations might vary in a future point of time, it affects the 
scenarios.  
 
The Swedish government will hold a database of generic environmental data to 
be used for climate declarations (Boverket, 2020b). The product data and energy 
mix are representative for Swedish conditions. The data is put higher by a factor 
of 25% in the database to make incentives for using EPDs of specific products 
instead of the generic data. To make informed choices, the project developer 
needs specific environmental information of the products on the market. 
However, the developer has no right to claim it from the producers in today’s 
situation. The EU commission has decided and pushed on a framework for 
describing building products’ environmental impact. The standard SS-EN 15804 
has been developed to bring forward EPDs for building products. A legal 
connection between an EPD according to SS-EN 15804 and the harmonised 
building product standards is not set. This is one of the reasons that the 
government will hold the database of environmental data.  
 
Installations accounts for a considerable part of a buildings’ climate impact, 
around 18-46% (Boverket, 2020b). But they are often ignored in LCA 
calculations as data is missing. Installations are not a part of LCA in 
environmental certifications (Boverket, 2019). By 2027, installations will be 
included in the declarations as data is believed to be compiled and accessible 
(Boverket, 2020b). It is also thought that digitalisation is more developed at that 
time, enabling more comparable and precise calculations including additional 
building parts. Generic data for additional building parts as well as standard 
values for interior claddings and room elements should be made available in the 
database by 2027. Data for biogenic carbon of wooden based products and 
standard values for deconstruction and demolition (C1) and transport in the 
end-of-life module (C2) need to be compiled and made available. 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

10

The production phase (A1-A3) and the operational energy use (B6) have the 
highest climate impact of a building’s life cycle (Boverket, 2020b). An example of 
a relation between the different phases is shown in the LCA results of a multi-
residential building (Figure 4). The modules to be included in the 2022 
declaration are the construction modules (A1-A5) in order to focus on the 
greenhouse gas emissions occurring today. One reason for the limited number of 
modules is to be able to evaluate effects and consequences gradually. Another 
reason is that it is possible to verify the emissions and impacts of today, but it is 
harder to verify future emissions and impacts. The limited number of phases 
steers towards interventions for reducing climate impact of the A1-A5 modules. 
There is however a risk of sub optimizing if lowering emissions in these phases 
and letting higher emissions pass in later phases. 

 

Figure 4.  Example of LCA calculation of climate impact. Adapted from Malmqvist 
et al. (2018). 

The construction sector works towards a net-zero impact, in line with the 
national climate target of 2045 (Boverket, 2020b). The roadmap of the 
construction sector is shown in Figure 5. This national target states that Sweden 
should have net zero greenhouse gas emissions into the atmosphere by 2045 and 
it sets out the Swedish implementation of the Paris Agreement (Ministry of the 
Environment and Energy, 2018).  

 

Figure 5.  The roadmap of the construction sector. Adapted from Boverket (2020b). 

 
 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 11 
  

Benchmarking is important in the field to steer the industry towards a lower 
climate impact (Boverket, 2020b). From 2027, threshold limit values are 
suggested to be introduced and additional LCA modules to be included. The 
threshold limit values are proposed to be sharpened year 2035 and yet 
sharpened year 2043 as illustrated in Figure 6. The thresholds will be 
differentiated for premises, detached/semi-detached houses and multi-
residential buildings. The differentiation of buildings is analogous with the 
energy demands of Boverket’s Building Regulations (BBR). In 2027, the 
threshold refers to reference buildings. When calculating results for reference 
buildings, it will be beneficial to provide additional properties of the buildings. 
Additional properties include describing the relation between areas of different 
use (e.g. office, apartment), the relation between BTA and Atemp, the form factor, 
the floor to ceiling height and the climate zone. 

 

Figure 6.  Planned threshold lapse. Adapted from Boverket (2020b).  

As the construction of buildings has a high climate impact, a more rapid 
transition towards low emissions is needed (Boverket, 2020b). Legislations such 
as the climate declaration are needed to influence the construction stages. Table 
1 summarises the system boundaries of the climate declaration and Figure 7 and 
Figure 8 illustrates the LCA modules included. 

Table 1. Summary of system boundaries in the Climate declaration. Adapted from 
Boverket (2020b). 

Year 2022 2027 
Threshold limit 
value 

No threshold Threshold that covers 
A1–A5 

Modules to be 
included 

A1–A5 A1–A5, B2, B4, B6, C1–4, 
Additional environmental 
information,  
biogenic carbon storage, 
net export of locally 
produced electricity 

Parts of building to 
be included 

 Load-bearing elements 
 Building envelope 
 Interior walls 
 

 Load-bearing 
elements 

 Building envelope 
 Interior walls 
 Installations 
 Interior claddings 
 Room elements 

Reference study 
period 

- 50 years 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

12

 
Figure 7.  LCA modules included in the climate declaration from 2022. Adapted 

from SIS (2011) and Boverket (2020b). 

 

Figure 8.  Proposal of LCA modules to be included in the climate declaration from 
2027. Adapted from SIS (2011) and Boverket (2020b). 

Predicted consequences of climate declarations according to building firms are 
increased transparency in the sector, speeded up innovation of sustainable 
materials, higher demands on producers in terms of transparency and 
sustainability, higher apartment costs and updated frameworks of procurement 
and land allocation that takes emissions into account (Boverket, 2020b). 
According to the same report, there is a belief that architects will not be highly 
affected by the declarations until 2035, when the threshold limit values are 
sharpened. Then it will affect the design at a larger extent as it must meet the 
demands of low climate impact. Architects will need to get the competence of 
climate calculations. 
 
Despite the absence of threshold values in the climate declaration until 2027, 
several initiatives have developed their own values. LFM30 uses the EN 15978 
standard (IVL, 2021) and their threshold values presented are shown in Table 2. 
The Finnish Ministry of Environment has also set threshold values and they are 
presented in Table 3. It should be noted that LFM30 has BTA in their functional 
unit, whereas the Finnish Ministry of Environment uses NTA which is closer to 
Atemp that will be used in the Swedish climate declarations.   
 
  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 13 
  

Table 2. LFM30’s threshold values [kg CO2-eq/ m2 light BTA/year] (IVL, 2021). 

 Premises Multi-residential Small houses 
A1-A5 270 216 171 

Table 3. The Finnish Ministry of Environment’s threshold values [kg CO2-eq/ m2 

NTA/year] (Bionova Ltd, 2021). 

 Residential Office Service School Commercial 
A1-A3 282 259 282 255 215 
A4 10,2 10,2 10,2 10,2 10,2 
A5 27,3 27,3 27,3 27,3 27,3 
Total 319,5 296,5 319,5 292,5 252,5 

 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

14

3 Method: Literature review, interviews and tool 
review 

The methods of the thesis consisted of literature review, interviews, tool review, 
tool development and case studies. They were all qualitative except one of the 
case studies that was quantitative and handled numerical comparisons. The first 
three methods are described in this chapter, and a method timeline is shown in 
Figure 9. The tool development and case studies are further described in chapter 
5. The reason for splitting the method chapters in two is that the method of tool 
development and case studies are influenced by the results from the first three 
methods. 

 

Figure 9.  The methods of conducting the thesis shown on a timeline. 

The literature and tool review were made in order to put the project in a context, 
map existing knowledge and to identify how the project contributes to new 
knowledge. The literature review brought knowledge to ask relevant questions 
in the interviews. The interviews were made to get the industry perspective of 
early-stage LCA, and the tool review was made to bring inspiration for tool 
development paths. The literature review, interviews and tool review together 
fed into the tool development. The tool development was the main part of the 
thesis project, with the aim of encouraging life cycle thinking in early-stage 
building design. The first case study tested the numerical results of the tool. The 
second case study strived to see if the outcome of the development is of use to 
the stakeholders. 
 
The overarching research question was “How can design-integrated early-stage 
tools based on LCA be applied to increase the understanding of and help 
decrease the climate impact from the production phase of buildings?”. Part one 
of the research question, “What is required in terms of input data and results, 
transparency, connection to a 3D model, calculation speed, software skills and 
LCA experience of the user?”, was answered through the literature review, the 
interviews and the tool review. 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 15 
  

Part two of the research question, “Does the developed tool fulfil the above-
mentioned requirements?”, was answered by the tool development and the user 
tests in the second case study. The numerical case study strived to answer part 3 
of the research question; “Are the LCA results from the developed tool within a 
15% accuracy?”. Figure 10 illustrates the connection between the methods and 
their connections to the research question.  

 

Figure 10.  The methods and the connection to the research question. 

 

3.1 Literature review 
The literature review handled early-stage LCA, digital tools and strategies for 
lowered environmental impact. The review consisted of literature from the 
databases Google Scholar, ResearchGate and Svenska Byggbranschens 
Utvecklingsfond (SBUF) as well as other relevant reports and books. Key words 
searched for were “(LCA OR life cycle assessment AND Early-stage OR Simplified 
OR Simplification)” and “(LCA OR life cycle assessment OR building AND digital 
OR parametric OR optimization OR tool)” and “(building AND environment OR 
environmental impact OR climate OR climate impact)”. 

 

3.2 Interviews 
Interviews with architects, real estate developers, sustainability and building 
technology engineers and software developers were made to understand what 
the early-stage workflows look like and the needs of support. The workshop 
material used in the interviews is found in Appendix I- Interview material. There 
were 20 interviewees asked to participate in the interviews. The interviews were 
conducted as online meetings due to the prevailing Covid-19 pandemic. 
 
 
 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

16

The interview questions for architects, real estate developers and engineers are 
stated below. Question 1-3 were asked to get company-specific perspectives on 
climate impact and climate declarations. Figure 69 in Appendix I- Interview 
material was used to define early stages and question 4-6 aimed to understand 
workflows in those stages. Question 7-8 were asked to get their view on how, 
when and why to use an LCA-tool for early stages, as well as what are important 
features in such a tool (Figure 70 in Appendix I- Interview material).  
 

1. What project types is [the company] mainly working with? 
2. From your position, what is the biggest challenge in lowering the climate 

impact from new construction? 
3. What is your view on the upcoming climate declarations? [For Swedish 

interviewees] 
 

4. How do you define early stages?  
5. Which software is used for modelling in early stages? (E.g. Revit, Archicad, 

Sketchup, Rhinoceros, Autocad)  
6. When is the construction type, materials and geometry defined?  

 
7. How and when could an LCA tool be useful? 
8. If you would use an LCA tool, for what reason would it be? (E.g. To make a 

baseline for later stages or to use for climate declarations and 
certifications) 
 

The interview themes for software developers are stated below. They were 
chosen to get ideas of the development. The software developers also got to use 
the workshop material presented in Figure 70 in Appendix I- Interview material. 

1. Usability and adaptability of tools 
2. Inputs: geometry and environmental data 
3. Outputs: visualisations and results extraction 

 

3.3 Tool review 
In the tool review, LCA tools were studied based on their connection to a 3D 
model, environmental data handling, reference study period, impact categories, 
LCA modules and whether it is an online/desktop/plug-in tool. The tools studied 
are stated below. 

 Byggsektorns Miljöberäkningsverktyg (BM) 
 OneClick LCA  
 The Buildings and Habitats object Model (BHoM) 

 
The reason for choosing BM and OneClick LCA was that they are used in Sweden 
(IVL, 2021; OneClick LCA, 2021) and the reason for choosing BHoM was to study 
a tool that can be used in the Grasshopper environment (BHoM, 2020).  The tool 
review influenced and inspired the tool development. 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 17 
  

4 Results: Literature review, interviews and tool 
review 

The results from the literature review, the interviews and the tool review are 
presented in this chapter. By the end of the literature review and the interview 
parts, a connection to part 1 of the research question will be made. 
 

4.1 Literature review 
Below follows the literature review of early-stage LCA, digital tools and, lastly, 
strategies for lowered environmental impact. Around 20 papers were found and 
read, and the most interesting contributions are brought forward to the review. 
 

4.1.1 Early-stage LCA 

LCA in the building industry of today is often applied at late stages and hence it is 
not used to improve the building design, but rather being descriptive (Röck et al., 
2018). Applying LCA in early building design can have different purposes and be 
focused on different stages (Bribián et al., 2009). A purpose for architects is 
comparing design options in early sketching and collaborating with engineers in 
detail design. The design options compared are geometry and technical choices. 
Property developers and consultants use it in preliminary stages. Property 
developers have the purpose of choosing building sites, sizing projects and 
setting environmental targets. Consultants’ purposes are setting targets at 
municipal level and for development areas and defining suitable zones for 
buildings. Figure 11 illustrates when Boverket recommends conducting LCAs 
throughout the building process. 

 

Figure 11.  LCA in the building process. Adapted from Boverket (2020a). 

 
The application of LCA in the building sector are by some doomed to fail by being 
too complex and difficult and hence simplification is needed (Soust-Verdaguer et 
al., 2016). A strategy for simplification regarding system boundaries is to reduce 
the amount of data and optimize data collection. Simplifying the functional unit 
can refer to looking at parts of the building (e.g. focusing on 1m2 of window area) 
instead of looking at the whole building (e.g. 1 m2 of usable floor area). Other 
studies are trying to find correlating environmental impact categories (Röck et 
al., 2018). 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

18

Quantifying building materials and energy use requires a lot of time (Bribián et 
al., 2009). As engineers and architects have a short amount of time to perform 
LCA, simplified applications with appropriate interfaces can be useful. Building 
Information Modelling (BIM) is a good way for quantifying materials (Soust-
Verdaguer et al., 2016). Bribián et al. (2009) suggest handling geometry by 
extracting surface layers from the architectural model and multiplying with the 
thicknesses. Using the density, the final inventory data is the weight of each of 
the materials.  
 
In early stages of building projects, it is hard to know accurately what building 
materials and products will be used (Boverket, 2020b). Therefore, it is suitable 
to use generic data in the LCA calculation. Figure 12 illustrates the ability to 
influence environmental performance throughout the building design process.  

 

Figure 12.  The ability to influence environmental performance through the building 
design process. Adapted from Roberts et al. (2020). 

Building processes like transport, maintenance, repair, refurbishments, 
demolition, waste treatment or recycling are complex to model and are often 
simplified by referring to previous studies or regional data sources (Soust-
Verdaguer et al., 2016). Bribián et al. (2009) and Soust-Verdaguer et al. (2016) 
suggests only including the A1-A3 and B6 modules in simplified LCAs. 
Loads and benefits in phase D are hardly considered (Soust-Verdaguer et al., 
2016).  
 
For a simplified tool, project input data must be easy to find, and the impact 
categories chosen must be simple making architects, engineers and users 
understand the results (Bribián et al., 2009). Examples of well-known categories 
are water use, embodied energy, embodied carbon and waste generation, in 
contrast to e.g. eutrophication. Impact categories can be cut down by criteria 
such as regional representativeness, global impact, embodied versus operational 
impact, renewable versus non-renewable energy consumption in several cases 
(Soust-Verdaguer et al., 2016). It reduces the complexity and amount of data 
without modifying the comparability of the results. GWP is recognised globally to 
be the most significant indicator for climate change mitigation strategies. 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 19 
  

4.1.2 Digital tools 

Environmental data and LCA within the building industry are being digitalised, 
however the active users are cutting edge firms, while small and medium-sized 
firms lack resources and knowledge to use the digital tools (Boverket, 2020b). 
This brings obstacles to the information flows in the building process. Smaller 
companies that are not specialised in wooden construction are more worried 
about the legislative proposal that will come into force in January 2022, than 
larger companies and companies specialised in wooden construction, according 
to an interview study.  
 
Digitalisation is a pre-requisite to bring out high-quality climate declarations 
made in a resource-efficient way (Boverket, 2020b). However, the building 
sector is not keeping up with other sectors with regards to digitalisation. 
Research that contributes to the digitalisation in the building industry should be 
supported by the government. The government does not intend to regulate 
which tools that can be used for climate calculations. The demand of digital tools 
will increase along with increased digital information. In 2027, when additional 
building parts will be added to the climate declarations, thousands of data items 
may occur, making a manual calculation hard to conduct. Building Information 
Modelling (BIM) is believed to have a leading role in calculation and modelling of 
climate impact from buildings, from early stages to finished product. Open, 
standardised formats for transferring information between platforms and tools 
are important parts of the digitalisation. 
 
Roberts et al. (2020) studies the use of LCA throughout the design process by 
connecting it to the Royal Institute of British Architects (RIBA) plan of work. 
Most papers in the study were focusing on the LCA-BIM integration, the LCA-Life 
Cycle Cost (LCC) connection and environmentally led parametric design. There 
are challenges if undertaking LCA before BIM in projects. However, parametric 
led design can provide guidance in early stages and include different design 
alternatives from the conceptual design. Before parametric design tools and 
algorithms can hit the industry, the tools require more work, regionalisation, and 
verification. To ensure that LCA is used to its full potential, the stage of design 
must be considered. If implementing studies after the design concept is set, the 
assessment become reactive and responding to the design. Proactive results on 
the other hand have more potential to influence the design, making it possible to 
lower the environmental impact. Visual scripting interfaces like Dynamo and 
Grasshopper are encouraged in early-stage LCA and could support the 
connection to other types of analysis at different phases (Röck et al., 2018). 
 
If looking at only parts of the life cycle, there is a risk of sub optimization, meaning 
that while the analysed phases are optimized, it might affect excluded phases in a 
negative way (Boverket, 2020b). An example of sub optimization is seen 
regarding energy certifications, that usually do not cover the whole life cycle 
(Bribián et al., 2009). A good energy classification might be produced while 
bringing a higher total energy consumption by lacking a holistic view.  
 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

20

Designers need more early-stage contextual information to make early-stage 
choices and develop the concept (Roberts et al., 2020). LCA and environmental 
assessments are not integrated in the design process, it is more considered as 
additional aspects. Things that are standing in the way for adoption of widescale 
design process LCA are accessibility of detailed information, time requirements 
and the appropriateness of early-stage tools. In addition, small firms and small to 
medium-sized projects might not have resources to employ LCA expertise. Even 
though LCAs in early stages can be used to make informed decisions, it will not 
replace detailed LCAs at the point of completion.  
 

4.1.3 Strategies for lowered environmental impact 

Bribián et al. (2009) propose to promote renewable energy while also 
emphasizing bioclimatic eco-design, bioconstruction and the use of local, low 
impact, natural and recyclable materials. Operational measures like water 
consumption minimisation by designing rainwater collection systems, grey 
water networks in buildings and the design of green roofs should be encouraged. 
 
Recycling materials can lower life cycle energy by 30% and greenhouse gas 
emissions by 18% (Bribián et al., 2009). Looking at steel and aluminium, the 
embodied energy saving can be 50%. This brings arguments for the potential of 
recycled building materials to play a role in the reduction of environmental 
impact. 
 
Erlandsson et al. (2018) have summarised strategies for a lowered climate 
impact, looking at a residential case study. The strategies are to 

 use climate-improved concrete, 
 prioritise sustainable choices for materials used to a high degree, 
 use renewable fuels for transports,  
 optimize the energy use on the site, 
 choose low impact coating for balconies regarding maintenance, 
 calculate climate impact for every single project, and 
 increase the knowledge about climate impact in the entire value-chain, 

especially in the purchasing department.  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 21 
  

4.1.4 Connection to part one of the research question 

The connection of the literature review to part one of the research question is 
presented below. 

 
What is required… 
…in terms of input data and results? 
Quantities and quality of data is low in early stages. To conduct early-
stage LCA, the assessment must be simplified. Reducing the amount of 
data and optimizing data collection as well as simplifying the functional 
unit is recommended. Using BIM and generic data should be emphasized, 
and the risk of sub optimization should be kept in mind.  

 
…in terms of transparency?  
Understandable methodological choices, e.g. well-known impact 
categories should be set. The use of open, standardised formats calls for 
transparency. 

 
…in terms of connection to a 3D model? 
Multiple papers suggest BIM connections which leads to the connection to 
a 3D model. One paper recommends extracting surface layers from an 
architectural model. Parametric design is proposed as a way to provide 
guidance in early stages while studying different design alternatives. 

 
…in terms of calculation speed?  
The short amount of time to perform LCA and also the lack of resources 
points at the need of a high calculation speed. 

 
…in terms of software skills and LCA experience of the user? 
Most papers state that simplification is needed. To make assessments 
possible to conduct for someone with low LCA experience, the impact 
categories chosen must be well-known. Multiple paper points at the 
advancement of digitalization. Small and medium-sized firms might that 
lack resources and knowledge to use the digital tools and hence they 
should not be too complex.  

 
 
  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

22

4.2 Interviews 
Out of 20 people asked, 17 people participated in the interview sessions. The 
interviewees are presented in Table 4 and the distribution of professions is 
shown in Figure 13. In the following text, the interviewees are categorized into 
architects, engineers, real estate developers and software developers. 

Table 4. Interviewees participating in the study. 

Category of 
company 

Company Profession Interviewee 

Architect EttElva Arkitekter Sustainability manager 
Architect 

Emma Östlund 
Erik Björnhage 

Architect Liljewall Arkitekter Architect Alexander Gösta 

Architect  White Arkitekter Energy and environmental 
engineer  

Carl Molander 

Architect Wingårdhs Arkitektkontor Architect Vera Matsdotter 

Architect ÅWL Arkitekter Architect, BIM manager Camilla Berggren-
Tarrodi 

Engineer Buro Happold  
(Sustainability & Physics 
team) 

Associate sustainability 
director 
Graduate sustainability 
engineer 

Ben Richardson 
Loic Weisser 

Engineer eTool Life Cycle Design Sustainability consultant Marios Tsikos 

Real estate developer Catena fastigheter Sustainability strategist Anna Wallander 

Real estate developer Hemsö fastighets AB Real estate developer Emma Karlsson 

Real estate developer Riksbyggen Sustainability manager Karolina Brick 

Real estate developer Västfastigheter Sustainability strategist Mikaela Lenz 

Real estate developer Älvstranden Utveckling Sustainability manager Christine Olofsson 

Software developer Buro Happold  
(Computational team) 

Software development lead 
Computational designer 

Fraser Greenroyd 
Michael Hoehn 

Software developer StruSoft AB Computational designer Alexander Radne 

 

Figure 13.  Distribution of professions in the interviews. 

 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 23 
  

All interviewees are positive towards an early-stage LCA tool; however, the 
preferred functionalities differ a lot between and within professions. Some of the 
interviewees have great LCA experience while for others it is a completely new 
subject. Several of the interviewees have experience from developing early-stage 
and LCA tools. Figure 14 shows some of the most common words used in the 
interviews. The size of the words displays the frequency of use in the 
conversations. Words like “LCA”, “early” and “tool” has been removed. The word 
cloud shows the variety of thoughts around early-stage LCA and how to mitigate 
climate change within the building industry.  

 

Figure 14. Word cloud from interviews. 

 

4.2.1 The challenge of lowering climate impact  

Discussing the climate impact from new construction, an urban developer stated 
that “the worst thing we can do is to build new constructions, but at the same 
time we have homelessness and want the city to grow. How can we solve that 
equation in the best possible way?” (Olofsson, C., interview on February 5th, 
2021). The main challenges of lowering the climate impact from new 
construction stated by the interviewees are  

 long building processes,  
 traditional patterns of building processes,  
 lack of knowledge and 
 lack of time. 

 
As the building processes are long, the projects change a lot along the way and 
many actors are involved. Another challenge is that the industry is stuck in 
current business models. Regarding technology, there is a tendency to avoid new 
things. There are also many factors in building processes besides climate impact 
like energy, fire safety and insurances. An architect stated that they are trying to 
find project specific solutions as challenges differ in each project. 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

24

Buildings carry large material quantities which induce a high climate impact. But 
the large quantities create a great potential to make a difference. Architects and 
real estate developers mentioned the difficulty of convincing clients to use wood 
and other materials considered sustainable. One of the architecture offices has 
introduced a policy to suggest wood structures in every project as a starting 
point. An architect within another firm mentioned that comparing concrete and 
wood is like comparing apples and oranges, and that the cost of wood structures 
always will be higher. Another architect stated that they have been building a lot 
with wood and have examples showing that it does not have to be more 
expensive. Other aspects when considering wood structures are higher floor 
slabs and thicker walls, which might not be feasible in the detailed development 
plan. A real estate developer said that wooden structures hinder the flexibility of 
adding heavy equipment to their spaces in the future. Another real estate 
developer working both with new construction and maintenance, mentioned 
that there is a balancing act between demands in different phases when 
considering building materials. 
 
Several of the interviewees point at a knowledge gap, and that they need to 
investigate the climate impact of standard buildings to set targets. The lack of 
time and hence the difficulty of investigating materials was brought up as a 
challenge. As a consultant, one must be prepared to propose solutions. The 
strategy of one of the architecture firms is to have environmental consultants 
involved in all steps of the process and raise the overall sustainability knowledge 
among consultants.  
 
There were also hopeful thoughts raised. There has been a shift in interest of 
sustainable building over the past years. The clients today look for architects 
with environmental design knowledge. This used to be a non-question. Several of 
the interviewees talked about their involvement in initiatives like LFM30 and 
Fossilfritt Sverige. There is a paradigm shift in the architecture profession. The 
way the industry has worked with sustainability until now is by adjusting 
existing models and processes. When starting to talk about reuse and circularity, 
there is a change in the core processes. An architect stated that the most 
sustainable building is the one that is not built at all and hence reused materials 
has great potential. The focus on reused materials must be defined at an early 
stage. Several of the interviewees stated that sustainability must be a natural 
part in early stages, regardless of the client and the project. 
 

4.2.2 Climate declarations  

When asking about the interviewees’ views on the upcoming Swedish climate 
declarations, the answers were overall positive but most of them thought that 
the declarations are not strict enough. An architect compared the climate 
declarations with the energy and daylight regulations of buildings. He said that 
those regulations were hard to conduct in the beginning, but now it is a natural 
part of the projects. In a similar way, he thought that the climate declarations will 
be conducted naturally once people know the requirements and that it will have 
a great impact.  
 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 25 
  

Regarding preparations, the interviewees stated that they are preparing for the 
climate declarations in different ways. Some mentioned that they are working 
with BIM modelling, some are outsourcing the calculations, and others are 
investigating differences between embodied carbon calculations in MB and 
climate declarations.  
 
Several interviewees brought up that the declarations must be easy and cheap to 
conduct, but at the same time not leaving out elements. An interviewee thought 
that there is a possibility to be creative regarding what must be declared in the 
declaration and that there is nothing hindering from showing even more 
sustainability features as a way of marketing. Two of the interviewees think that 
pressure will be put on contractors and that there will be a rise in EPDs 
produced. A real estate developer hopes to see pioneering actors leading the 
way, showing that lowering the climate impact is possible and that unsustainable 
actors will be excluded. There was a general thought that the climate 
declarations will increase the environmental awareness in the industry. 
 
Critique brought up was the focus on the product phase and the absence of 
threshold values. However, the operational phase was mentioned to be covered 
by the energy declaration. Regarding threshold values, an interviewee suggested 
that a high threshold value could be set from the start, and then at least the worst 
actors would have to change. A real estate developer said that they are not 
affected by the absence of a threshold, as they can set their own targets. It was 
generally expressed that coming up with their own threshold values is hard as 
LCA calculations is something new and information is hard to find. Some think 
that the learning period for climate declarations, until 2027, is too extensive, and 
others think that it is probably needed. It was expressed that the development of 
tools will go fast and the ones running the development will probably think that 
the climate declaration demands are quite weak and strive to widen the scope.  
 

4.2.3 Early-stage definition 

When asked about the definition of early stages, the professions clearly pointed 
at different time spans in the building process. Most interviewees think that early 
stages lay in the “investigation” and “program and project definition” stages. 
Some think it starts prior to the investigation stage and one of the interviewees 
thinks that it runs until the procurement stage. There was a statement that early 
stages are ended when it is hard to propose new ideas. An architect mentioned 
that in later stages, there is a lock-in of choices. Another architect talked about 
their office as a creative and artistic workplace that enable testing things until 
late stages. Figure 15 illustrates the interviewees definitions of early stages.  
 
 
 
 
 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

26

 

Figure 15.  Definition of early stages. 

The architects talked about different ways of working in early stages: sketching 
by hand, in Rhinoceros, in Sketchup or simplified modelling in Archicad. In later 
stages, they are using BIM modelling in Revit or Archicad. An interviewee stated 
that architects do not have a lot of spare time and therefore it is hard to 
introduce new ways of working in early stages. It is hard to make a really good 
tool and a lot of testing is needed. The amount of time available in early stages 
depend on the project. Residential projects are pressed on time. As stated by an 
architect “The best thing would be to include all consultants in early stages! That 
is why indicative tools play a role, even if the accuracy is within 10-15%” (Gösta, 
A., interview on February 9th, 2021). Another architect talked about making 
isolated LCAs, for example on the facade or on the structure as it has high impact. 
If the calculation includes all building elements, it might delay the project too 
much.  
 
On the question of when to make the early LCA calculations, the answers were 
wide-spread but most of them pointed at investigations and the program and 
project definition stage (Figure 16). Some thought that as soon as there is a box 
model, it is possible to start looking into climate impact. An argument was that 
investment decisions are taken when working with rough box models and hence 
it is important to take sustainability into account.  

 

Figure 16.  The interviewees suggestions on when to conduct early-stage LCA. 

 
 



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 27 
  

When to set materials and geometry varies between projects and sometimes it 
depends on the site. There are different experiences considering the possibility 
to conduct an LCA around the program stage. An architect acknowledged that 
some big building developers have strict processes and hence the end of the 
program is really detailed. For others it can be less strict, and one might use box 
models halfway through the program. A real estate developer said that early 
calculations must be done from an architects’ drawings as structural engineers 
and other consultants are not involved in the program stage. 
 
An engineer expressed that there is no point in having the tool early on, as one 
needs a few options to appraise and an architect said that it can be done 
whenever, until the building permit is made. The real estate developer putting 
the dotted lines in every stage (Figure 16) had the argument that it is interesting 
to follow up the calculations. By the last stage, one knows what actual products 
are used. A general positive comment on the early-stage tool from a real estate 
developer was that “It would be good if we as clients were better at demanding 
and promoting that we think it is important to conduct LCA calculations in the 
early stages” (Karlsson, E., interview on February 15th, 2021). 
 
Figure 17 illustrates the ideas of user groups of an early-stage tool among 
interviewees. A software developer told to focus the user group on where the 
largest impact can be made which tend to be real estate developers, as they can 
make a great impact with a whole masterplan. Most real estate developers 
thought they would probably not use the tool themselves as they are not working 
with 3D models. Architects thought that they will make simplified LCA but that 
engineers will probably make the final climate declaration calculations. An 
engineer said that architects would probably use it rather than sustainability 
consultants. Sustainability consultants join at a later stage and by that time not 
much can be changed as there is a lot of time and money invested in the 
drawings. Another engineer thought they could use it themselves in 
competitions. 

 

Figure 17.  User groups as stated by interviewees. 

A challenge was formulated as: “An assessment at an early-stage is as accurate as 
the information that you have got in an early stage, which is not accurate” 
(Tsikos, M., interview on February 5th, 2021). Many expressed the importance of 
using generic data as you do not know exactly what products to use in early 
stages. The geometry might not be in place, neither the demands on materials. 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

28

An engineer thought that load-bearing elements could benefit from being 
standardised per m2 Atemp. Another engineer mentioned that material 
quantities for foundation and load-bearing elements changes based on the 
environment and the ground conditions, which can be interesting to study in a 
tool.  
 
Both engineers and software developers distinguished between material and 
element take-off when making an LCA tool, where material take-off is looking at 
e.g. insulation, structure and cladding separately in a wall and element take-off is 
providing a number of climate impact for a standard wall. Some engineers 
thought that an element take-off might be useful in early stages. 
 

4.2.4 Reasons for conducting an early-stage LCA 

When asked about reasons for conducting an LCA at an early stage, the 
interviewees gave various responses including to 

 provide reference values, 
 compare designs, 
 learn, 
 convince others, 
 show ambition and 
 for economic reasons. 

 
A reference value is a baseline for later stages of the project or for upcoming 
projects. With a baseline, the impact of design changes along the process can be 
tracked. An interviewee expressed that if there was a tool for simplified LCA 
available they could use it on their old buildings to get reference values. Other 
reasons mentioned were making sustainable choices, stepping away from 
standard materials and comparing different phases. An engineer thought that 
providing quick answers to these questions would be a successful feature for a 
consultant. Another engineer thought it would be an interesting selling point for 
them to use the tool in competitions, where one must keep down costs and hence 
work efficiently. Other reasons are target setting and identifying easy winners in 
terms of strategies. 
 
The learning part was mentioned as seeing consequences of choices made and 
increase the awareness. It was stated that it is beneficial to have a calculated 
number when entering an argument, especially if there are a lot of aspects to 
consider.  The number could be used to convince the project team or the 
investor. As change is costly, one must motivate the investments. Continuing the 
economic terms, an idea lifted was that early-stage LCA calculations can help 
justify loans. As costs are calculated early in the projects, sustainability targets 
need to be set for them to be considered in the budget. 
 
  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 29 
  

4.2.5 Inputs of an early-stage LCA tool 

In the following figures, mean values are marked with clear colours, and 
boundaries are set around values that are closely connected .Figure 18 shows 
architects’ values regarding inputs.  

 

 
Figure 18.  Priorities as stated by architects.  

Opinions raised around the statements in Figure 18 are listed below.  
 It is important to use national environmental data. 
 Adding EPDs is not relevant in early stages as one does not know what 

actual products will be used. 
 It seems hard to include reused materials in LCA today, but it would be 

nice to show if a product is reusable and if it stores CO2. 
 

All architects think that a connection to a 3D model is important (Figure 18). It 
gives a connection to the actual project rather than just comparing materials. As 
almost all projects are made in 3D models today, there is a wish to have a 
running connection between the LCA calculation and the project’s 3D model. The 
architects had different preferences on ways of modelling. Common arguments 
for staying in their modelling environment were to 

 have a smooth workflow, 
 avoid licences, 
 not having to learn a new software, 
 save time and 
 view the material changes directly in the model. 

 
Linking to Archicad was important for several architects while Sketchup and 
Rhinoceros was preferred by others. Some expressed that people think 
Grasshopper is hard to understand and that it is not suitable as a modelling 
environment. They acknowledged that the industry will be more digitalised and 
in a couple of years there will be a more parametric view where data informs the 
design. “LCA calculations is a staggering new subject. A lot of people are working 
on it and I think it is only the beginning. The tools developed today is only the 
first iteration of upcoming, more comprehensive tools” (Molander, C., interview 
on February 5th, 2021).  
 
  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

30

Figure 19 shows real estate developers’ values regarding inputs. 

 

 
Figure 19.  Priorities as stated by real estate developers.  

Opinions raised around the statements in Figure 19 are listed below.  
 The possibility to add EPDs and reused materials is more important at 

later stages and hence it can be left out in this tool.  
 Even if most real estate developers interviewed are not working with 3D 

models, some saw the relevance of a connection to 3D models. One of 
them thought that they are not going to conduct the calculations 
themselves but rather have consultants like architects and structural 
engineers do it.  

 To not make calculations of all building elements in every project but 
instead utilise similarities in projects. There might be strategies that can 
be applied in all projects, and it is important to think of what is generic 
and what is project specific. Money should be put where it really makes a 
change.  

 

Figure 20 shows engineers’ values regarding inputs. 

 

 
Figure 20. Priorities as stated by engineers. 

Opinions raised around the statements in Figure 20 are listed below.  
 It is important to use a qualitative and representative set of EPDs and it 

would be good to make it easy to input EPDs. Another engineer expressed 
that EPDs mostly refer to specific products and hence it is not appropriate 
for early stages. 

 It would be interesting to see the climate impact of re-used materials at 
an early stage.  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 31 
  

 Regarding the statements “no modelling experience” and “connection to a 
3D model”, it points at different tools. In a similar way, “model from Revit” 
and “model by parameters” could be two different tools.  

 An engineer working with tool development mentioned that when 
developing the tool, one should not presuppose a box model and hence 
manage advanced geometry from the start.  
 

An engineer expressed that using a Revit connection would be future proof as 
architects will probably use Revit increasingly. Revit is also suitable for pulling 
quantities in a quick manner. Connection to an existing model will keep more 
details while reconstructing the model probably will be hard unless you are just 
looking for rough calculations. On the other hand, reconstructing the model 
could be good if you want to use it as an optioneering tool and quickly change the 
design. It could be a different tool, or a different branch of the tool, for different 
stages. The likelihood of having multiple Revit models produced by the architects 
is low. The end goal of using the tool defines what model should be used. The 
engineers were united that a high level of modelling experience should not be 
required (Figure 20). 

 

Figure 21 shows software developers’ values regarding inputs. 

 

 
Figure 21. Priorities as stated by software developers.  

Opinions raised around the statements in Figure 21 are listed below.  
 If the tool is to be adapted to make further analysis, U-values and fire 

properties could be added. 
 Some of the software developers highlighted that it is crucial to have a 

connection to a 3D model, but that it is important to be flexible in how you 
build the model. However, the modelling by parameters had low priority 
(Figure 21). 

 The ability to influence the results by iterations and optimizations was 
discussed. An example is that a change in slab thickness changes the 
column placement and therefore it affects the material use in two ways.  

 An idea raised by a software developer was to have an iterative process 
enabling optimization of design based on previous outputs. 

 

  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

32

4.2.6 Calculations of an early-stage LCA tool 

Figure 22 shows architects’ values regarding calculations.  

 

 
Figure 22. Priorities as stated by architects. 

Opinions raised by architects around calculations and the workflow are listed 
below.  

 The tool must give instant feedback. 
 Transparency is important to most architects, as it is key to understand 

what might have gone wrong. An argument against transparency is that 
some architects do not want to be showered with technical information 
and numbers, but rather just trust the results.  

 Deep LCA experience should not be required, however if it is an advanced 
tool with a lot of settings, prior knowledge of LCA is needed.  

 
Figure 23 shows real estate developers’ values regarding calculation. 

 

 
Figure 23. Priorities as stated by real estate developers.  

Opinions raised by real estate developers around calculations and the workflow 
are listed below.  

 The tool should be fast and enable quick testing of different material 
combinations and designs.  

 Previous LCA experience is needed for the tool users.  
 Keep processes simple.  
 It is important that the tool is cost effective to not conduct expensive 

investigations in every project.  
 Make it possible to follow up results along the way. 

 

  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 33 
  

Figure 24 shows engineers’ values regarding calculation. 

 

 
Figure 24. Priorities as stated by engineers.  

Opinions raised by engineers around calculations and the workflow are listed 
below.  

 The need for transparency depends on the user and is different depending 
on if it is an engineer or architect. Transparency is more important when 
going to later stages.  

 Early-stage tools risk to focus too much on details. The tool cannot be too 
basic either, as it would not provide any information then. 

 

Figure 25 shows software developers’ values regarding calculation. 

 

 
Figure 25. Priorities as stated by software developers.  

Opinions raised by software developers around calculations and the workflow 
are listed below.  

 There is a dislike of tools that are “black boxes” with no transparency, 
especially if the users have limited LCA experience.  

 One of the software developers argued for simplicity and that it should be 
easy to redo the visual coding script. The same interviewee points out 
that using a single component to perform a lot of calculations could make 
it hard for someone else to understand how it works. 

 From a computational viewpoint, the reliability of the tool is essential. If 
the tool often crashes, users will doubt other functions in the tool as well. 

 

  



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

34

4.2.7 Outputs of an early-stage LCA tool 

Figure 26 shows architects’ values regarding outputs.  

 

Figure 26. Priorities as stated by architects. 

Opinions raised by architects around outputs are listed below.  
 Precise calculations are not important in early stages. 
 The connection to certifications is rather a question of formatting the 

results than a crucial tool development issue. 
 The focus should be on global warming to begin with. 
 To look into economic costs of materials in the calculation. 
 Focus on analysing the load-bearing structures. 
 Emphasize on communicative, pedagogical visualisations.  

 
Figure 27 shows real estate developers’ values regarding outputs. 

 

Figure 27. Priorities as stated by real estate developers.  

Opinions raised by real estate developers around outputs are listed below.  
 Precise results are not important, but different tools must show similar 

results.  
 A connection to certifications could be relevant in the program stage but 

probably not in the detailed development plan stage.  
 Regarding additional impact categories, a real estate developer stated that 

“It is important to include multiple impact categories and we must be able 
to keep multiple things in mind, by not only focusing on climate impact” 
(Brick, K., interview on February 19th, 2021). 

 To compare results with legislative thresholds.  
 To keep the same system boundaries as in the climate declaration.  
 To look into economic costs of materials in the calculation. 

 

  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 35 
  

Figure 28 shows engineers’ values regarding outputs. 

 

Figure 28. Priorities as stated by engineers.  

Opinions raised by engineers around outputs are listed below. 
 Showing transports might be misleading, as it is not the major impact.  
 Regarding visualisations, it would be helpful to show a heatmap in the 

Rhinoceros model and a citation was that “It is good to show the result in 
the form of architecture!” (Richardson, B., interview on February 9th, 
2021). Everything is visual at those stages and hence it is good to 
emphasize on visualisations.  

 
Figure 29 shows software developers’ values regarding outputs. 

 

Figure 29. Priorities as stated by software developers.  

Opinions raised by software developers around outputs are listed below. 
 One software developer stated that precise results are more important 

than fast calculations. Another software developer saw it the other way 
around with the argument that there is no point in being fast if you are 
being wrong.  

 The result is contingent of the user's knowledge. For the results to make 
sense, it is useful to compare the results to a reference value.  

 Grasshopper is excellent at making visualisations and hence it should be 
utilised.   



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

36

4.2.8 Connection to part one of the research question 

The first part of the research question and the interview results related to it is 
presented below. 
 

What is required… 
…in terms of input data and results? 
Some argue for the use of EPDs but most thought that generic, national 
data is of value. Regarding results, stakeholders from all professions were 
united around the emphasis on visual results. 

 
…in terms of transparency?  
The importance of transparency varies depending on the user and on the 
project stage.  

 
…in terms of connection to a 3D model? 
The connection to a 3D model is of value to most stakeholders, however a 
little less to real estate developers. There were different preferences on 
how to build the geometry and a variety of CAD software was proposed. 

 
…in terms of calculation speed? 
An early-stage tool must be fast to enable different iterations when the 
project team is pressed on time in early stages.   

  
…in terms of software skills and LCA experience of the user? 
There can be different branches of the tool, requiring varying LCA and 
modelling experience. However, a software like grasshopper is hard to 
learn and might not be suitable for such a tool. Architects seem to be a 
suitable user group as they are working with 3D models in early stages. 

  



 
 
 

CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 37 
  

4.3 Tool review 
A summary of properties of the studied tools is presented in Table 5. 

Table 5. Scheme of tool properties. 

Tools 

B
yg

gs
ek

to
rn

s 
M

ilj
öb

er
äk

ni
ng

sv
er

kt
yg

 
(B

M
) 

O
ne

Cl
ic

k 
LC

A
 

T
he

 B
ui

ld
in

gs
 a

nd
  

H
ab

it
at

s 
ob

je
ct

 M
od

el
 

(B
H

oM
) 

Properties 

Connection to a 3D model No Yes Yes 
Functionality to add EPDs Yes Yes Yes 
Has data for the Swedish market Yes Yes Yes 
Reference study period 50 years Varies 50 years 
Additional impact categories 
besides Global Warming 

No Yes Yes 

Modules A1-A5 Varies A1-A3 
Web-based tool No Yes No 
Desktop tool Yes No No 
Plug-in tool No Yes Yes 

 

4.3.1 Byggsektorns Miljöberäkningsverktyg (BM)  

BM is a desktop tool provided by IVL (IVL, 2021). It holds a database with 
environmental data of resources representative for the Swedish market. The aim 
of the tool is to widen the use of LCA in the building industry, lower the climate 
impact and enable resource efficient construction. It can be used to calculate the 
embodied carbon in MB and hence make a great impact in the industry. The 
focus is on the modules A1-A5 and the quantities of building materials can be 
added to the tool via excel or manually. There is a possibility to add EPDs. The 
results are extracted as a report in excel with numbers and graphs (Figure 30). 
The tool offers subscription plans and trial periods. 

 

Figure 30. Result extraction from BM. 



CHALMERS Architecture and Civil Engineering, Master’s Thesis ACEX30 
 

38

4.3.2 OneClick LCA  

OneClick LCA is both a web-based tool and a plugin tool allowing connections to 
Rhinoceros, Revit, Excel and other software (OneClick LCA, 2021). There are 
subscription plans and trial periods available. The tool allows for comparing 
different designs of a project at different stages. It can be used for different 
certifications like BREEAM, LEED, MB and NollCO2. LCA phases, impact 
categories and the reference