Copenhagen
Adaptable housing

Demonstrated Innovation

This demonstrator derives from BAU apartment housing in Denmark which generally consist of prefabricated concrete construction with loadbearing external and internal walls. The structural system of the BAU is highly difficult to adapt and re-use due to due to load bearing parting walls and cast concrete between building elements. As a response, an alternative structural system has been developed based on frame construction which can be delivered with different structural compositions:

1. Hybrid – structural system with load bearing concrete core and relating structural bay in precast concrete for external walls and floor. Remaining structural frame with concrete columns, steel beams, timber wall construction and CLT floor slabs. All connections are either mechanical or dissolvable allowing for future dismantling without loss of material value.

2. Timber – structural system with load bearing concrete core. Remaining structural frame with concrete columns, steel beams, timber wall construction and CLT floor slabs. All connections are either mechanical or dissolvable allowing for future dismantling without loss of material value

Compared to the BAU the alternative structural systems allow for reconfigurable internal walls (due to them not being load bearing), vertical and horizontal extensions of apartments (due to structural independencies), accessibility to building systems (due to building layers being separable) and a high DfD potential.

​

Activities Done:

• Market analysis of current BAU cases from the Copenhagen housing development market.

• Socio-economic analysis for scenario development for definition of design scope.

• Development of proposals for alternative structural systems with a focus on DfD and adaptability. Proposed systems have been studied in detail for two key structural focus areas essential to enabling increased adaptability (façade-slab connection and internal wall-slab connection)

• BIM modelling for LCA and DfD analysis

• Initial LCC study based on cost data from Danish cost database.

• 1:1 Mock-Up model of DfD construction detail for floor slab

• Exhibition models and report for communication around demonstrator findings

​

Demonstrated Impacts:

It has been shown that the demonstrated alternatives have substantially higher reuse potential compared to the BAU case (85%). This is especially due to how assemblies between structural elements are designed, in the BAU case structural elements are cast together making non-destructive disassembly practically impossible, whereas it has been demonstrated how bolted assemblies increases the reuse potential to 85%.

The results indicated that the embodied carbon of BAU and the two studied alternative systems are almost the same in the first erection of the building. If the building were to be redeveloped (for example due to demographic changes) the embodied carbon saving are 37% after the first redevelopment, and 50% after two.

The cost of the alternative systems and disassembly instead of demolition is 25-28% more expensive than BAU. However, again if the building were to be redeveloped the DfD system provides 27% savings after the first development and 45% after two.

This points towards that designing for increased DfD/adaptability might require a high upfront investment, but extending the lifecycle of the building elements creates a substantial saving already after one redevelopment scenario.