Copenhagen
DfD modular façade

Description

Modular prefab solutions are becoming more widely used in the Danish construction industry. Modular prefab construction is often the competitive choice due to production and cost efficiency. Though modularity is regarded as a key element in circular design and construction, DfD is often disregarded for commonly used prefabricated facades.

 

This demonstration investigates how the production of a prefabricated faced module can be optimised for deconstruction (DfD), within the existing production line. The scope of the assessment is a modular timber cassette façade. The climate screen is not included in this investigation, but only examines the façade module structure.

 

The demonstrator was developed as part of the redevelopment of residential housing in Taastrupgård - a Copenhagen suburb. It includes the renovation of 28 residential blocks together with 584 units. Unfortunately, the demonstrated solution was not chosen to be included in the project. However, a physical mock-up of the façade was built.

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Demonstrated Innovation

It has been shown that the production line of the investigated prefabricated façade module can be adjusted relatively easy to increase DfD potential.

 

In the BAU case the different elements of the façade cassette are nailed and stapled together resulting in a DfD potential below 16% by volume.

 

The primary intervention of the demonstrator has been to ensure connections for disassembly between the different building materials. The proposal studied the use of screws and tape instead, and focus on the assembly sequence for deconstruction. The outcome was a disassembly potential of 89% by volume.

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Activities Done

• Façade module construction analysis for DfD optimisation.

• Replacement of DfD obstructing connections

• BIM modelling for LCA and DfD analysis

• Mock-up of demonstration constructed

• Cost impact analysis from DfD intervention

 

Demonstrated Impact

The proposed intervention has shown a potential increase in design for disassembly from 16% (BAU) to 89% (intervention). The façade module’s BAU case was designed to allow some DfD. Hence minor tweaks e.g., replacing stapled and nailed joints with screws in the construction process was the primary change. This minor intervention still resulted in a significant DfD potential increase indicating that connections / joint type is key for DfD optimisation.

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