Design for disassembly and adaptability: why it matters
By 2050, another 2.5 billion people are expected to live in urban areas. To accommodate these people and meet their needs, it’s estimated that buildings and infrastructure equivalent to a city the size of Milan (1.5 million people) will need to be constructed every week until 2050. As a result, it’s critical that the construction of necessary new buildings involves less resources, uses more reused and recycled materials, and reduces the need for demolition and further construction in the future.
Two circular construction approaches that can play a key role in achieving these goals are design for disassembly and design for adaptability:
Design for disassembly (DfD) is an approach to planning and designing a building so it can be easily dismantled. This allows the building to be moved or for components to be directly reused in other projects in the future.
Design for adaptability (DfA) is an approach to planning, designing and constructing a building so it can be easily maintained, modified and used for multiple purposes throughout its lifetime, extending its practical and economic lifecycle.
DfD and DfA can help cities meet their housing and infrastructure needs while ensuring circularity in the future
These two approaches can be broken down further into:
Multifunctionality – being able to adapt a space for different use or needs without any disassembly of components.
Transformability – being able to reconfigure and adapt an internal or external structure through partial disassembly of components to suit different use or needs.
Demountability – being able to fully disassemble a space and its components so that they can be reused or recycled elsewhere.
When a new building is designed and constructed using DfD and DfA, it could solely focus on multifunctionality, transformability or demountability, or it may involve a combination of these practices.
Historically, DfD and DfA approaches have been used for centuries. Yet DfD and DfA are not mainstream in the construction industry today, despite the technical solutions needed to carry them out already existing. This lack of adoption is mainly due to the fact that these solutions come at a slightly higher upfront cost in monetary, carbon and material terms compared to conventional construction.
Looking to the future, it’s vital that decision makers and building environment professionals think beyond short-term gains and take action that will help to meet long-term climate goals. As shown in this chapter, DfD and DfA can help cities meet their housing and infrastructure needs while ensuring circularity in the future. These approaches will help cities minimise waste, reduce carbon and save money by keeping materials, components or entire buildings in use for longer.
What does design for disassembly and design for adaptability look like in practice?
Working with each other and local built environment stakeholders, partner organisations in the four CIRCuIT cities developed and evaluated 12 demonstrator projects to showcase design for disassembly and adaptability strategies and the benefits they can deliver. 4 are showcased here.
Twelve of these demonstrators – three in each city – showcased a broad range of DfD and DfA approaches that could be applied to mainstream construction, highlighting opportunities and potential challenges. Below is one demonstrator project from each of the four CIRCuIT cities. Please note that some of these demonstrators were built while others remained concepts.
Full overviews including detailed carbon and cost assessments of all demonstrators can be found at circuit-project.eu/post/latest-circuitreports-and-publications
In Copenhagen, new residential buildings tend to be designed to the same specifications. In fact, 66% of apartments have three rooms and the floor area of the flat is between 85–115m2, not including outside areas such as storage space, a balcony, etc.
Currently, prefabricated concrete construction with loadbearing walls are the norm in Danish construction. In this approach, structural concrete elements are cast together to form internal and external walls and floor slabs. However, this limits flexibility, both horizontally and vertically, and the structural elements are difficult to modify without major interventions. Services like underfloor heating, drainage and electricity are often integrated into the concrete. This makes them difficult to access for maintenance or replacement without demolishing part of the structure.
Projections show an increasing need for smaller one and two-room apartments in Copenhagen. But because of the way Danish buildings are currently constructed, it’s unlikely a simple layout shift alone could meet future demands. This means buildings are at risk of being prematurely demolished in favour of new dwellings.
DfD and DfA approach
The adaptable housing demonstration project in Copenhagen aimed to show how apartment blocks that use DfD and DfA principles could meet future housing demand and deliver significant environmental and economic benefits.
The demonstrator showcased an alternative structural system based on frame construction. It included a frame system without loadbearing walls. Slabs could be removed to significantly increase adaptability, both horizontally and vertically.
In addition, including mechanical fixings and lime mortar instead of cement allowed components to be dismantled. Design enabling disassembly of building layers, avoiding cast-in services and replacing concrete screed with sand enabled services to be replaced or maintained easily without major interventions.
The demonstrator also included standard prefabricated elements such as concrete columns, concrete core, steel beams and hollow core slabs.
Compared to a business as usual (BAU) case study, the DfD and DfA approach had a substantially higher reuse potential (85%).
Results also indicated that the embodied carbon of the BAU approach and the DfD and DfA approach were almost the same after a single building lifecycle. However, if the DfD and DfA buildings were redeveloped, there would be an embodied carbon saving of 37% after the first redevelopment and 50% after the second.
Constructing the alternative buildings and disassembling them would be 25–28% more expensive than using the BAU approach and demolition. However, if the alternative buildings were redeveloped, there would be a 27% cost saving after the first development, and 45% after the second.
Adopting DfD and DfA principles may require a higher upfront investment, but by extending the lifecycle of a building and its elements, there can be substantial environmental and economic benefits after just one redevelopment.
The Klassenhäuser structure – slab construction
In Hamburg, several schools were built using comparable design concepts. This demonstrator aimed to compare the impact of conventional construction floor slabs against three DfD versions.
DfD and DfA approach
The BAU case for this design was a conventional floor slab made using an in-situ concrete method. Three different types of DfD floor slabs were made using pre-stressed concrete cast elements, pre-stressed concrete cast elements with seam and joint and a bolted timber-concrete construction method to aid disassembly and reuse.
The demonstrator found that the DfD slabs could be dismantled completely and sorted by material type. The DfD floor slabs used 40% less concrete, representing significant material savings and associated carbon impacts. Additionally, the DfD slabs interlocked, which meant, unlike traditional methods, no gaps needed to be sealed.
Using the pre-stressed concrete slab with seam and joint did result in dimensional differences. The DfD school building was 50cm higher than the comparable BAU building, which affected wall heights, staircase and railing lengths, pipe lengths and the distance between the building’s columns. These had to be reduced, resulting in more columns and fewer open spaces, which is a drawback that would need to be considered when weighing up the benefits of using this method.
Overall, the demonstrator showed that using DfD slabs could lead to a 70% cost saving over multiple lifecycles of the building, as well as significant carbon savings.
Design for disassembly warehouse
Traditionally, warehouses are designed to remain in a fixed location, be in use for around 20–40 years, then demolished, typically a long time before their technical lifespan is complete. Demolition is more likely to occur because of economic redundancy than technical limitations.
DfD and DfA approach
A single-storey steel framed DfD warehouse was designed that could be dismantled and reused in another location. The warehouse used demountable concrete foundations to allow for disassembly. All connections in the steel and concrete structure were bolted. The columns were also given the option of variable heights, allowing the warehouse hall to be either 5 metres or 3 metres tall. This DfD warehouse was then compared to a conventionally built warehouse in terms of environmental and economic impact.
Almost 100% of the DfD warehouse materials could be reused or recycled at the end of life.
Lifecycle assessment (LCA) calculations showed that over three lifecycles (relocating the DfD warehouse compared to building a new conventional warehouse) there were carbon savings of around 40%. Over two lifecycles, calculations showed that the DfD warehouse had significant cost savings, and over three lifecycles the cost saving was 41%.
Overall, it was found that applying DfD methodologies to a warehouse can be challenging because of compliance with regulations for factors such as loads, fire class and building purpose. This challenge should be taken into account in the early stages of DfD design.
Albion Street (The Hithe) – Flexible temporary building
In London, some local authorities have small parcels of centrally located but underused land that currently only host low-value uses such as storage. To trial new uses for the space, ‘meanwhile use’ construction can be valuable to provide amenities for residents.
DfD and DfA approach
A two-storey affordable office building was designed and constructed using DfD and DfA principles. The building was intended to be disassembled and relocated after 10 years, due to the lease terms for the land it was built on.
The DfD and DfA design was compared against a BAU case study in terms of its environmental and economic impact. A key difference between the two designs was that the DfD and DfA design used modular demountable structural insulated panels (SIP). The BAU design used a traditional steel frame with low-tech timber rainscreen cladding.
The economic impact assessment found that the DfD and DfA approach resulted in a 6% increase in construction cost compared to the BAU approach. However, there was a 23% reduction in overall whole life costs.
The results of the LCA study showed an initial 6% increase in whole-life embodied carbon over the BAU base case after the initial construction and use cycle. After the first redevelopment cycle, there was a 30% overall saving in whole-life embodied carbon against the BAU case study. After the second redevelopment cycle, this increased to an overall saving of 46%.
The demonstrator showed that its lifetime could be prolonged by at least 30 years. This was a 200% increase over the BAU case study. It is based on a functional need (use cycle) of 10 years and an ability to accommodate at least two additional use cycles.
The demonstrator targeted a 100% demountable design. However, general wear and tear will likely lead to replacement of materials in a redevelopment. Therefore, a waste allowance of 5% loss during disassembly and 5% loss due to wear and tear was assumed. This means 90% of the building elements for the DfD and DfA approach are estimated to be demountable/reusable.
Embedding design for disassembly and design for adaptability in the heart of cities
Guides and tools to help policymakers embed DfD and DfA approaches in future city strategy, planning policy and city-led projects are lacking. CIRCuIT partners across Copenhagen, Hamburg, Vantaa and London worked with city officials and built environment stakeholders to develop a DfD and DfA Circular Building Roadmap for each of their cities. These roadmaps outlined the best starting point towards DfD and DfA in each city and can serve as inspiration for other cities looking to embed DfD and DfA approaches in their actions.
Following the development of the four roadmaps, CIRCuIT partners identified that roadmaps are usually best integrated into or used for steering existing tools, policies or other roadmaps. If the roadmap remains a standalone resource, it may receive less attention and be less effective.
To make a roadmap a viable tool, it’s essential that stakeholders know it exists. Therefore, the roadmap must be promoted to those who can integrate it into existing practices and other tools.
Below, two approaches for a DfD and DfA Circular Building Roadmap are shared. The first is for Copenhagen and features city-driven actions. The second is for London and features design-focused actions.
Complete roadmaps for all four CIRCuIT cities are available in the report D6.5 Four city case roadmaps for implementation. Download it at circuit-project.eu/post/latest-circuit-reports-and-publications
Copenhagen DfD and DfA Circular Building Roadmap: Defining the city’s role
Copenhagen is a rapidly growing city. Its municipal plan for 2019 to 2030 proposes the construction of 60,000 new dwellings (around 4.4 million m2). Meanwhile, around 32,000 dwellings are being demolished across Denmark, primarily within the social housing sector.
Most of these dwellings were constructed between 40–50 years ago and their structural materials are still technically sound. The reasoning behind the demolitions is a complex social, political and urban planning issue. However, the fact remains the premature demotion of the dwellings will result in an enormous amount of carbon and materials being wasted.
Using learnings from the CIRCuIT project, there’s a great opportunity to influence the approach to the thousands of new dwellings being constructed in the city. The local authority is restricted in the criteria it can set for private developers to increase DfD and DfA. However, it can influence dwellings within the social housing scheme and dwellings built on municipal land.
Of the 60,000 dwellings to be constructed up to 2030, 15,000 (25%) will be social housing. Of these, 8,500 (around 567,000m2) will be delivered by 2030. The steps outlined in the roadmap below put the milestones in place that will increase DfD and DfA within social housing and highlight the city’s role in embedding DfD and DfA. The result will have a significant impact on the future circularity of the city.
Actions for implementing Copenhagen’s DfD and DfA Circular Building Roadmap
Develop principles and tools for implementing DfD and DfA in social housing
Step 1 – Outline a ‘cost pyramid’ of use cases that could deliver DfD and DfA in social housing
Use cases outlined a specific situation in which DfD and DfA approaches could add value. These use cases could then be classified in a ‘cost pyramid’ ranked with cost neutral uses cases at the bottom to more expensive ones at the top. Professionals could then decide which to use, depending on the project.
Step 2 – Develop design criteria and tools for DfD and DfA in social housing
These included guidance on DfA and DfD integration in maintenance plans for social housing and structural, fire and acoustic impact and considerations.
Step 3 – Develop procurement criteria and tools for DfD and DfA in social housing
Circular procurement guidelines have been developed in Denmark. The criteria focuses on a specific percentage target by weight for DfA. Project teams were invited to propose solutions to achieve that target within the budget.
Develop and agree on financial models and incentives for DfD and DfA in social housing
Step 1 – Agree methodology to integrate DfA and DfD in lifecycle costing (LCC)
All social housing in Copenhagen requires a lifecycle cost analysis. But this doesn’t cover factors like reuse and adaptability as ways to reduce costs for a building’s lifecycle. As a result, a new methodology should be developed covering elements like deconstruction, transportation and adaptation costs.
Step 2 – Investigate integration of LCC in budget allocation and funding for social housing
Budget allocation for social housing is based on a fixed upfront cost, plus a fixed percentage to cover future maintenance and replacement. There’s currently no way to increase budget for upfront costs, even if it means savings over the life of the building. Changing this is complex and requires a specialist group to influence funding.
Step 3 – Develop circular financial models for social housing
Based on use cases, there’s huge potential to develop new circular financial models for social housing. This could include portfolio-based renovation strategies with material flows between assets. Once tools are in place, financial models should be developed by social housing developers and promoted by Copenhagen Municipality.
Create a city strategy to support DfD and DfA in social housing
It is crucial that the city of Copenhagen communicates its ambitions relating to circularity in housing to inspire change in the industry. A city strategy can help achieve this.
Step 1 – Create and promote a vision for DfD and DfA in social housing
As part of the city vision, it is suggested to include targets for DfD and DfA amongst new construction and for the city to also develop ‘future use’ scenarios of development areas which might see a change of use in the coming 50-100 years.
Step 2 – Develop pilot projects and showcase to engage industry
Copenhagen Municipality has the potential to support pilot projects through funding, but also by leading the projects in areas where they are the developer alongside social housing associations. Two areas suitable for pilot projects have been identified: By Strømmen and Gammelby.
London DfD and DfA Circular Building Roadmap: Applying DfD and DfA principles to modern methods of construction (MMC)
London has an Affordable Homes Programme (2021–2026) with £4 billion funding to support local authorities and registered providers of social housing to deliver new affordable homes. Projects in London funded through the Affordable Homes Programme must maximise their use of modern methods of construction (MMC). A quarter of all buildings delivered through the programme must use some form of MMC.
The Greater London Authority (GLA) and Be First, the London Borough of Barking and Dagenham’s development company, have convened a Buyers’ Club to support delivery of high-quality sustainable homes. Its members are largely recipients of funding under the Affordable Homes Programme.
A primary instrument of the Buyer’s Club collaboration is a Housing Pattern Book. It provides guidance on designing apartment blocks up to 10 storeys while using design for manufacture and assembly (DfMA) principles.
The main focus of the roadmap for London is to drive demand for MMC and circular construction by influencing the construction approaches and procurement processes of Buyers’ Club members. This will primarily be done by suggesting changes in future iterations of the Housing Pattern Book and engaging with supply chains. The steps below emphasise the role that industry can take in promoting and embedding DfD and DfA within cities.
Actions for implementing London’s DfD and DfA Circular Building Roadmap
Facilitate greater consideration of full building lifecycle
Step 1 – Set direction of travel
Normalise the consideration of disassembly by adjusting terminology in the Housing Pattern Book and, in due course, in the wider industry. Ensure design teams consider circular economy design principles and approaches by requiring the preparation of circular economy statements across Buyers’ Club developments.
Step 2 – Assess the value of circular economy strategies over a building’s lifecycle
Given that councils often hold a long-term interest in sites that they develop, make investment decisions based on lifecycle costing (LCC) in preference to capital cost alone.
Step 3 – Digitise information on assets
Being ‘digital first’ helps make it easier to effectively use and manage building assets through their lifecycle. Tools like material passports (a digital document listing all the materials that are included in a product or construction during its lifecycle) help make DfD and DfA simpler.
Drive appropriate application of circular principles
Step 1 – Design for internal flexibility
Needs of residents and the city’s housing mix may change over time. To improve the chances of buildings continuing to meet housing needs, consider the potential for flexibility in apartment sizes and layouts.
Step 2 – Design for adaptability
Changes to demand on building stock are very difficult to predict. However, measures like extra structural capacity, e.g. allowing storeys to be added, will help buildings to adapt.
Step 3 – Design for disassembly
Designing for disassembly helps maximise the reusability of a building’s components at the end of its lifecycle. Shorter life building elements should be removable and replaceable.
Step 4 – Set key performance indicators (KPIs) at a building level
Include indicators to measure material use, current material end-of-service-life scenarios, intended future material end-of-service-life scenarios and embodied carbon.
Build the capacity to deliver circular MMC
Step 1 – Create comprehensive guidelines for DfD
Build capacity to deliver circular MMC and increase familiarity with design for adaptability and disassembly among design teams and supply chains.
Step 2 – Engage supply chain with the developed KPIs and DfD guidance
The Housing Pattern Book contains a strong section on circularity and DfD. The guidelines provide technical criteria for design teams to apply through the design process and can frame conversations with suppliers.
Step 3 – Standardise more building elements in the Housing Pattern Book
The Housing Pattern Book already proposes standardisation of bathroom pods and utility cupboards, and it lists additional elements with potential for standardisation: cores, risers, façades and balconies.
Based on RightSizer, one of London’s demonstrator projects, floor, ceiling and partitioning systems could also be developed with suppliers to increase internal flexibility, building adaptability and component disassembly. Progressively address standardisation potential of each building element.
Calculating return on investment (ROI) for design for disassembly and design for adaptability
Applying DfD and DfA principles to building design often leads to higher upfront costs compared to a more conventional linear approach. This is typically due to more expensive less often used materials and techniques being used at the outset. However, as shown by CIRCuIT’s demonstrator projects (see above), DfD and DfA often results in economic and environmental savings over the whole life of a building or material.
To increase awareness of this fact and adoption of DfD and DfA approaches, it’s critical built environment stakeholders have access to the tools they need to clearly assess and demonstrate ROI when using DfD and DfA. As a result, the CIRCuIT project created a robust methodological framework for assessing the ROI for DfD and DfA across three areas: monetary cost, carbon use and material use.
A second methodology was further developed to assess whether a DfD or DfA concept is likely to be scaled up across a city on the back of its ROI assessment.
Both methodologies are covered in more detail in the report D6.4 Part 1 Threefold ROI assessment of building concepts and threefold ROI urban plan – preliminary report. This is available to download at circuit-project.eu/post/latest-circuit-reports-and-publications
Return on investment methodology for DfD and DfA
In the context of applying ROI to DfD and DfA, the investment refers to the money, carbon or materials going into a project over its lifetime.
For this methodology, the ‘net income’ is defined as the potential savings achieved in a second iteration of a building compared to a BAU approach. The ‘net income’ is potential savings compared to BAU of cost, carbon or materials over multiple iterations.
However, the net income can be adjusted to represent any kind of business model that needs to be studied. This can include the resale value of reused materials, the increased rent capture by providing adaptable buildings with higher tenancy, or the simple savings from not having to replace all building elements during refurbishment.
Two types of upfront investment can be identified to calculate the ROI, depending on the business case that needs to be portrayed. This is illustrated in Equations A and B.
In Equation A, the upfront investment is the total investment for the DfA or DfD project, which provides a ROI of the project compared to BAU.
In Equation B, the ROI is calculated on the additional upfront investment required to deliver a DfD or DfA project compared to BAU, and the potential saving this additional investment can bring. Equation B is only applicable on the cases where the upfront cost of a DfD
or DfA project is higher than the BAU.
In the equations:
BAUUC1 denotes built as usual upfront investment in the first iteration
BAUUC2 denotes built as usual upfront investment in the second iteration
DfD/DfAUC1 denotes DfD or DfA project upfront investment in the first iteration
DfD/DfAUC2 denotes DfD or DfA project upfront investment in the second iteration
To illustrate the difference between the two calculations, the costs involved in the adaptable housing demonstrator project in Copenhagen are used in the two equations.
The Equation A calculation illustrates the monetary ROI for the adaptable housing concept in Copenhagen is 38.83% over two life cycles, i.e. the potential money saved over two lifecycles compared to BAU.
The Equation B calculation illustrates the ROI on additional investment to deliver the adaptable housing concept instead of BAU is 230%, i.e. the extra 1320 DKK (approximately €729) a developer spends will potentially result in a 230% ROI over two iterations.
Methodology to assess the scaling potential of DfD and DfA concepts
Once a DfD or DfA concept has been established, the scaling methodology can be used to create a ‘probability’ score. This score determines the likelihood of whether a DfD or DfA concept will be built and then scaled at a city level.
Step 1: Identify an existing source of lost value because of a linear economy in the city
The first step is to analyse current market trends and identify a current loss of value related to a linear construction approach such as premature demolition, vacant land or depreciated building materials. Rate this value loss as significant, less significant or insignificant.
For example, Denmark is prematurely demolishing around 32,000 public housing units. At the same time, 60,000 new dwellings are being built in Copenhagen. Using average data for construction cost and carbon, it’s possible to estimate the potential value loss if circular construction practices are not applied to the new dwellings and they are prematurely demolished.
Step 2: Identify a DfD or DfA solution to the value loss identified in step 1
Next, rate how well you think your DfD or DfA solution responds to the identified value loss in step 1. This could be low, medium or high.
For example, adaptable housing (see above) could prevent Copenhagen from prematurely demolishing buildings in the future.
Step 3: Potential profit score
Use the ROI methodology for DfD and/or DfA (see above) to estimate the potential profit of adopting a DfD or DfA solution. This could be a cost, carbon or materials profit. Apply this to the scale of the problem the solution will solve to get a full grasp of the potential profit from adopting the DfD and/or DfA concept.
For example, in Copenhagen the monetary ROI for using the adaptable housing concept instead of BAU is 38.83% over two iterations. Applying this percentage to the cost of building 60,000 new dwellings (60,000 x 5,437 DKK) means the city of Copenhagen would save nearly 127 million DKK (170 million Euro) over two lifecycles/iterations.
Step 4: Market readiness score
Analyse the degree to which the DfD or DfA solution is market ready. For example, identify the percentage of market ready components, use of standard dimensions, impact on construction line, etc. Rate the DfD or DfA solution not market ready, somewhat market ready or market ready.
Step 5: Implementation scalability score
Analyse the degree to which relationships between stakeholders and requirements (policy, legislation, etc) are in place to implement the DfD or DfA concept instead of BAU.
For example, if there is a need for legislative changes to building codes, implementation might be very complex. If all that is required is an incentive through planning, it might be less complex. Rate your solution high complexity, medium or low complexity.
Step 6: Conclusion
Based on the preceding five steps, make a conclusion about how probable and scalable your DfD or DfA project is.
Making the case for design for disassembly and design for adaptability
A ‘business case’ is understood as making a case for changing something. It is directed at a specific audience who can enact the proposed change. It describes actions to be taken outside of a business as usual (BAU) scenario and the outcomes that are expected. Four of the business cases that were developed by drawing on the carbon and cost analysis of the CIRCuIT design for disassembly and adaptability demonstrator projects are shared below.
Each business case includes five perspectives on making the change that are presented under the headings strategic, financial, feasibility, risk and scalability. Together these commentaries and the demonstrator templates provide evidence on the benefit of investment in the proposed changes for decision makers and local communities.
The full list of all business cases developed from demonstrator results can be found in Appendix A1.2
I. Local authorities can help to create circular supply chains by driving demand for novel DfD construction by adopting its use in public projects
Strategic: If local authorities take a leading role in briefing design teams to specify DfD, they can reduce embodied carbon emissions in line with their own carbon reduction objectives and help to break down barriers to the wider adoption of novel circular construction.
Financial: Compared to BAU, upfront costs were found to be 25% lower for Demonstrator 25 and 1% higher for Demonstrator 26. Lifecycle cost savings of 37% Demonstrator 25 and 61% Demonstrator 26 were achieved once the components were used for a second time.
Feasibility: Adopting novel construction techniques requires strong impetus from those commissioning construction to set a direction of travel. Officers in development and regeneration roles will need to understand the reasons for the policy and act as custodians as the policy is enacted in project briefs and challenged through the course of a project’s development.
Appointed design teams will be asked to design and specify product systems in a way that differs somewhat from their normal practice. Clarity of rationale and awareness of carbon and circularity will be key to resisting pressure to revert to BAU.
Risk: Association with innovative, circular businesses can enhance the reputation of a local authority amongst staff, residents and industry. The opportunity cost of achieving carbon savings or other environmental benefits should be weighed against other options for achieving the same benefits. The starting point is to understand the scale of benefits. In the demonstrator cases, DfD was found to achieve 75% and 85% reductions in embodied carbon emissions once components were used for a second time.
Scalability: The emergence of building futures contracts and a market mechanism for their exchange will lend credence to the long-term residual value of DfD construction, and justify additional upfront investment.
Nevertheless, the ability to scale this business case depends on the availability of DfD products that are ready to apply to major projects. Greater demand for DfD from across the market, driven by progressive purchasing and tighter regulation of whole life carbon, will create more opportunities for businesses to develop such products.
Related demonstrators: Demonstrator 25 – Hamburger Klassenhäuser – Slab construction, Demonstrator 26 – Hamburger Klassenhäuser – Façade comparison.
W. Manufacturers can generate new revenue streams by developing demountable product-as-a-service business models
Strategic: Manufacturers can retain ownership of assets and generate revenue from leasing building products and systems, including partition systems, façade components, warehouse buildings and raised access flooring.
Financial: In the demonstrator projects on which this case is based, upfront costs were found to be higher where systems were designed for future disassembly (by 11–25%). However, lifecycle cost savings were achieved once the components were used for a second time (13–25% saving), and with each additional use cycle this return on investment improved further.
Whilst future returns are inherently uncertain, the Neustadt case showed real savings achieved for the recipient project through the reuse of 200m2 of a partition wall system in collaboration with the original manufacturer. These savings represent a competitive advantage for a manufacturer that is able to disassemble, reassemble and re-warranty their products.
Feasibility: Disassembly and reassembly techniques exist but leasing models remain largely unfamiliar to developers, specifiers and contractors. A shift in mindset is required for these models to become commonplace. Pricing and ownership models need to be considered to suit different component types and market segments.
Risk: There is financial risk in increasing manufacturers’ upfront costs with returns coming over a long period. There is organisational risk for existing manufacturers in developing and integrating new business models where traditional upfront sales models are felt to be effective. However, retaining ownership of materials is a hedge against future resource price rises and price volatility.
Scalability: Leasing models are most applicable to shorter lived building components, temporary buildings and typologies that could be expected to be deployed on different sites before the end of the components’ lifespans. If they become commonplace, it will raise questions over universality/compatibility versus manufacturer-specific technology (e.g. connection types) and subsequently collaboration versus competition amongst manufacturers.
Alignment over technology (e.g. connection types) and robust information retention (e.g. through material passports) will help to ensure that components are disassembled and reused as intended, even if their original manufacturer ceases trading.
Related demonstrators: Demonstrator 27 – Neustadt – Partition walls, Demonstrator 29 – DfD modular façade – Taastrupgård, Demonstrator 32 – DfD warehouse, Demonstrator 36 – Green Street affordable workspace.
E. Public and private developers can create more valuable homes, improve resident satisfaction and reduce lifecycle cost by developing adaptable housing
Strategic: Public and private developers can create more valuable homes, improve resident satisfaction, reduce lifecycle cost and simplify maintenance and upgrades by developing adaptable housing that facilitates multigenerational living and flexibility of living and working.
Financial: In the demonstrator projects on which this case is based, upfront costs were found to be higher where systems were designed for adaptability (by 21–24%). Savings are achieved when dwellings are transformed to suit changing needs, especially where the alternative is demolition and new construction.
In one case, the redevelopment of an adaptable home compared to demolishing and rebuilding after one use cycle resulted in a 28% lifecycle cost saving. Economic benefits for the building owner may also be generated by shortened periods of vacant flats, due to the capability to adapt flats to meet changing demands.
Feasibility: Adaptability can be achieved through simple design changes such as optimising positions of load-bearing elements and building services layouts and accessibility. The demonstrators apply construction methods and technologies that are readily available.
Risk: The resident survey conducted in Helsinki found that there is demand for flat adaptability amongst both owner-occupiers and tenants, as it reduces the likelihood of having to move house, allows changing use of space as family life and work life change, and makes it possible to rent or sell a part of the flat to yield income.
There is a willingness to pay a premium for adaptability, generally 2–10% on top of the purchase price, if its potential benefits are clearly communicated. For building owners, investment in adaptability reduces the risk of buildings being demolished before the end of their technical lifespan.
Scalability: In owner-occupied housing, the investor and the beneficiaries are different. The potential savings must be communicated and recognised as additional value at the point of sale, otherwise the split incentives will reduce motivation to invest in adaptability. For public developers and housing associations that retain ownership of buildings, adopting lifecycle costing is essential to assess the merit of designing for adaptability.
Related demonstrators: Demonstrator 28 – Copenhagen adaptable housing, Demonstrator 33 – Helsinki adaptable flats, Demonstrator 35 – RightSizer
F. Public and private landowners and asset owners can achieve increased rental income by facilitating ‘meanwhile use’ of underused land and assets
Strategic: The term ‘meanwhile use’ represents a range of strategies that can be put into place to make under-utilised spaces and places become productive, both in an economic and social sense.
Landowners can achieve increased rental income by identifying opportunities for ‘meanwhile use’ and maximising use of land and assets prior to longer term redevelopment.
Financial: Land and assets earmarked for redevelopment are often protected with hoarding and security services in the period before construction starts. These periods of under-utilisation of assets are often significantly longer than is first anticipated, potentially leading to years of outgoings.
Meanwhile use’ achieves rental income and avoids the need to pay for securing disused sites, but it requires investment in a temporary building (by the landowner or others) that may need to be deployed multiple times to achieve a return. The demonstrator on which this case is based was a disused brownfield site. Upfront construction costs of a relocatable building to suit a 10-year lease period on the site were found to be 6% higher than an equivalent building not designed to be relocatable. However, lifecycle costs for three 10-year uses of the building were 23% lower.
Feasibility: Information about a site’s previous use allows assessment of the capacity of any existing foundations. In the demonstrator case, the ‘meanwhile building’ was designed to be lighter than the previous building so that no new foundations were required. The demonstrator used standard construction materials and techniques, with some modifications to improve design life and demountability.
Construction supply chains are not fully prepared to scale these techniques to maximise their potential impact, but the supply capacity and skills required are within reach. Deconstruction and relocation expertise exists, but it will also need to be scaled to meet the needs of a larger market in relocatable buildings.
Risk: Maximising return on investment will require ‘meanwhile buildings’ to be deployed multiple times. Under current regulations, a building will be defined as new at the point that it is relocated to another site. It will require full planning permission and will need to meet the relevant building regulations of the day. This may add complexity and cost to future relocation.
Scalability: All buildings become non-compliant over time, but existing buildings that remain on the same site do not need to be recertified every 10 years. This raises the question – Should relocatable buildings become a new special category and regulations relaxed to simplify their widespread adoption?
Taking London as an example, there are 466 disused plots of land of a size that would be suitable for ‘meanwhile use’ similar to that adopted by Demonstrator 34. The total area of this land is nearly 500,000m2. In the UK as a whole, there are 36,000 disused brownfield sites. This represents a significant opportunity to roll out ‘meanwhile use’ prior to redevelopment.
Related demonstrators: Demonstrator 34 – Albion Street / The Hithe
For further information about the outputs featured in this report and the work behind them, please read the following reports, which were published by members of CIRCuIT partner organisations during the lifetime of the project.
D6.2 Circular building concepts for concrete, hybrid concrete-wood, and volume construction
D6.3 Set up of demonstrators and scenarios for four partner cities
D6.4 Part 1 Threefold ROI assessment of building concepts and threefold ROI of urban plan – preliminary report
D6.5 Four city case roadmaps for implementation
All these reports can be downloaded at circuit-project.eu/post/latest-circuit-reports-and-publications
The following individuals authored the deliverables that form the basis of this chapter.
Ann-Britt Vejlgaar, GXN
Anthony Maubach-Howard, Hamburg University of Technology
Colin Rose, ReLondon
Duncan McNaughton, Grimshaw Architects
Frank Beister, Otto Wulff
Henna Teerihalme, Helsinki Region Environmental Services Authority
Janus zum Brock, Hamburg University of Technology
Jukka Lahdensivu, Ramboll
Jyrki Tarpio, Tampere University
Karolina Bäckman, GXN
Kimmo Nekkula, The City of Vantaa
Lasse Lind, GXN
Maike Hora, e-hoch-3
Marco Abis, Hamburg University of Technology
Masha Doostdar, e-hoch-3
Nichlas Moos Heunicke, GXN
Peter Swallow, Grimshaw Architects
Philipp Wendt, The City of Hamburg
Rachel Singer, ReLondon
Salma Zavari, Vandkunsten Architects
Satu Huuhka, Tampere University
Tessa Devreese, ReLondon
Tiina Haaspuro, Helsinki Region Environmental Services Authority
Uta Mense, The City of Hamburg
Ville Tarvainen, Ramboll
Asger Nørregård Rasmussen, Maker
Karolina Backman, GXN