Circular Economy has been highlighted internationally as a solution to mitigate global warming. This study examines the reuse potential of precast concrete elements in Swedish residential buildings, quantifying its impact on element flows and stock using life cycle assessment. While reuse achieves higher carbon savings than recycling, the overall impact remains modest due to limited demolition and high demand for new materials, with most precast concrete elements still embedded in the stock. Assuming all deconstructed elements are reused, savings reach up to 1 % of lifecycle emissions, with a proportional relationship observed between reuse share and embodied carbon savings. Despite aligning with IPCC recommendations for increased prefabrication, the growing precast concrete intensity in buildings with precast concrete structure reflects rising resource consumption. Further studies should assess how technological advancements affect life cycle impacts and reuse feasibility, while also exploring reuse in non-residential buildings and policy measures to strengthen circular economy strategies.

The ReCreate project researches deconstruction and reuse of precast concrete elements, not originally designed for disassembly. Real-life deconstructions of precast concrete buildings in four countries (Finland, Sweden, the Netherlands and Germany), performed by ReCreate’s industrial partners as well as collaborators to harvest elements for reuse, were a key tool to gain experience and insights into deconstruction techniques and processes. The current report delivers an overview of what deconstruction entails. It gives best practice guidelines on the planning and implementation of deconstruction, as well as recommendations for improving the process.

While ReCreate’s country-specific deconstruction pilots themselves are described in a dedicated report (Vullings et al. 2024), they are also briefly summarised in the beginning of this report. The focus of the current report is, nevertheless, on turning the learnings from deconstruction pilots into generalisable guidelines that can be capitalised beyond the ReCreate project and the parties involved.

Deconstruction entails four main phases: pre-planning, structural deconstruction planning, deconstruction work planning, and finally, implementing the deconstruction. This report instructs on the different types of plans involved in each stage as well as their authors and contents.

Pre-planning involves pre-deconstruction auditing, i.e. inventorying reusable elements and gathering relevant information into an ‘inventory’ Building Information Model (BIM). The pre-deconstruction audit has been covered by another ReCreate deliverable (Vullings et al. 2022), which was delivered before ReCreate’s deconstruction pilots were fully complete. Therefore, the current deliverable briefly recaps the essentials of a BIM-based pre-deconstruction audit, and supplements and consolidates the findings of the previous report.

Authored by a qualified structural engineer, a structural deconstruction plan sets the foundations for a safe and efficient deconstruction process. It defines the deconstruction sequence based on structural stability; determines the need for temporary support and bracing measures; establishes cutting spots for connectors; gives a labelling scheme for logistics; instructs on correct lifting and transport of elements, as well as how to monitor the quality of elements on-site; and can help to define requirements for stripping.

A deconstruction work plan, devised by experts of the deconstruction company, translates the structural deconstruction plan into work processes: both the overall deconstruction process as well as element type specific processes. It covers aspects like workforce, equipment, work safety, site planning, and scheduling.

Finally, learnings acquired by implementing ReCreate’s deconstruction pilots are elaborated on. Findings are reported on deconstructing different types of elements; avoidable mistakes that were made which may influence the reusability (or at least the effort and cost of reuse) of the salvaged elements; the types of damage that is not easily preventable but an inherent part of deconstruction; and the influence of weather conditions on the deconstruction work. Additionally, special types of deconstruction projects are briefly discussed, such as partial deconstruction in the context of building remodelling, as well as combining deconstruction with conventional demolition.

While smaller, sub-process specific insights are scattered through the report, the main learnings of the key topics are distilled into checklists, given at the end of this report. The experience of the ReCreate deconstruction pilots shows that prerequisites for more widespread deconstruction already exist in that appropriately skilled workforce and suitable tools and equipment are widely available. The main technical and processual challenge in deconstruction is reconfiguring the existing know-how into safe and efficient deconstruction processes. This development can be further supported by small adjustments to existing tools that can help make the equipment even better suitable for deconstruction purposes. Nevertheless, it should be noted that a full evaluation of the success of ReCreate’s deconstruction pilots can only be made once the salvaged elements have been reused in new buildings.

The ReCreate project researches deconstruction and reuse of precast concrete elements, not originally designed for disassembly. ReCreate’s real-life pilots are a significant tool for achieving this goal. This report describes and illustrates ReCreate’s deconstruction pilots.

Six real-life deconstructions of precast concrete buildings – one in Finland, two in Sweden, one in the Netherlands, and two in Germany – are used in the ReCreate project to generate theoretical and practical knowledge about a wide range of topics directly related to the process of salvaging and reusing precast concrete elements. While the learnings regarding the planning and implementation of deconstruction are described in a centralised manner in another report (Vullings et al. 2024), the current report documents the donor buildings of the secondary elements as well as their practical deconstruction processes through textual descriptions and generous photographic illustrations and drawings. The donor buildings were blocks of flats (three buildings), public and private office buildings (two buildings) and industrial/warehouse buildings (one building). They had been deemed obsolete and were therefore slated for demolition. When engaged in ReCreate, they instead became vessels of knowledge generation for reuse-minded deconstruction. The various elements reclaimed from the donor buildings, such as sandwich panels, massive concrete slabs, massive interior wall elements, hollow core slabs, beams, and columns, will be reused in future in ReCreate’s reuse pilots. In addition to ReCreate’s six donor buildings, insights from following and observing two additional deconstructions, external to ReCreate, are also reported on herein.

Bygger vi en blandad stad? Kartorna sompresenteras här ger en tydlig och empirisk bild övereffekterna av nyproduktionen av flerbostadshus iStockholmsregionen år 2017.

Architecture's footprint on the planet is not so easy to undo. However, some cases allow it. This research/action project looks for those concrete buildings that can be disassembled - instead of demolished - so that its parts can be recovered in search of future reuse. Thus, what once was pure waste can have a new life.

Industrial building in 2020 is far muddier and more complex than expected. This catalogue is a study and mapping of contemporary structural systems in Sweden right now. Mapping actors in the building industry, including developers, factories, architects, organizations and companies, displays a motley array of methods and processes for building millions of homes for Sweden’s growing population. But do they provide good housing for the masses? Studying the material compositions of structural systems as well as recent building permits in the Stockholm region over the past couple of years reveals a taxonomy of how mass housing has implemented industrial building methods, but not always as expected.

Is it time again to collaborate more and share the knowledge of structural building systems in order to have a more efficient production apparatus? Former KTH researcher and engineer Peter Adler speculated on the fourth generation of industrialized building, a conceptual understanding of efficient building production in which sharing of platforms, concepts and processes would advance. This, in turn, would encourage and support an adaptability to diversity in terms of living conditions as well as changes in local and regional conditions for development. 

We wanted to grasp this potential in industrialized building by continuing the trajectory of understanding tectonics with regards to materials (concrete, wood, steel, and composites) and scales of elements (from small-scale such as beam and lintel construction to a middle-scale of prefabricated elements and large-scale in prefabricated volume elements). Therefore, we developed a categorization loosely based on Constructing Architecture, Material Processes Structures: A Handbook (Andrea Deplazes, Ed.) and the writings of Kenneth Frampton, although the historical tracing of this study has a deeper and more explicit ambition to map structural systems.

Flygande betong handlar om världens mest spridda byggsystem: det prefabricerade betongelementet. Det är också en bok om hur denna innovation blev ett viktigt verktyg när ett helt nytt samhälle skulle formas. Efter andra världskriget har prefabricerade betongelement bidragit till att drastiskt förändra tekniken vi bygger den moderna världen med. I deras spår kom automatiserad massproduktion att ersätta det tunga kroppsarbetet på byggplatserna och med de nya betongelements hjälp kunde den växande befolkningen i världen förses med miljarder kvadratmeter bostadsyta. Arkitekturen från betongelementens guldålder har blivit synonym med tristess och monotoni och byggnaderna från tiden hånas som fula och omänskliga. Men under andra hälften av nittonhundratalet var den heroiska bilden av ett flygande betongelement vanligt förekommande i allt från målningar, foto, teckningar och film till affischer, serier, leksaker och operakulisser. I Flygande betong har en grupp arkitekter, historiker, filosofer och curatorer förenats för att analysera hur betongelementet fick global spridning. Boken tecknar byggteknikens kulturhistoria och begrundar betongelementens påverkan på såväl våra städer som kulturen från andra halvan av nittonhundratalet fram till idag.Utgiven i samband med ArkDes utställning Flygande betong (18 oktober 2019 – 1 mars 2020), kurerad av Pedro Ignacio Alonso och Hugo Palmarola. Bidrag av Michael Abrahamson, Jimena Castillo, Adrian Forty, Boris Groys, Maria Lind, Jennifer Mack, Philipp Meuser, Natalya Solopova, Erik Stenberg och Christine Varga-Harris.

Bakgrund: Hur hamnade vi här (sid 16-28)

av Carl-Johan Engström, Kristian Skånberg och Erik Stenberg

Byggandet utgör en stor delav de svenska samhälleligainvesteringarna. Boendet ståri sin tur för den enskilt störstaposten i de flestas hushållsbudget.Detta gör att det sammantagethandlar om mycket stora pengaroch resursflöden kopplade tillhållbarhetsfrågor. Det rör ocksåde miljöer där de flesta människortillbringar merparten av sina liv,med alla de beröringspunkter kringsocial hållbarhet som detta för medsig. Det gör förändringar mycket angelägna.

Byggandet: Kolsänka och energiproducent

av Victoria Kalén och Erik Stenberg (sid 55-61)

Bygg- och fastighetssektorn stårför en stor del av samhälletsutsläpp av växthusgaser. År 2015var de inhemska utsläppen avväxthusgaser ca 11,1 miljonerton koldioxidekvivalenter. Detmotsvarade 18 procent av Sverigestotala utsläpp av växthusgaser.Lägger vi till utsläppen som byggochfastighetssektorn genererarutomlands så blir totalen över 20miljoner ton koldioxidekvivalenter.Boverkets miljöindikatorer visaratt bygg- och fastighetssektornsmiljöpåverkan ökat ytterligaresedan dess. Dessutom kommervia de globala varukedjorna förbyggmaterial ytterligare uppemot 10miljoner ton koldioxidekvivalenter ini den svenska byggprocessen årligen.Ur ett konsumtionsperspektiv äralltså de byggrelaterade utsläppenännu högre.

Hela rapporten:

En ny plattform för att lösa bostadsfrågan är en antologi skriven av sex författare i samråd med Global Utmanings programråd för Hållbara Städer. Antologin tar avstamp i bostadsfrågan ur ett historiskt perspektiv och belyser frågan utifrån den gemensamma strategin för en hållbara omställning – Agenda 2030. Plattformen hanterar en såväl ekonomisk, som social och miljömässig omställning av ”bostadsfrågan”, det vill säga boendet, byggandet och stadsutvecklingen. Antologin innehåller dels förslaget till plattform för samverkan och dels fem bidrag som konkretiserar problem och utmaningar.

I rapporten Arkitektens roll: Bostadsritande arkitekter i Stockholmsområdet presenterasresultatet av intervjuer med arkitekter som ritat flerbostadshus med beviljade bygglov iStockholms kommun år 2014. Studien utgår ifrån bostadsfrågan och ligger inom ArkDesuppdrag att stärka och vidga arkitektens roll. Syftet med studien är vidare att kartlägga och analysera på vilket sätt praktiken löser sina behov av kunskap och på vilka sätt dettabreddar arkitektens traditionella roll. Studien har utförts av Erik Stenberg på KTH undervåren 2019 och presenteras på ett seminarium på ArkDes 27 augusti 2019 tillsammansmed den parallellt framtagna rapporten Arkitektens roll: Forsknings􀀐nära arkitekter i Stockholmsområdet av Anna Sundman, Theory Into Practice.

Under mars och april 2019 genomfördes femton entimmes intervjuer med bostadsritandearkitekter i Stockholmsområdet. Tillsammans med den intervju som gjordes i oktober2018 bildar dessa sexton intervjuer med knappt trettio arkitekter det huvudsakligaunderlaget för föreliggande rapport. Valet av arkitekter utgick från det dryga femtiotalbygglov som finns redovisade i Bygglovsboken: Flerbostadshus 20144. Dearkitekter/kontor som ritat dessa bygglov utgör ett tvärsnitt av små och stora etableradearkitekturpraktiker i Stockholm. Att kunna genomföra och få beviljat ett bygglov för ettflerbostadshus i Stockholm är kvalificerat arbete som inte minst kräver kunskap,kompetens, kapacitet och kontakter. Eftersom byggloven beviljades för flerbostadshus iStockholms kommun år 2014 var de flesta husen uppförda vid intervjutillfället ochdärmed kunde arkitektens roll i hela processen beaktas.