TOWARDS THE INDUSTRIAL REUSE PROCESS Amilia Björklund & Maja Lindborg Master Thesis Chalmers School of Architecture 2021 Examiner: Liane Thuvander Supervisor: John Helmfridsson REUSE IS THE NEW USE Reuse is the new Use Towards the industrial reuse process © Amilia Björklund, Maja Lindborg, 2021 Chalmers University of Technology Department of Architecture & Civil Engineering Architecture & Planning Beyond Sustainability Gothenburg, Sweden 2021 Examiner: Liane Thuvander Supervisor: John Helmfridsson ABSTRACT Working towards a circular building industry is one of the prerequisites for solving the issues on large amounts of demolition waste and emissions from new construction projects. This includes the circulation and reuse of existing building materials and components. What is lacking are established processes for designing with reused building parts on an industrial scale. The aim of this thesis is therefore to explore how inventories and information management can facilitate a reuse design process on an industrial scale. The first part of this thesis uses literature studies on current research, reference reuse projects and semi- structured interviews with actors in the building industry to get an understanding of the reuse process of today. It identifies different types of inventories and how they could be used further in the design process through the connection with BIM. The second part of this thesis is a pilot project in collaboration with an ongoing pre-study by Familjebostäder to add housing on top of an existing apartment building from the 70’s in central Gothenburg. The pilot project implements the findings from the first part in a rooftop design proposal with reused timber- frame wall elements. The elements are sourced from two preschools in Gothenburg set to be demolished within the coming year, through a collaboration with Lokalförvaltningen. As a conclusion, this thesis proposes an interconnected inventory process to make the information flow more efficient. The key to a successful inventory relies on visibility (how to visualise the content of your inventory) and compatibility (how to connect your inventory data to further usage).The architect’s reuse design process would benefit from integrating the inventory data directly into the BIM software. In this thesis, a concept toolchain and workflow for connecting a reuse database to the BIM model was developed and tested. Furthermore, analysis of cost comparisons, carbon emissions and disassembly feasibility in the pilot project showed that element reuse is more feasible than material reuse on an industrial scale, and that element reuse of timber frame buildings provides an interesting business model for prefab factories. Key words reuse, circular economy, circular building industry, material inventories, information management, BIM AMILIA BJÖRKLUND MAJA LINDBORG BSc Architecture Chalmers University of Technology 2014-2017 Architecture internship Studio Ekberg, Gothenburg 2018-2019 MSc Architecture & Urban Design Chalmers University of Technology 2019- ERASMUS Exchange year Politecnico di Torino, Italy Autumn 2019 Additional real case project autumn 2019- Planning and project leading the transformation of a barn with reused materials. The starting point for this thesis was a shared interest and passion for a circular construction industry - Amilia from a more practical point of view and Maja from a more digital point of view, which has proven to complement each other well. BSc Architecture & engineering Chalmers University of Technology 2014-2017 Computational design internship Smart space, Buro Happold, London 2017-2018 Architecture internship Abako arkitektkontor, Gothenburg 2018-2019 ERASMUS Exchange year TU Delft, Netherlands 2019-2020 MSc Architecture & planning beyond sustainability Chalmers University of Technology 2019- Inspirational speaker Arkitekturgalan 2019 Spoken word poem on the power of reuse with a complementary outfit. AUTHORS ACKNOWLEDGMENTS First of all, thank you to Emilio Brandao for acting as a match maker and bringing us together - a match made in heaven! * * * A special thanks to our supervisor and examiner, John Helmfridsson, and Liane Thuvander, for your expertise and support throughout the project. Thank you to Leo Odby at Familjebostäder for giving us a demand project to work with and Angélica Karlsson at Lokalförvaltningen for contributing with supply projects, and to Carina Loh Lindholm at IVL and the organisation of CCbuild for providing us with a reuse database. * * * This thesis is built upon the knowledge and experience from people all across the building sector. A big thank you to Dave Benninck at REUSE Consulting, Anders Carlsson at Derome, Leo Fiedler at Trafikverket, Marie Johansson, Karin Sandberg and Carmen Kristeneu at Rise, Peter Lindblom at the ACE workshop, Ellinor Ödéen at Moelven and Klas Österberg at Demontera for your valuable viewpoints on reused timber constructions. Thank you to Jan Axlund and Joe Palmer at Dacke App, Jonas Dahlstrand at Projektutsikter, Jakob Danckwardt- Lillieström and Karin Stenberg at Kaminsky, Christine Delander-Eksten at Helsingborgshem, Karin Hedén and Thomas Landenberg at White, Åsa Holmberg at Relement, Per Håkansson at Kompanjonen and Mikael Lunneblad at Familjebostäder for sharing your experiences and expertise on reuse processes and inventories. Also thank you to Camilla Berggren-Tarrodi at ÅWL and William Westin at Chalmers for your rewarding reflections on BIM workflows and to Thomas Lundberg at European Rooftop Network for your inspiring input on rooftop architecture. It is because you took your time and patience to explain the most trivial of things to us, that this thesis exist. Let it be a reminder that the only way towards a circular built environment, is together. * * * Last but not least, thank you to family and friends for the continuous discussions and feedback, and for the times you just provided dinner and a conversation about something entirely different. INTRODUCTION Why & how reusing materials? 8 Background� 10 Research questions� 14 Aims & objectives� 15 Audience� 15 Method� 16 Delimitations� 16 Theoretical framework 16 REUSE TODAY � 1.SUPPLY AND DEMAND Inventory in practice� 20 Developing the process diagram 21 2. INVENTORIES What & why inventory?� 26 Urban mining� 30 Environmental inventory� 31 Reuse potential inventory� 32 The Reuse report� 36 Detail inventory� 37 3. INFORMATION MANAGEMENT Synchronizing the data� 40 Logging and storing inventory data� 43 Organising and visualizing BIM object data� 44 BIM compatibility tools and methods� 45 4. DISCUSSION On site & off site supply 48 Doing the right thing at the right time 48 Visibility & compatibility 49 REUSE TOMORROW 5. PILOT PROJECT Briefing documents The commission 53 On site supply� 56 Off site supply� 57 Reuse report� 60 Project planning documents Design with on site supply� 65 Design with off site supply� 66 Building permit� 70 Construction documents Off site supply 1: Timber frame walls� 75 Off site supply 2: Doors� 80 Design with off site supply� 81 Final proposal Construction principle� 94 Life cycle assessment & cost calculations 96 CONCLUSION 100 REFERENCES 104 APPENDICES Appendix A. Detail plan Olivedal 27:12� 109 Appendix B. Post-fab panels� 110 Appendix C. LCA� 113 Appendix D. Calculations� 118 Appendix E. Reference process diagrams� 121� Appendix F. Testing BIM compatibility� 125 TABLE OF CONTENTS I II GLOSSARY Building part The general word for a part from a building at any scale used in this thesis. Building elements see page 34. Building materials see page 34. Building components see page 34. Building interior see page 34. BIM see page 41. BIM software see page 41. BIM model see page 41. BIM object see page 41. Briefing document Programhandling Stage 0-1 according to RIBA stages. Project planning document Systemhandling Stage 2-3 according to RIBA stages. Construction document Bygghandling Stage 4 according to RIBA stages. Environmental inventory Miljöinventering Also called waste audit or pre-demolition audit. Colour codes Reuse/ Supply New construction/ Demand Inventory 98 INTRODUCTION The idea of a circular building industry is quickly moving from a theoretical utopia to a concrete vision and reality. This includes the circulation and reuse of existing, pre-used building materials and components. Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply INTRODUCTION Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Virgin materials account for 84%of emissions in a new construction EU-target: 70%recycle or reuse by 2020 DESIGN WITH REUSE MORE PILOT PROJECTS CLIMATE DECLARATION INDUSTRIAL REUSE DESIGN FOR DISASSEMBLY Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply WHY REUSING MATERIALS? DECREASE USE OF VIRGIN MATERIALS About 10% of Swedish carbon emissions comes from new constructions, with the largest contributing factor being the use of virgin materials. 84% of emissions from new constructions are coming from materials (Boverket 2021) (IVL 2015, 38). The construction industry's goal is to have net zero emissions by 2045 (Fossilfritt Sverige n.d.). MINIMIZE CONSTRUCTION WASTE AT DEMOLITION SITES CLIMATE DECLARATIONS FOR NEW CONSTRUCTIONS Each year, Sweden produces over 12 million tons of construction waste (Naturvårdsverket 2020). By 2020, the goal was a 70% reuse/recycling rate (Regeringskansliet 2019). As a reference, about 52% was estimated as recycled in 2018 (Boverket 2021). Starting in 2022, all new construction projects need a climate declaration of the building frame and envelope, including a life cycle assessment, LCA. According to current ISO standards, reused materials score better than virgin materials in life cycle calculations (IVL 2021). HOW REUSING MATERIALS? (RE)USING WHAT WE HAVE MAKE IT INDUSTRIAL MORE PILOT PROJECTS! To be able to develop industrial, circular business models, more pilot projects are needed to test and implement ideas and share them with the rest of the industry. Reuse needs to be implemented on an industrial scale to reach higher quantities and better profitability. This means we need to find efficient and smart workflows for how reuse can be integrated into the design process, but it also means understanding what kind of building parts are most feasible to reuse in the first place. There is a lot of talk about design for reuse, called "design for disassembly", and that is great - but we need to start designing not only for future reuse, but design with reuse already today. 1110 BACKGROUND In a circular building economy, demolitions and new constructions can be seen as supply and demand projects, as described by Rose and Stegemann (2018, 7) (see figure 1). If the reuse market could reach this kind of balance, it has large potentials to success as a business model, since supply and demand form the most fundamental concepts of a market economy (Investopedia 2020). When looking more specifically at the reuse process, it can be defined as a constant and indefinite relationship between supply projects and demand projects (Rose & Stegemann 2018, 7). The process might be circular, but time is linear. As shown in the illustration below, a construction starts as a demand project - indicates red colour - and is by the time of deconstruction switched to be seen as a supply project - indicates the gradient switch to green. The yellow connection in the diagram is describing the flow of materials and information between the supply and demand project. The owners of this information include all stakeholders in the building industry - from architects, reuse consultants and property developers to second hand market places, recondition companies and storage companies. As such, methods and tools for efficient communication between all these actors are one of the most important prerequisites for a working industrial reuse industry. SUPPLY AND DEMAND DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED Reuse targets PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION PROGRAMHANDLING SYSTEMHANDLING DEMOLITION PROCUREMENT DECONSTRUCTION BYGGHANDLING CONSTRUCTION SUPPLY PROJECT SUPPLY SUPPLY DEMAND PROJECT DEMAND DEMAND USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION FLOW OF BUILDING PARTS & INFORMATION BUILDING PARTS FLOWINFORMATION FLOW (INVENTORIES & INFORMATION MANAGEMENT Design with on site reuse targets Figure 1. The relationship between a supply and demand project (adopted illustration, Rose and Stegemann 2018). INTRODUCTION CIRCULAR PRECONDITIONS To reach a circular building industry, including the usage of reused materials, the city of Gothenburg together with Kaminsky architects have developed a diagram summarising the ten most important preconditions (see figure 2). Two of them have a clear relation to methods and tools for efficient communication - inventories and information management. Inventory - a complete list of items such as property, goods in stock, or the contents of a building (Oxford dictionairy). 1. Material inventories • Knowledge on material inventories needs to be developed. • More time is needed in the pre-study phase to allow for material inventories and analysis. • Classification of materials according to reuse potential should be an obvious part of the material inventory. • The result of the material inventories need to be connected to digital databases to enable the information to be used during planning and project planning. (Göteborgs stad 2020, 17) 2. Information management • Business models for digital information management need to be established. • Regulations and agreements around how to log and store information on building parts need to be established. • There is a need for digital tool development, to be able to store and update information about building parts and their position. The tools need to work both during project planning, construction, maintenance and demolition. • There is a need for database models for public access to information on building parts, such as material composition and assembly and disassembly guidelines. These databases need to be integrated in the tools for project planning and management. (Göteborgs stad 2020, 17) Information management - the process of collecting, organizing, storing and providing information within a company or organization (Cambridge dictionary). MATERIAL INVENTORIES INFORMATION MANAGEMENT CIRCULAR PRECONDITIONS DESIGN FOR REUSE LAWS, REGULATIONS, CERTIFICATIONS BUILDING TECHNIQUE REUSE TECHNIQUE MANAGEMENT MODEL ENVIRONMENTAL CALCULATIONS ECONOMIC FEASIBILITY REUSE MARKET MATERIAL INVENTORIES INFORMATION MANAGEMENT CIRCULAR PRECONDITIONS DESIGN FOR REUSE LAWS, REGULATIONS, CERTIFICATIONS BUILDING TECHNIQUE REUSE TECHNIQUE MANAGEMENT MODEL ENVIRONMENTAL CALCULATIONS ECONOMIC FEASIBILITY REUSE MARKET Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Figure 2. Circular preconditions (adopted illustration, Göteborgs stad 2020). 1312 There are several organisations, national as well as international, working towards a circular economy. Centrum för cirkulärt byggande (Center for circular construction, short: CCbuild) is a Swedish innovation project and organisation run by IVL Svenska Miljöinstitutet. Since 2015, they have been working towards industrial reuse and circular material flows through a number of services: • a multi-disciplinary network and sharing platform through seminars and events • a library of know-how: research articles, guidebooks, reference projects et cetera • digital services such as an inventory database and a market place for reused building parts • providing guidelines on working methods and processes (CCbuild, n.d.) To date, CCbuild is connecting around 30 different companies and organisations within the Swedish building industry (Loh Lindholm, personal communication, May 10, 2021). Overview of the existing building with the possible rooftop addition marked in red. INTRODUCTION Familjebostäder i Göteborg is a property owner and developer with over 18500 rental apartments. They are a part of the real estate group Förvaltnings AB Framtiden, owned by the municipality of Gothenburg (Familjebostäder i Göteborg n.d.). In January 2021, Familjebostäder i Göteborg released a report describing their current work and future vision on circular material flows. It references Framtiden's guideline of "always considering reuse of materials in renovation projects", and analyzes their two REUSE pilot projects which mainly addressed building interiors and components (Franker, Lunneblad, Wilson 2021, 3). In the report, Familjebostäder states that during 2021 they will continue their work on reuse, including more implementations. They also conclude that there is a need for easier and more comprehensive ways of communicating costs and climate savings in relation to reuse (Franker, Lunneblad, Wilson 2021, 24). The site During the spring of 2021, Familjebostäder is conducting a pre-study for the renovation of a four- storey apartment block in Linnéstaden in central Gothenburg, along with a two-storey rooftop addition. The rooftop addition will work as the case study for this thesis, but the renovation of the existing building will not be considered as its extents are still undetermined. A CURIOUS CLIENT WORKING IN NETWORKS View from the courtyard of the existing building at Jungmansgatan. 1514 How can designing with reused building parts become feasible on an industrial scale? How can material inventories develop to facilitate reuse on an industrial scale? How can information management facilitate the implementation of reused building parts in the architect's design process? RESEARCH QUESTIONS INTRODUCTION AIMS & OBJECTIVES The aim of this thesis is to propose solutions on how to reach reuse of building parts on an industrial scale. The focus lies on contributing to the challenges that have a direct connection to the architect's design process: inventories and information management. The aim is further to be able to contribute and implement reuse principles in our future careers. The objectives of this thesis are: • to compile and analyse current parallell reuse processes to identify common methods. • to explore how inventories can develop to facilitate the reuse of building parts on an industrial scale. • to explore how information management can contribute to facilitate the reuse of building parts on an industrial scale. • to explore how and what building parts to reuse on an industrial scale. • to explore these findings in a real case pilot project in central Gothenburg. The target group for this thesis is stakeholders in the building industry, to explain and highlight the benefits and possibilities with actively working with reuse in their building projects. Architects are provided with a guide with process steps to follow when working with reused building parts, and how these steps relate to the phases in a standard design process. Furthermore, it can provide them with insights into some of the aesthetic design consequences that the implementation of some reused building parts can have. Property developers can gain knowledge on the benefits as well as challenges that exist when deciding to apply reused building parts in a project. Computational design consultants and BIM developers can get an understanding of how the feasibility on reusing building parts heavily relies on a way to make inventories compatible with a BIM tool, and how this could be done on a conceptual level. Environmental inventory specialists and reuse consultants can get an understanding on how interconnected inventories can help to make the inventory process more efficient and increase the feasibility of reusing building parts. Product suppliers, prefab manufacturers and demolition firms can get an understanding on how circular economy will change the building sector and how they can develop to adapt to a new kind of business. Building permit department at municipalities can get an understanding on how circular economy will change the building sector and how they can develop to adapt to new kind of conditions that requires a larger extent of flexibility. AUDIENCE 1716 METHOD This thesis uses research by design through an iterative process with a pilot project connecting theory and practice. The theoretical framework A literature review of research papers and reference projects to understand the basis of the current reuse industry today Semi-structured interviews with around 25 different stakeholders in the building sector, either providing their experience on the current reuse industry and/or finding out ways to improve it. • Architects • Reuse consultants • Deconstruction firm • Property owners/developers • Timber prefab company • Researchers • Construction engineers Seven of the actors share experience from seven real case processes and in total, ten material inventories could be collected and analysed. The practical process Three site survey inventories to strengthen the understanding of the theoretical investigations within this field. • Roof of Jungmansgatan • Biskopsgatan's preschool • Östra Palmgrensgatan's preschool The design of a pilot project with reused building parts on Jungmansgatan with a design process following the phases from a standard Swedish construction process (see Glossary page 7). This included life cycle assessment and estimated cost calculations. The BIM compatibility development including practical investigtions in Revit and Grasshopper.Inside. Revit to develop a method to design with reused building parts in a BIM software. The investigations included: • Workflow concept • Toolchain concept • Test scripts to confirm feasibility DELIMITATIONS The pilot project is a rooftop addition and a housing project creating the following delimitations: • Building interiors are not considered. • A rooftop addition requires a light-weight construction. This excludes concrete and brick reuse. Focus is on the building frame and envelope. This includes exterior walls (including doors and windows) and roofs. The focus is on designing with reused building parts. As per the circular conditions diagram (see figure 2 on p. 11), this includes "Material inventories" and "Information management". The focus in this thesis is on industrial reuse processes. As per the circular preconditions diagram, this includes "Economic feasibility". As such, the other seven preconditions are outside the scope of this thesis. INTRODUCTION THEORETICAL FRAMEWORK None of the previous Chalmers theses within the field of building reuse have had a specific focus on industrial reuse and the conditions that follows (Wilder 2017, Josefsson 2019, Andersson & Nilsson 2020, Jörlén 2020, Grmela 2020). The main starting points for this thesis has therefore been the Circular preconditions report with an industrial focus, published by the city of Gothenburg in 2020. It describes the needs to be able to reach reuse on an industrial scale through ten categories, of which this thesis is focusing on Inventories and Information management (see Background chapter). Additionally, Josefsson's thesis Form follows availability from 2019 provided a great basis for understanding the current reuse industry in a larger context, along with its possibilities and obstacles (Josefsson, 2019). Terminology The concept of describing reuse processes through supply and demand projects comes from Rose & Stegemann (2018, 7). To divide supply projects into on site supplies or off site supplies was defined by Wilder in her thesis Constant Change (Wilder 2017, 58). Methodology Jörlén (2020) is using semi-structured interviews to understand the reuse process in reality, which resulted in a realistic thesis and inspired this thesis to do the same, however with a more specific focus on inventories and information management. Andersson & Nilsson (2020) used a real pilot project and client to practically test the reuse process. This thesis uses the same method but in a larger, industrial scale and not all the way through construction. Inventories Jörlén concludes her thesis by stating the need to establish structures and routines for doing inventories, such as what to include, what paramters to log and how to make the inventories further accessible (Jörlén 2020, 33). This is analysed further in this thesis. Information management Josefsson states the importance of increased transparency and availability of information to support informed decision-making (2019, 100). This is further mentioned by one of the interviewees in Andersson & Nilsson's thesis, calling out for a documented design program to make the reuse vision visible for stakeholders throughout the project (2020, 34). In a similar way, Sweco architects specifically claims BIM tools as a way of dealing with this type of circular information management (Eriksson 2019, 87). The architect's design process Grmela (2020) proposes reuse of facade elements which is further discussed and analysed in this thesis as a way towards industrial reuse. Andersson & Nilsson (2020) propose making window intervals on building permit drawings to allow for a flexible design, a method used in the pilot project of this thesis. 18 PART I REUSE TODAY Investigating current practices for reuse. Understanding the overall process and status of today's reuse industry. 1.SUPPLY AND DEMAND 2120 INVENTORY IN PRACTICE To understand how the reuse process works in reality, seven ongoing reuse projects have been analysed through semi- structured interviews with one of the stakeholders in the project. These reuse projects are shortly introduced here. Stadskvarteret Demolition of existing apartment buildings to build new housing blocks in Helsingborg. PROPERTY DEVELOPER Helsingborgshem ARCHITECT Jaennecke Arkitekter REUSE CONSULTANT Helsingborgshem (internal) CONTRACTOR Serneke GROSS AREA 6300 m2 Kromet/Kaj 16 Demolition of an office building (Kromet) to build a new mixed-use building (Kaj 16) in Gothenburg. PROPERTY DEVELOPER Vasakronan ARCHITECT Dorte Mandrup REUSE CONSULTANT White Arkitekter CONTRACTOR Ramboll GROSS AREA 37 500 m2 Kustgatan Remodeling project of an office building into housing in Gothenburg. PROPERTY DEVELOPER Familjebostäder ARCHITECT Sunnerö Arkitekter + Unit Arkitektur REUSE CONSULTANT Reclaimd CONTRACTOR RO-gruppen GROSS AREA 5926 m2 Onsala Rymdobservatorium Remodeling project of a space observatory at Råö in Halland. PROPERTY DEVELOPER Chalmersfastigheter ARCHITECT White Arkitekter REUSE CONSULTANT Reclaimd CONTRACTOR NCC GROSS AREA 500 m2 Bromma Sjukhus Remodeling project of a hospital in Stockholm. PROPERTY DEVELOPER Vectura fastigheter ARCHITECT White Arkitekter REUSE CONSULTANT Kaminsky Arkitekter CONTRACTOR Skanska GROSS AREA 25 000 m2 Europahuset Remodeling project of an office building into housing in Mölndal. PROPERTY DEVELOPER Balder fastigheter ARCHITECT White Arkitekter REUSE CONSULTANT White Arkitekter CONTRACTOR not decided GROSS AREA 42 000 m2 Panncentralen Högsbo Demolition of a boiler room in Gothenburg. PROPERTY DEVELOPER Familjebostäder ARCHITECT - REUSE CONSULTANT Reclaimd CONTRACTOR Hål i Betong GROSS AREA 450 m2 PART I - REUSE TODAY DEVELOPING THE PROCESS DIAGRAM DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED Reuse targets PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION PROGRAMHANDLING SYSTEMHANDLING DEMOLITION PROCUREMENT DECONSTRUCTION BYGGHANDLING CONSTRUCTION SUPPLY PROJECT SUPPLY SUPPLY DEMAND PROJECT DEMAND DEMAND USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION FLOW OF BUILDING PARTS & INFORMATION BUILDING PARTS FLOWINFORMATION FLOW (INVENTORIES & INFORMATION MANAGEMENT Design with on site reuse targets This chapter uses the supply and demand diagram by Rose and Stegemann (introduced in the Background chapter) as a base for illustrating the flow of information and building parts between a supply and demand project. Based on semi- structured interviews of actors from the seven ongoing reuse projects introduced on the previous page, the diagram has been adapted to show how inventories and information management play a role at different stages throughout the reuse process. The diagram can be extended by specifying the standard procedure steps for the supply and demand project respectively. In this thesis, the supply project is divided into a demolition procurement - the time when the demolition permits are approved and procurements are done (Boverket, 2021) - and the actual deconstruction. The demand project is divided into the three standard building phases in Sweden (Johansson 2018, 10) - programhandling, systemhandling and bygghandling - as well as the construction phase (see figure 3). The diagram indicates that the flow of information is occuring before and during the demolition procurement in a supply project, and during the three first phases in a demand project. The flow of building parts happens between the deconstruction phase in the supply project and the construction phase in the demand project. The time aspect Completing a building project can vary between 2-15 years, while the time between the decision to demolish and the start of the demolition is much shorter - in a smooth process as short as ten weeks (Fiedler, personal communication, February 17, 2021). The fact that the demolition procurement is proceeding quickly can be a big problem when it comes to taking care of building parts. Sometimes, there is not time to save anything at all, and what has not managed to get a new owner before the demolition will go to waste (Holmberg, personal communication, January 28, 2021). This is confirmed by one of the reuse consultants interviewed, who admits that building parts that have not found new owners before the demolition starts gets thrown away due to the lack of a viable intermediate storage business model and actor (Håkansson, personal communication, January 22, 2021). Several of the interviewees in this thesis have indicated the same experience, adding to the importance of starting as early as possible with an inventory process to make sure there is enough time to save as much as possible. In an interview with a reuse consultant at White architects about the ongoing reuse project Kromet in Gothenburg, it is explained that the inventory has been performed at an early stage to identify building parts with a reuse potential. As a result, clear instructions could be given already in the demolition procurement on what and how to deconstruct. Figure 3. Supply and demand project in relation to each other showing how information flow as well as flow of building parts are happening in the process (adopted illustration based on Rose & Stegeman 2018 and summary of analysis of reuse projects). SUPPLY & DEMAND 2322 After a first inventory, several of the actors from the interviews have set some kind of targets on what to reuse. Apart from being used as instructions for the demolition firm, as in the case of Kromet, it has further led to the planning and designing with these building parts. In combination with additional inventories performed it has been possible to settle a final design already in the systemhandling (see figure 4). Figure 4. How inventories of the supply project are performed at an early stage in the building process to be able to plan for the building parts in the design before it gets demolished (summary from analyse of several reuse processes). DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED Reuse targets PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION PROGRAMHANDLING SYSTEMHANDLING DEMOLITION PROCUREMENT DECONSTRUCTION BYGGHANDLING CONSTRUCTION SUPPLY PROJECT SUPPLY SUPPLY DEMAND PROJECT DEMAND DEMAND USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION FLOW OF BUILDING PARTS & INFORMATION BUILDING PARTS FLOWINFORMATION FLOW (INVENTORIES & INFORMATION MANAGEMENT Design with on site reuse targets Off site vs on site supply 6 out of 7 reuse projects in this thesis were remodeling projects. The reuse implemented in the design was mainly the same building parts that already existed on the same site - a so called on site supply as defined by Wilder (Wilder 2017, 20). This meant that the deconstruction could be matched with the new construction. Additionally, the storing of the deconstructed building parts could in most cases be solved by storing it on the same site until the construction started. Conclusively, although the inventories still had to be done in an early stage to have time to implement it in the design, the logistics when working with an on site supply are less complex than if the supply project would have been another building, at another site, with another owner. One reuse project that did not have an on site supply as its primary supply is Onsala Rymdobservatorium, developed by Chalmersfastigheter. They were instead looking for building parts from so called off site supplies as defined by Wilder (2017, 20). The project leader explains that they initially planned the building as in any conventional design process, but designed with flexible principles according to their reuse targets, as they did not know from the start what building parts they would find. Along with the design process they had to scout for building parts and store them until the time of the construction. When working with an off site supply, one of the challenges is to set reuse targets without knowing what building parts that will exist at the time of the construction. The project leader at Onsala Rymdobservatorium mentions that in the programhandling phase, they based their reuse targets on a statistical estimation, meaning they investigated what reused building parts are available today and have a high possibility to also be available in the future. This is represented as an Urban mining in figure 5. The inventories of the building parts from the off site supply were performed by the owner of the off site supply, after which Chalmersfastigheter could get hold of this information to make a choice on whether to use it or not. The reuse targets from the urban mining could in this way be matched with the information from the off site supply in the bygghandling phase, and with this they could finalise their design (see figure 5). PART I - REUSE TODAY In the case of Chalmersfastigheter, they had an on site supply from a smaller building needed to be taken down to make way for the new building. As for the off site supplies, they had several. To illustrate that, the diagram could be complemented with several off site supplies. For the on site supply however, there can of course never be more than one. The final diagram (see figure 5) shows the complexity of the relationship between supply and demand projects. The communication between them heavily relies on the inventories and especially how the information from the off site supplies are managed further in the reuse process. These two themes - inventories and information management - will be further analysed and discussed in chapter 2 and 3 respectively. Industrialising the reuse process What prevents demand projects from buying the off site supply earlier in the design process? The interviews in this thesis indicates that the storing of reused building parts is an unavoidable issue and a Off site Urban mining inventory leading to off site reuse targets DEMOLITION PROCUREMENT DECONSTRUCTION DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED INVENTORIES PERFORMED Final design PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION OFF SITE SUPPLY ON SITE SUPPLY DEMAND On site reuse targets Design with flexibility from off site reuse targets Figure 5. When working with an off site supply, an urban mining is done by the demand project to implement in a flexible design. The urban mining reuse targets are matched with information from inventories from the off site supply in the bygghandlingsphase to set the final design (summary of analysis of reuse processes). challenge from many aspects. Buying reused building parts early in the process of a new construction requires storage for a longer and at times uncertain period of time, which is both a logistical, judicial and economical issue. It raises questions on who owns the building parts in-between usage and thus who pays for it. Additionally, because of the uncertainties of the time frame of a new construction - pro-longed building permit procedures and unexpected appeals among many - buying and storing a reused building part too early could end up long and expensive (Dahlstrand, personal communication, Mars 19, 2021). A comparison can be drawn to the prefabrication industry and the production of new building elements. One example is Derome, one of Sweden's major prefab timber companies. When their productions are planned there are automatic reservations of amount of materials needed, and automatic purchase orders done to their suppliers (Carlsson, personal communication, February 1, 2021). An industrial process builds upon smooth transitions where administration and working hours are minimised, and materials arrive just-in-time. SUPPLY & DEMAND 24 PART I - REUSE TODAY Investigating the purpose and methods for doing different kinds of reuse inventories, with a focus on how they relate to the architect's design process and reuse on an industrial scale. 2. INVENTORIES "If it is not documented, it doesn't exist." - Louise Fried 2726 WHAT & WHY INVENTORY? LEVELS OF INVENTORIES Inventories can be performed by many different stakeholders using very different methods, but they all have a similar purpose. This chapter analyses ten different reuse inventories and seven ongoing reuse projects along with practical site survey inventories to understand how and why an efficient inventory process can be performed. An inventory is not directly connected to a reuse purpose. In any business or organisation holding a physical stock, the inventory is considered one of the most important assets to understand and monitor your business (Unleashed 2015). Stores, warehouses and companies are obliged by law to perform inventories of their stock each year to account for their total value (Skatteverket 2021). One of the main reasons for making an inventory is to get an overview of what you own - a way of realising the actual value of your stock. When it comes to reuse inventories, large amount of resources could be saved if doing inventories of the existing building stock, as the information contributes to making it available to a larger extent (Håkansson, personal communication January 22, 2021). Furthermore, inventories are needed to be able to plan for the reused building parts in the new construction projects (Göteborgs stad 2020, 10). The inventories analysed in this thesis have shown a large variation in detailing. Some of the inventories were only using an estimated grading on the reuse potentials of the building parts, while some had detailed information such as measurements or building code requirements. The level of detailing is mainly determined by: • the purpose of the inventory • the size of the project • in which phase of the project the inventory was made What differed differed one inventory from another was whether it led to a reuse target or not (see chapter 1). Some of the inventories were made to identify the reuse potential of a certain building part, as a base for a decision to set reuse targets. Other inventories were made after such a decision already had been taken, and in those cases the purpose was to collect all the additional information needed to be able to implement it in a design. Another important aspect is the size of the project, as it determines how focused the inventory needs to be. In a smaller project, it might be possible to inventory all building parts with a high level of detailing throughout the building, but in a larger project there is a need to limit the focus to a certain type of building part. In the reuse process of Kromet, the detailed inventory took a very long time since they did not limit themselves to any specific materials or products (Hedén, personal communication February 11, 2021). In another project - Panncentralen in Högsbo - the building was small enough to be able to inventory the detailed information from the start (Reclaimd 2020). "In the same way that daylight, terrain, infrastructure and soil conditions are mapped and analyzed at the beginning of a project, an inventory of the conditions for reuse on the site must be a natural part of every analysis to identify existing and potential qualities and values." (Andersson & Nilsson 2020, 33) PART I - REUSE TODAY INVENTORY METHODS Lendager Group calls the method of collecting most of the inventory information from drawings a desktop mapping (Lendager Group 2019, 17). To visit the demolition site to collect information is defined as a site survey by Rose and Stegemann (2018, 5). According to Lendager Group, a desktop mapping should always proceed an actual site survey. Depending on the amount of information that can be gathered from the desktop mapping, a site survey is simply a way of verifying that the gathered information was corrent and up-to-date (Lendager 2019, 17). This was confirmed during the practical site surveys made in this thesis, where a lot of time could be saved by mapping the type and amount of windows by using as-built facade drawings prior to the site survey, and only using the site survey to check on the condition of the windows. It was however noted that the possibility of doing a desktop mapping depends on what building part to inventory, as building interiors generally are not shown in as-built documents to the same extent and therefore might need more time on the site survey. One of the reuse consultants interviewed used a pre- decessor to the digital tool CCbuild Produktbanken (see chapter 3 on Logging and storing inventories) to perform an inventory. Quite soon, it became obvious that the level of detailing in the tool was too extensive for the purpose of the inventory, and they ended up using a conventional spread sheet, customising the inventory after their own needs (Stenberg, personal communication January 25, 2021). Conclusively, the analysis showed that inventories can be performed on a scale depending on its purpose and its level of detailing, and that the inventory methods differ accordingly. In this thesis, four different types of inventories were identified (see figure 6). Hoppet inventory TYPE OF INVENTORY Reuse potential inventory REUSE CONSULTANT Lendager group PROPERTY OWNER Lokalförvaltningen Kromet inventory I TYPE OF INVENTORY Reuse potential inventory REUSE CONSULTANT White Arkitekter PROPERTY OWNER Vasakronan Kromet inventory II TYPE OF INVENTORY Detail inventory REUSE CONSULTANT White Arkitekter PROPERTY OWNER Vasakronan Bromma Sjukhus inventory TYPE OF INVENTORY Reuse potential inventory REUSE CONSULTANT Kaminsky Arkitekter PROPERTY OWNER Vectura fastigheter Kustgatan inventory TYPE OF INVENTORY Reuse potential + Detail inventory REUSE CONSULTANT Reclaimd PROPERTY OWNER Familjebostäder Panncentralen Högsbo inventory TYPE OF INVENTORY Reuse potential + Detail inventory REUSE CONSULTANT Reclaimd PROPERTY OWNER Familjebostäder Stadskvarteret inventory TYPE OF INVENTORY Reuse potential inventory REUSE CONSULTANT Helsingborgshem PROPERTY OWNER Helsingborgshem Eriksboskolan inventory TYPE OF INVENTORY Environmental inventory ENVIRONMENTAL CONSULTANT Relement PROPERTY OWNER Lokalförvaltningen Form follows availability inventory TYPE OF INVENTORY Reuse potential + detail inventory REUSE CONSULTANT Taleen Josefsson PROPERTY OWNER - Towards zero-waste buildings inventory TYPE OF INVENTORY Reuse potential inventory REUSE CONSULTANT Václav Grmela PROPERTY OWNER - LIST OF INVENTORIES To understand how the inventory process works in reality, ten inventories have been analysed and are presented below. The analysis showed that the inventory methods differed in the same ways as the inventories themselves. INVENTORIES 2928 Figure 6. Summary of the four types of inventories identified in this thesis (Gontia P. et al. 2018, Göteborgs stad n.d., Kaminsky 2020, CCbuild Produktbanken 2021). PART I - REUSE TODAY INVENTORIES ENVIRONMENTAL INVENTORY An inventory to sift out what is possible to reuse URBAN MINING An inventory to understand what exists to reuse Purpose: To get a broad picture of what building typologies or building parts exist in the society and what is frequently demolished to be able to get an expectation of a future supply. Typical inventory parameters: • Construction type/building part • Construction/manufacturing period • Quantity Purpose: To create a basis for the waste management by identifying if and where hazardous substances exist in a building before a demolition. The methods used are ocular inspections as well as taking samples. Typical inventory parameters: • Type of hazardous substance • Location • Quantity/extent Real case example: Real case example: INITIAL INVENTORIES DETAIL INVENTORY Inventories to collect further information after a decision on what to reuse has been taken REUSE POTENTIAL INVENTORY An inventory to sift out what is feasible to reuse Purpose: To get an idea of the reuse potential of building parts where the final decision of the potential depends on the sum of several parameters. The economic and environmental aspects has shown to be the most decisive ones. Typical inventory parameters: • Economical value • Environmental savings • Quantity • Disassembly feasibility • Condition • Aesthetics • Future applications Purpose: To collect the additional information needed to be able to implement the building components in a new design. Typical inventory parameters: • Exact measures • Classifications: fire, sound, construction • Upcycling propositions Real case example: Real case example: DETAILED INVENTORIES 3130 URBAN MINING Figure 7. Extract of pre-demolition audits submitted to the city of Gothenburg. To retrieve more detailed information, documents for each building needs to be ordered seperately from the municipality (Stadsbyggnadskontoret, personal communication, January 21, 2021) (Göteborgs Stad 2021). Building with reused materials on an industrial scale requires a constant and large supply and circulation of these materials. To understand the supply, one can look at what generally is being demolished in our cities today. Most demolitions are of course occurring because the in-going materials have worn out or are toxic. In such a case, the general reuse potentials are quite low (Holmberg, personal communication, January 28, 2021). However, there are two other major reasons for demolitions. The first one is that the building no longer serves a purpose or function - that there no longer is a need for it. Such is the case of a lot of apartment buildings in rural areas, where the effect of the ongoing urbanisation leaves the buildings empty and thus expensive to heat and maintain (Eklund et al. 2003, 2). The other reason is that the building does not meet the government's or city's requirements for energy performance or plot ratio. If a renovation or addition to the building is not considered possible or good enough, the only remaining option is to demolish it and replace it with a new building meeting today's standards (Karlsson, personal communication, February 16, 2021). Both of these reasons mean that the building potentially is demolished long before the in-going materials reach the end of their technical life cycle (Eklund et al. 2003, 1). This is where the general reuse potentials becomes higher. Urban mining can be considered an inventory method in a large scale, mapping what materials can be found in supply projects throughout the city, and which of them are most common. As mentioned in chapter 1, in an early stage of a demand project it might be too early to find a specific off site supply project. In such a case, urban mining can be a way of securing a generic supply of building parts. This means that it is possible to understand what type of building parts most likely will be available when the project is in the construction phase, and therefore can plan ahead for them (Dahlstrand, personal communication, Mars 19, 2021). Conclusively, what differentiates the urban mining from the other types of inventory is that it is performed by the demand project rather than the supply project. Furthermore, it is a method allowing generic projections of future supply and as such, it does not provide information detailed enough for a practical application at the project level (Rose and Stegemann 2018, 3). Urban mining methods There are several ways of finding out what reused building parts are going to be available. These have been summarised and analysed by Rose and Stegemann, but are a list of more or less efficient examples and as such more or less industrial. As an example, SuperUse studios coined the term harvest mapping, which is a process where the area around the site is scouted for available waste streams. This is a time-consuming process well outside the scope of the architect and as such far from realistic in a mainstream construction procedure (Rose and Stegemann 2018, 4). One of the more promising processes could be to develop and communicate the existing, mandatory pre-demolition audits that needs to be submitted to the municipality prior to a demoliton. These documents need to include estimated amounts of the in-going materials and are public records, but as of today they are usually hard to find and get an overview of. These records could benefit from being collated in a public platform accessible for the demand side of the project (Rose and Stegemann 2018, 5). PART I - REUSE TODAY ENVIRONMENTAL INVENTORY An environmental inventory is required by law to precede all remodeling and demolition projects to identify potential hazardous substances (Johansson 2018, 15). Furthermore, it aims to be the basis of the tender documents for the procurement of a demolition firm. The outcome of the inventory is an extensive document containing an overview and analysis of all the materials in the building. The document contains images, building history and building drawings to visualise and locate the materials (Holmberg, personal communication, January 28 2021). There is currently no focus on the reuse aspect within the environmental inventory profession, according to an interview with an environmental inventory specialist (Holmberg, personal communication, January 28 2021). Since July 2020, however, a new law requires the 'kontrollplan' that is established together with the material inventory to include what building components that could be reused, and how they should be deconstructed to preserve their value, see figure 11 (Boverket 2020). This idea is also mentioned by the city of Gothenburg, stating that an environmental inventory also could decide on a reuse potential to save time in the next stage of the inventory process (Göteborgs stad 2020, 10). In an interview with an environmental inventory specialist, it is agreed that this would be possible on a basic level - such as grading the condition and take initial measuremeants - but would require up to 25% more time as an estimation (Holmberg, personal communication, January 28 2021). Figure 8. The "kontrollplan" is required to be filled in since July 2020 when doing an environmental inventory (Göteborgs Stad 2020). INVENTORIES 3332 REUSE POTENTIAL INVENTORY As stated in the introduction of this chapter, the reuse potential inventory is the inventory that decides whether the building part is worth reusing or not. The reuse potential has to be done after (or together with) an environmental inventory. In september 2019, Danish architecture firm Lendager Group performed an extensive reuse potential inventory on four preschools for Lokalförvaltningen in Gothenburg. These inventories were not preceded by environmental inventories but rather worked as inspiration for the municipality as what to do with all the in-going materials and components of the buildings. This included desktop mapping as well as site surveys, visualised in an extensive reuse report calculating environmental savings and showing possible future application of the building parts in an idea catalogue (Lendager 2020). It was first after the environmental inventories were done that it was found out that several of the buildings contained large amounts of hazardous substances, which extensively limited the reuse potentials (Karlsson, personal communication, February 16, 2021). Although the idea catalogue contributed as an thorough inspiration source, it was a shame that a lot of time was spent when finally nothing could be reused. Reuse potential parameters Five of the ten inventories analysed in this thesis used a set of parameters to decide on the reuse potential of each building part. From these five inventories, along with input from CCbuild Produktbanken, the most frequently used parameters could be categorised into six types of reuse potential parameters (see figure 9). As stated in the introduction, reuse needs to be implemented on an industrial scale to reach higher quantities and better profitability and that it is needed to understand what kind of building parts are most feasible to reuse. The reuse potential parameters therefore has to be looked at through an industrial lens and always from an economical point of view, since economy is what powers a successful business. One of the seven parameters that could not be directly connected to an economical aspect is the architectural value. The architectural value is important, but it is not discussed further in this chapter as it is a parameter connected to the demand project rather than the supply project - it is up to the demand project to decide what aesthetically fits the new construction. The other six parameters are explained briefly in the following section. 1. Josefsson Value retention: function, cultural, aesthetic Economical value compared to new product Simplicity (minimum amount of processing) Estimated economical value No hazardous substances Aestethic condition Environmental savings Economical value Disassembly feasibility Future application Condition Quantity Functional condition Estimated economical value (what savings can be done) Achievement of today's standards Resource scarcity Environmental savings Environmental savings Environmental savings Potential application Potential application Disassembly feasibility Disassembly feasibility Disassembly feasibility Disassembly feasibility Logistical feasibility Condition Condition Pleased clients Architectural value CO2 value Quantity Quantity Energy intensity for processing/ transformation Proposed waste management according to Delft Ladder Chemical content Future application 2. White 3. Reclaimd 4. Helsingborgshem 5. Kaminsky 6. Produktbanken Figure 9. Mapping of all parameters connected to the reuse potential of a building part. The six most common reuse potential parameters. PART I - REUSE TODAY ENVIRONMENTAL SAVINGS The environmental savings does not have a direct connection to economical aspects, but as this is the main reason for reusing building parts anyway, large environmental savings is a very strong driving force. According to several interviews, the environmental savings have been the starting point to decide on what to prioritise in further investigations on what to reuse. An example is in Europahuset, where one of the architects in the projects mentions that the concrete frame and foundation was set as the main reuse focus due to its large climate impact and economical value (Landenberg, personal communication, January 29, 2021). Environmental savings is referring to the emissions produced in the A1-A3 phase in a life cycle assessment (LCA). Transportation of building parts (phase A4) is a small emission in comparison (BM 1.0). ECONOMICAL VALUE This is referring to the actual built-in economical value compared to a similar new building part. CONDITION The condition is a parameter strongly connected to both the environmental and economical parameters, since reconditioning requires both cost and energy. The main economical expenditures are working hours for reconditioning (Lendager 2021, 39). An aspect to consider when looking at the condition is whether the building part meets today's standards, such as fire or energy requirements (Stenberg, personal communication, January 25, 2021). As stated in the introuction of this chapter, this parameter can only be evaluated through a site survey. QUANTITY There is a larger reuse potential in larger quantities (CCbuild, seminar 22/3). This is confirmed by the project leader at Onsala Rymdobservatorium, dreaming to find one big supply project to find all building parts from, as every transportation is a cost connected to increased working hours and increased emissions (Dahlstrand, personal communication, Mars 19, 2021). FUTURE APPLICATIONS Two purposes for the future application parameter were identified: location and function. The location could be on site, such as interior products being reused within the renovation project (Lunneblad, personal communication, February 3, 2021). The location could also be off site, such as suspended ceiling tiles moved from one office building to another (Hedén, personal communication, February 11, 2021). If no demand project has been found within the time before deconstruction, the future location could also be set to a reuse material supplier (Lunneblad, personal communication, February 3, 2021). The function proposes in what ways the building part could be reused apart from direct reuse. These includes examples of upcycling, such as skirting boards turned into acoustic wall panels (Lendager 2019, 75), or downcycling, such as concrete wall elements turned into entrance benches (Stenberg, personal communication, January 25, 2021) or broken bricks used as foundation aggregate (Josefsson 2019, 58). INVENTORIES 3534 DISASSEMBLY FEASIBILITY The disassembly feasibility has to be taken into consideration because the cost of labour is so much higher than the cost of materials and products (Andersson and Nilsson 2020, 22). The disassembly feasibility varies a lot depending on the type of building part. To evaluate this parameter further, four different categories of building parts have been identified in relation to their disassembly feasibility (see figure 10). Building interior Loose furnishings that need little to no disassembly. EXAMPLES chairs, tables, shelving systems. Building components Individual components including fixed furnishings, that already are designed for disassembly. EXAMPLES windows, doors, toilets, kitchens, light fixtures. Building materials Single materials that also include the separated, individual materials of a building element. EXAMPLES bricks, mineral wool boards, wooden joists, concrete roof tiles. Building elements Walls, floors, ceilings. The main construction parts of the building. Usually layered and consisting of several building materials. EXAMPLES timber frame walls, cut-out brick partitions, prefab concrete slabs with integrated insulation. BUILDING MATERIALS BUILDING ELEMENTS BUILDING INTERIOR BUILDING COMPONENTS CLIMATE DECLARATION BUILDING MATERIALS BUILDING ELEMENTS BUILDING INTERIOR BUILDING COMPONENTS The existing industrial reuse in the building sector today is mainly working with building interiors, as they need little to no disassembly and are smaller and easier to transport and store. An office space is generally refurbished every 3-5 years as the tenants change, making their in-going parts important to reuse from an environmental point of view (Håkansson, personal communication January 22, 2021). Procedures for reuse of building interiors have gone fairly far, with around 15 projects presented at the webpage of CCbuild (CCbuild n.d.). An example is Selma Lagerlöf Center, a cultural public building in north Gothenburg, where reused building interiors were used throughout the 6200 square meter building (White 2019). A building component is also one of the easiest building parts to reuse. According to the sales manager at Dacke App, both interiors and components constitutes "the low hanging fruits" of the reuse market (Axlund, personal communication, January 22, 2021). Kompanjonen is a reuse consultant company focusing on the reuse of building interiors and components (Håkansson, personal communication, January 22, 2021). Figure 10. Building part categories. Interiors & components PART I - REUSE TODAY With industrial reuse systems for building interiors and building components in place, the challenges mainly lie in the industrial reuse of building materials and building elements. The building stock we have today has not been built with methods that facilitates the disassembly of each material in an element. Because of the use of nails, glue and other non-reversible attachments, the disassembly is a time-consuming and thus costly work (Österberg, personal communication, February 28, 2021). Furthermore, the economical value of the element does not lie in each, single material but rather in the assembly of them. A comparison in Sektionsfakta, a reference book comparing the cost of material and labour for different building parts, shows that the material costs of a standard timber frame wall only is about 30% of the total cost (Sektionsfakta 2020, [7.023]). Similarly, the material costs of a steel stud wall is about 40% of the total cost (Sektionsfakta 2020, [7.060]). What can be seen is that the cost of the materials themselves are quite small in comparison to the cost of assembling them. With the same logic, this means that the cost of disassembling the wall material by material would simply would be too time-consuming and thus too costly. Conclusively, to reach industrial reuse of large scale building parts, the focus should be on the reuse of whole building elements rather than building materials. This is confirmed by several sources. The head of Research & Development at prefab timber company Derome examplifies this with a planar element, which costs around 70-80 000 Swedish kronor a piece and include a lot of expensive man hours (Carlsson, personal communication February 1, 2021). In an interview with a project leader at a property developer, it is claimed that the reuse of whole walls and elements is where reuse actually could start become profitable (Lunneblad, personal communication February 3, 2021). Finally, The Delft Ladder is a waste management hierarchy developed in the Netherlands, where element reuse is considered of higher priority than material reuse (see figure 11) (Gorgolewski 2017, 37). There are methods for reusing building elements today. In North America, RE-USE Consulting are working with the de- and reconstruction of large building elements, mainly focusing on single house buildings with timber structures. The company is not working with systematised solutions nor on an industrial scale, but they are experienced around the principles of deconstructing building elements (Benninck, personal communication, Mars 11, 2021). An ongoing research project is Återhus, a collaboration between the architecture office CoDesign, research institute Rise and building contractors NCC. They focus on element reuse of heavy structures in concrete and steel, since these emit high carbon emissions during production and have a long life span (Svensk Byggtidning 2021). The reuse of heavy structures is however outside the scope of this thesis. An issue with element reuse is to manage the element size. The size is a balance between "as few cuts as possible" and "manageable" concerning the weight (Österberg, personal communication February 28, 2021). Figure 11. The Delft Ladder (Gorgolewski 2017). Materials vs elements 1. PREVENTION 2. OBJECT RENOVATION 3. ELEMENT REUSE 4. MATERIAL REUSE 5. USEFUL APPLICATION 6. IMMOBILISATION WITH USEFUL APPLICATION 7. IMMOBILISATION WITHOUT USEFUL APPLICATION 8. COMBUST WITH ENERGY RECOVERY 9. COMBUSTION 10. LANDFILL INVENTORIES 3736 THE REUSE REPORT VISUALISING THE DATA When a reuse potential inventory has been done, it needs to be summarised and visualised towards the different actors of the project; mainly the client, so that he or she can make an informed decision in how to proceed with the reuse process in the project, such as setting reuse targets (CCbuild n.d.). In 7 of the 10 inventories analysed in this thesis, this has been done in the form of a reuse report. An important element of the reuse report is to visualise the inventory in a way that makes it easy to comprehend. This is done by using different visualisation methods to highlight different kinds of data (see figure 13, 14 & 15). From the inventory analysis, eight types of visualisation elements have been identified (see figure 12). If the inventory had a reuse report connected to it, the visualisation elements of the report was analysed. If no report was attached to the inventory, the visualisation elements of the inventory itself was analysed. One of the visualisation elements is to use a table with scores where the different reuse potential parameters are rated. The rating of the parameters were done in two ways, either one of the ways or in a combination: • An estimated numerous value with a minumum scale of 1 to 3 and a maximum scale of 1 to 10, with 1 being the lowest. • A written comment by the different stakeholders in the project - the reuse consultant, the property developer and the architect. These kind of comments were deemed essential to determine the reuse potential, as they can get more nuanced than a single number. Figure 12. Summary of visualisation elements in the reuse reports analysed. 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply 1 2 5 1 ! Återbruk 1 Demand New construction Inventering 1 Inventering 2Återbruk 2 ex. supply Table with scores used by 5 of 10 reuse reports Table with images used by 3 of 10 reuse reports Coloured blueprints used by 3 of 10 reuse reports Diagrams used by 5 of 10 reuse reports Digital 3D model used by 2 of 10 reuse reports Idea catalogue used by 3 of 10 reuse reports Image appendix used by 4 of 10 reuse reports Table with heatmap used by 4 of 10 reuse reports PART I - REUSE TODAY SETTING REUSE TARGETS DETAIL INVENTORY The visualisation elements are an important way of summarising and comparing the reuse potentials of different buildings parts and as such, important to be able to set reuse targets. A reuse target is an overall generic goal for the amount of reuse in the project. This was used by all six reuse projects analysed in this thesis. Three types of reuse targets were identified, based on either: • a percentage, such as "85% reused building parts, measured in volume units" (Dahlstrand, personal communication, Mars 19, 2021) • a specific building part, such as "Reuse of brick facade, concrete floor elements, stainless steel sinks and steel staircase railings" (Delander-Eksten, personal communication, February 3, 2021) • a combination, such as "100% reused surface layers in one apartment" (Lunneblad, personal communication, February 3, 2021) Reuse targets can be set by both the supply and the demand project. Supply projects set targets on the amount of building parts they want to deconstruct and find further usage for. Demand projects set targets on the amount of reused building parts they want to include in their new construction. After the reuse targets are set, a detail inventory is needed to complete the previous inventories with the information needed to be able to be plan the reused building parts into a new construction. This informaton is different for each type of building part but at least includes detailed measurements, as well as different certifications regarding fire, noise and energy standards. Which detail parameters are needed to be able to design with the reused building part is further investigated in chapter 5 (see page 81 on Design with off site supply). This is to be able to generate BIM objects based on the inventory data (see chapter 3 on Information management). It is important to have set reuse targets based on the reuse potentials as a basis in the detail inventory, as it can be a time-consuming process if the focus is not sharp enough (Stenberg, personal communication, January 25, 2021). Figure 13, 14 & 15. Visualisation examples from the reuse reports analysed (White 2019, Lendager 2019, White 2019. INVENTORIES 38 "The most valuable commodity I know of is information." - Gordon Gekko, Wall Street PART I - REUSE TODAY Investigating the purpose and methods for working with information management within reuse projects, and how they relate to the architect's design process. 3. INFORMATION MANAGEMENT 4140 SYNCHRONIZING THE DATA CONNECTING REUSE TO THE DESIGN PROCESS One of the prerequisites for a circular building industry, as stated in the introduction, is that information about built-in materials and products can be stored in an accessible way. By putting the information from the inventories in standardised database systems, the data can be synchronized between stakeholders within the project as well as between projects (Göteborgs stad 2020, 17). This type of infrastructure is called a digital ecosystem, which can be described as a collaborative exchange of information (IVL 2021, 18). There are several benefits to creating digital ecosystems within the reuse process: • A better reuse market, by creating an overview of available materials and products for all buildings, at all scales and in all phases, making it easier to source components for a demand project (Andersson & Nilsson 2020, 94). • A possibility to connect with other types of information, such as product specifications and material compositions (Göteborgs stad 2020, 17). • Enabling further usage of the built-in components during property management, such as through a digital twin (IVL 2021, 4). • Enabling further usage of the data in the design process, for example by connecting it to a BIM model (Stenberg, personal communication, January 25, 2021). The overall benefit is that less time is needed for hunting down information, making it more efficient and thus more industrial (Andersson och Nilsson 2020, 94). This thesis has delimited itself from the reuse market and property management, and rather focus on the architect's process in relation to reuse. As such, this chapter will delve more into the last point - the integration of the inventory into the architect's design process using information management. There are several examples of projects using information about reused building parts as a part of the design process. This chapter uses semi-structured interviews and literature review of previous theses to analyse a selection of building projects connecting the architect's design process to the reuse of building parts. In a reuse project by Danish architecture firm Vandkunsten, the architects placed all existing and found construction elements in a 3D model from which they continuously adjusted the design (Josefsson 2019, 140). This is a common method when working with on site reuse, where the existing building and its constituting building parts need to modeled any way (Westin, personal communication, April 23, 2021). When working with large scale off site supplies however, this method of manually modeling 3D model objects that might or might not be included in the final design would be too time-consuming to be economically feasible. In their project Upcycle studios, Danish architecture firm Lendager Group developed a new product called Upcycle windows, where reused window panes were mounted together in a new frame to form a curtain wall system. As a part of the project, an algorithm was developed that took the dimensions from the inventory data of the available reused window panes and optimised the amount of them in the curtain wall system by looking for the most efficient pattern (see figure 16) (Lendager 2020, 164). This kind of tool provides a strong connection between the inventory data and the design process, and is more efficient because of the algorithm. It is however customised to solve one very specific problem of the reuse design process. Figure 16. Pattern algorithm for Upcycle windows (Lendager 2020). PART I - REUSE TODAY CONNECTING REUSE TO BIM There are lot of research papers and pilot project connecting reuse of building parts to building information modeling. These have been found via the semi-structured interviews and by searching for "reuse + BIM" in research database systems. BIM stands for Building Information Modeling and is the process of creating and managing information in a construction project through a digital representation of the building (NBS n.d.). BIM software is a software that enables the use of BIM, such as Revit or ArchiCad (BIM wiki n.d.). BIM model is all the 3D geometry of the building, and its associated information, within the BIM software. BIM object is a digital 3D representation of a specific building part in the BIM model. It is a combination of the actual object geometry and the associated information such as material and manufacturer properties (Break with an architect n.d.). BIM BIM model BIM software BIM object The relationship between different BIM definitions. The pilot project The Circular Building was as a prototype collaboration between Arup, Frener & Reifer, BAM Construction and The Built Environment Trust. The small house was designed using a BIM model which uploaded the material and component information to a database. Each material was given a so-called material passport in the form of a physical qr code, containing the information required to facilitate future circulation of the materials. The materials themselves, however, were new (Gorgolewski 2017, 57). In their project ACE - Arkitektur för cirkulär ekonomi, Sweco looked at the tools and methods needed to create architecture for a circular economy on an industrial scale (Eriksson 2019). One of their main themes is the use of BIM to include information related to circular economy, by developing a list of property sets in Revit. The property sets contain both boolean properties (yes/no), such as ComponentPrefabricated and ModularComponent, indicating if the building part is prefabricated or modular, as well as percentage-based parameters, such as ReusePotential (Eriksson 2019, 65-66). Furthermore, they connected the values from the property sets to a 3D heatmap to see which objects are connected to high or low values, meaning to visualise potential climate thieves (Eriksson 2019, 73). Similar to The Circular Building, however, this project also worked with virgin materials, and as such focus on design for reuse rather than design with reuse. This means that: • they design using virgin materials rather than reused materials • they focus on the export of data from the BIM model, rather than the import of data to the BIM model There are a few research papers that approaches the integration of existing, preused building parts into a BIM model. Cai and Waldmann propose a material and component bank to make the reuse of building parts in old building into new buildings more efficient. The research paper is however assuming that a BIM model of the old building already is existing (Cai & Waldmann 2019, 9). This is generally not the case with older buildings. INFORMATION MANAGEMENT 4342 In a 2020 research paper, Bertin et al. creates a BIM- based toolchain and database for the reuse of load- bearing steel columns and beams. In their database, BIM objects of the reused structural elements are stored along with information on the more structural properties. These reuse BIM objects can then be imported and replace new elements in the BIM model (Bertin et al. 2020, 15). The information is stored in two ways in BIM: through phasing and through shared parameters (Bertin et al. 2020, 12-13). Similarly to Cai and Waldmann, however, Bertin et al assumes that the reuse BIM objects need to be modeled manually prior to the integration into the new BIM project. One of the reuse projects analysed in this thesis is the ongoing remodeling project of Bromma Hospital in Stockholm. As a part of the renovation, a 2-year long research project led by IVL Svenska Miljöinstitutet and Kaminsky architects is investigating how to plan for and coordinate the reuse of building parts (Vectura 2020). The goal in Bromma Hospital is to try to and use the inventory data to generate BIM objects of at least some of the building parts planning to be reused, starting with some storage cabinets (Stenberg, personal communication, January 25 2021). Similarly, Sweco claims that within BIM softwares today, there are no simple ways of importing or cross- referencing information about materials - neither virgin nor reused - from and to a material database (Eriksson 2019, 80). Conclusively, what is lacking is a simple way of importing the inventory data into a BIM software to generate BIM objects that the designer can use as a part of her design process. To enable this type of function, a further analysis is needed of: • in what ways current material inventories are logged and stored • in what ways BIM software organise and visualise data • in what ways BIM objects can be generated through the import of data "In the next step of processing the inventory, compatibility with a BIM software is essential. This is nothing that is possible today, but the possibility is widely asked for from several actors in the building sector. It is a way to simplify the designing, planning and integration of reused materials in the project for the architect." (Stenberg, personal communication, January 25, 2021) Figure 17. 3D scanning as a way of logging and storing inventory data, using White Recapture (White ReCapture n.d.). PART I - REUSE TODAY Figure 18. Screen shot from one of the logging stages of an inventory in CCbuild Produktbanken (CCbuild n.d.). INFORMATION MANAGEMENT CCbuild Produktbanken As mentioned in the background chapter, CCbuild is an innovation project run by IVL Svenska Miljöinstitutet. They are providing a digital platform consisting of an inventory software and a market place for reused building parts. These two services are connected and synchronized through Produktbanken, which is a database with a user interface where users can upload the information from their inventories using a set list of parameters (see figure 18). Each inventory is connected to a specific project with a specific project owner, but the information can be shared with other project owners if needed. The inventory data can also be downloaded as an Excel sheet (CCbuild n.d.). The consequence when working with this kind of tool is to have to work with a set list of parameters, and not be able to customise the tool according to project-specific parameters. This aside, Produktbanken is providing the tool the closest to the idea of a standardised database system where inventory information can be shared between projects. To date, they have around 85 different companies and 160 projects using the database (Loh Lindholm, personal communication, May 10, 2021). Dacke App Dacke App is a private company offering an inventory software and database, with an associated phone application. The software is still under development and no testing have been possible during the time of this thesis. It does however have an API in progress to be able to connect to other platforms (read more on API on p. 45). Jan Axlund, CEO of Dacke App, deems this as essential to be able to success as an inventory tool. 'API in' is to be able to reach the information in the BIM software to see the available components in the inventory database, 'API out' is to be able to forward that information back to the original source, to "reserve" the component in the inventory database (Axlund, personal communication, January 22, 2021). As the tool is still under development, however, no further analysis or usage of Dacke App is made in this thesis. White ReCapture White ReCapture is an inventory service developed by White Architects, where the building is 3D-scanned, imported to a BIM software and converted into BIM objects (see figure 17). This makes it possible to store the building geometry directly in the BIM software and save further information directly to each BIM object, thus creating a direct integration between the inventory and the BIM model (White ReCapture n.d.). However, this type of inventory becomes very project-specific, and there is still a need for a database to upload the BIM objects to if further usage of the objects in other projects are to happen. Because the service still is very new, no further analysis or usage of White Recapture is made in this thesis. Spread sheets Using a spread sheet service, such as Microsoft Excel or Google Sheets, is a simple and accessible way of logging the data from an inventory. The parameters for each inventoried object could easily be customised by adding and deleting columns, and by using several worksheets. The spread sheet formats, such as .txt and .csv, are compatible with most tools, softwares and programming languages (Guru99 n.d.). However, it might be difficult to secure that the information is logged in the same way throughout different projects, thus decreasing the compatibility chances. LOGGING AND STORING INVENTORY DATA To understand in what ways inventory data can be used further in the design process, an analysis of how the data of current material inventories are logged and stored is needed. From the inventories analysed in this thesis, as well as the answers from the semi-strucutred interviews, four tools for logging and storing the inventories were found. 4544 PART I - REUSE TODAY INFORMATION MANAGEMENT ORGANISING AND VISUALISING BIM OBJECT DATA To understand in what ways data connected to BIM objects is organised and can be visualised, a summary of the most essential and commonly used functions were made using Revit documentation. IN WHAT WAYS CAN WE ORGANISE DIFFERENT DATA? Phasing Most building projects proceed in phases, each representing a distinct time period in the life of the project (Autodesk n.d.). In a typical renovation project, the phases would at least consist of "Existing", "Demolition" and "New construction" (Westin, personal communication, April 23, 2021). Revit tracks the phase in which views or elements are created or demolished. Phase filters can then be used to produce phase-specific project documentation, controlling what elements are visible in what phases (Autodesk n.d.). Families A family is a group of elements with a common set of properties (family parameters). Different elements belonging to a family may have different values for some or all of their parameters, but the set of parameters (their names and meanings) is the same. These variations within the family are called family types or types (Autodesk n.d.). Parameters Parameters store and communicate information and properties about all elements in a model. They are used to define and modify elements. There are four types of parameters: Project parameters specific to a single project file, usually used to categorise views. Family parameters specific to a family, such as the dimension of a door. Shared parameters can be used in any project or family because it is saved in a separate file. Global parameters specific to a single project file, usually used to set specific values or dimensions between elements. (Autodesk n.d.) IN WHAT WAYS CAN WE VISUALISE DIFFERENT DATA? Tags A tag is an annotation for identifying elements in a drawing. When a tag is created, labels are added to display the value of desired element parameters (Autodesk n.d.). Schedules Schedules are tables that can be used to quantify and analyse the amount of components and materials in your BIM model. They can be filtered to only show BIM objects with certain parameters or parameter values. The schedules can also be exported in various standardised formats such as .txt or .csv (Autodesk n.d.). View filters A view filter can be used to override the graphic display and visibility of selected elements that share common parameters (Autodesk n.d.). BIM COMPATIBILITY TOOLS AND METHODS This chapter looks at what different types of tools or methods that can be used to generate BIM objects from imported data. The foundation of a digital eco-system relies on interoperatibility, meaning that two or more systems can both share and use the information they give and receive (IVL 2021, 21). One of the fundamental services for a well-functioning digital ecosystem is a well- functioning API (SnapLogic 2019). An API is the piece of programming defining how two or more software programs can interact. One software can call the other software's API to get access to their data, and the other way around (RapidAPI n.d.). Revit API The Revit API can be used to create software extensions or plug-ins that provide further functions than the original software. The plug-ins are a part of the Revit interface. These plug-ins can be written using a variety of programming languages, such as C# and Visual Basic. The Revit API documentations is a manual providing all the information and code references needed for the developer to create a plug-in (Autodesk n.d.). However, to work with the Revit API means that the developer of the plug-in needs to have programming skills, making it less accessible and prone to updates, changes and development by the actual plug-in users - professionals in the construction industry. Visual programming Visual programming is a type of programming language that lets the user describe the programming processes using illustrations and flow charts, where each illustration represent an already defined piece of code (OutSystems 2019). This type of programming requires less text-based programming experience, meaning it is a lower threshold for a professional in the construction industry to go in and develop the functions of the plug- in according to her preferences. There are two visual programming languages compatible with Revit: Dynamo and GrasshopperInside.Revit. Both of these can create and edit a majority of the Revit elements, including families, family types and their associated parameters (Rhino.Inside.Revit n.d.). Existing plug-ins In the AutoDesk App Store, Revit users can browse through thousands of existing plug-ins. There are several plug-ins enabling the user to download and thus generate BIM objects directly into the model from the plug-in's database of BIM objects. One of the most popular examples is NBS National BIM Library, a British company that has developed a BIM object standard for product manufacturers to follow to ensure compatibility and consistency for the user (NBS National BIM library n.d.). Another example is bimproject.cloud, a web-based catalog of BIM objects where the user can create and customise their own objects by changing the parameters before downloading the objects, see figure 19. A customised object is always based on an existing family type in the database, which the plugin duplicates and changes the properties according to your settings (bimproject.cloud, n.d.). There are also plug-ins allowing the user to import and export data in various format into Revit. The AutoDesk App Store review does however not show any plug-ins allowing the combination - to generate BIM objects based on imported data, and upload the altered object back. Figure 19. Screen shot from bimproject.cloud, where the user can customise their BIM object before downloading it (bimproject.cloud, n.d.). 46 "If you want to be a good archeologist, you gotta get out of the library!" - Indiana Jones PART I - REUSE TODAY Summarising and discussing the findings from chapter 1, 2 and 3. 4. DISCUSSION 4948 DOING THE RIGHT THING AT THE RIGHT TIME ON SITE & OFF SITE SUPPLY 1. The project is a remodelling project where building parts can be reused from the same project, meaning an on site supply. 2. The project is a new construction and has to search for reused building parts from an off site supply. If the project has an on site supply, it means that the building parts are known from the start and can be planned into the project as soon as all necessary inventories have been performed. When using one or several off site supplies, an Urban mining is done to get a first understanding of the general availability of certain building parts. The Urban mining is done at an early stage in the project and consequently, the design have to be planned with flexibility. The specific building parts from off site are settled later in the project to avoid unnecessary storing. The analysis of ongoing reuse projects shows that the reuse process has to be performed differently depending on two different scenarios connected to the orgin of the supply. The analysis of reuse projects and inventories shows the importance of starting at an early stage in the building process, but more importantly to do the right thing at the right time. PART I - REUSE TODAY Environmental inventory Reuse potential inventory Detail inventory Urban mining Environmental inventory Reuse potential inventory Detail inventory Urban mining Environmental inventory Reuse potential inventory Detail inventory Urban mining Environmental inventory Reuse potential inventory Detail inventory Urban mining Figure 20. The inventory funnel. DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED Reuse targets PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION PROGRAMHANDLING SYSTEMHANDLING DEMOLITION PROCUREMENT DECONSTRUCTION BYGGHANDLING CONSTRUCTION SUPPLY PROJECT SUPPLY SUPPLY DEMAND PROJECT DEMAND DEMAND USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION FLOW OF BUILDING PARTS & INFORMATION BUILDING PARTS FLOWINFORMATION FLOW (INVENTORIES & INFORMATION MANAGEMENT Design with on site reuse targets DEMOLITION PROCUREMENT DECONSTRUCTION INVENTORIES PERFORMED Reuse targets PROGRAMHANDLING SYSTEMHANDLING BYGGHANDLING CONSTRUCTION PROGRAMHANDLING SYSTEMHANDLING DEMOLITION PROCUREMENT DECONSTRUCTION BYGGHANDLING CONSTRUCTION SUPPLY PROJECT SUPPLY SUPPLY DEMAND PROJECT DEMAND DEMAND USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION USE & MAINTANANCE DECONSTRUCTIONCONSTRUCTION FLOW OF BUILDING PARTS & INFORMATION BUILDING PARTS FLOWINFORMATION FLOW (INVENTORIES & INFORMATION MANAGEMENT Design with on site reuse targets An early and clear priority of what building parts to reuse makes the process more efficient and simplifies further work. Here, we can compare the reuse projects Stadskvarteret and Bromma Sjukhus. At Stadskvarteret, a reuse potential inventory quickly narrowed down the reuse targets to brick, stainless steel kitchen sinks and staircase railings. These were then successfully detail- inventoried, deconstructed and reused (Delander-Eksten, personal communication, February 3, 2021). At Bromma Sjukhus, the detail inventory was done too early, meaning that the reuse consultant put a week just on inventoring doors, without even knowing if they were going to reuse them (Stenberg, personal communication, January 25, 2021). The conclusion from the Hoppet inventory shows the importance of starting the reuse process with an environmental inventory, to avoid unnecessary work. An analysis of the reuse projects show that only 3 of 7 actively used the environmental inventory in their reuse process. Furthermore, a reuse project could benefit from performing the environmental and reuse potential inventory at the same time. There is no point for both an environmental consultant (using quantitative/objective methods) and a reuse consultant (using qualitative/ subjective methods) to count windows - this should be done by one of them, and then the information could be shared with the other. As an example, the environmental inventory consultant counts windows and check their asbestos level, while the reuse consultant check the quality, disassembly feasibility etc. To summarise these findings, the four different steps of doing inventories can be combined into an inventory funnel (see figure 20) where inventories are performed in a specific order depending on the scale and phase of the project. The funnel highlights the importance of doing the right type of inventory in the right order and at the right time, to make the process more efficient and less time-consuming. How "initial" or "detailed" an inventory is, as described in figure 8 on page 28-29, is mainly based on: • the number of inventory data parameters • the detailing of each inventory data parameter (e.g. quantity is a less detailed parameter than measurements) How detailed an inventory can be, is mainly based on: • the project scale • the reuse priorities (many different types of building parts = less detailed inventory) VISIBILITY & COMPATIBILITY An inventory contains a lot of information that can be difficult to get an overview of in its raw format. A reuse report summarising the most important findings from the inventory, including the use of visualisation elements, has proven efficient to keep the different stakeholders in the project informed. As mentioned in chapter 3 on Information management, this type of visibility would be useful to incorporate in a BIM model for a continous and updated version of the information, available at all times. One of the prerequisites identified to make the reuse process more industrial is the need to connect the information from the inventories. The information needs to be connected in-between the inventories themselves - to save time and work hours - but also connected to further usage in the building project. This requires compatibility - a standardised way of logging, organising and storing the data as well as an API for uploading and downloading the data. The development of an API is outside the scope of this thesis, but for the pilot project in the next chapter, ways of testing and developing both the visibility and the compatibility of the inventory data will be done through the use of a BIM software. The research made in chapter 1 and 2 highlighted two key words that can be used to summarise the most important functions of inventories and information management: visibility and compatibility. DISCUSSION Urban mining - An inventory to understand what exists to reuse Environmental inventory - An inventory to sift out what is possible to reuse R