Design for DisassemblyFrom Construction Waste to Material Resource: How Design for Disassembly helps lead to a Circular Future

Think about the last time you saw a building being demolished. It’s a chaotic scene, with plumes of dust and the constant banging noise of pneumatic hammers. Think about the mountains of rubble and materials that had previously formed the building, now forming in piles. Think about the waste of resources, the waste of energy and the waste of money as this building, once an asset, is now a waste stream to be disposed of.

Now think, what if it didn’t have to be that way? What if that building had been designed to be carefully disassembled, with its materials finding new life elsewhere? That’s the question we asked ourselves when designing the Red Bank Hotel extension in Carrick-on-Shannon.

We’re all familiar with the idea of constructing a building, but what if we flipped that on its head? What if, from the very beginning, we designed buildings with their future disassembly in mind? This is the core concept of Design for Disassembly (DfD), a radical shift in architectural thinking that’s driving some of our work at ACT.

It might sound counterintuitive – planning a building’s “un-building” before it’s even complete – but DfD is essential for a truly sustainable construction industry. Our project, The Red Bank Hotel, a 12-bedroom boutique extension to an existing restaurant which has recently received planning permission, perfectly illustrates this principle. This addition enhances the visitor experience in Ireland’s Hidden Heartlands and the Wild Atlantic Way, but it also demonstrates a commitment to circularity. The extension harmonises with the original Victorian redbrick building, showcasing that heritage and modern design can beautifully coexist.

While our design approach was informed from the outside in, responding to the orientation, scale and proportions of the building’s context, it was also developed from inside out. Using a 1200mm hollow core slab as the basic element, the proposed design builds from there with the systems from structural steel frame to stone panel facade all sized to standard dimensions for potential future reuse.

 Projects like the Red Bank Hotel extension and the Scotch House project in Ballina, exemplify our commitment to Design for Disassembly in practice, extending beyond theoretical concepts. In the Scotch House design, we prioritised retaining existing structures, utilising lightweight panelised straw blocks and selecting reusable clay tiles, all contributing to a circular building assembly. Currently, as we are developing the tender drawings for this project, we are also developing the plan for its future potential disassembly.  

What does this look like? Unsurprisingly it’s the reverse of a typical construction plan of works. Beginning with the building stuff (loose furniture, household items, etc.) and finishing with the structure, we plan how the various layers of the building can be pealed away. This concept of Shearing Layers was described by Steward Brand in his book How Buildings Learn where he expands on the thinking of Frank Duffy. It explains how the various layers of a building have differing life-cycles and rates of change.

Thinking of a building as these separate but connected layers and differing rates for change helps us to consider their interfaces, how they are joined how they will be serviced and how they will be replaced. Within each layer we have the individual building components. For example, the Space Plan will include partition walls, joinery, finishes and so on. Elements like a partition wall will be comprised of sub components, plaster board, insulation, studs, and screws. Within the disassembly plan we define the location of the components, the method for disassembly, much like a specification of assembly, and the method for material storage for later reuse or recovery.  We use schedules, drawings, BIM models, photographs of elements and method descriptions, all of which are familiar to Construction Professionals but now used to disassemble rather than construct.

Ireland faces a significant challenge with construction and demolition waste, which is the nation’s largest waste stream. DfD directly addresses this issue by designing buildings for easy disassembly, ensuring that materials can be efficiently reused, recycled, or reclaimed.

Up to 48% of Irelands waste comes from the construction and demolition industry which is a staggering proportion. While direct reuse of existing structures is by far the best way to reduce environmental impact, we can’t always control if this will happen. This is why DfD is a crucial tool for sustainable design. By designing in this way and creating a deconstruction plan for our buildings, we substantially increase the value of the buildings fabric making it easier to service and maintain and making it much more likely that the buildings components will be reused elsewhere when it comes to end of life.

While DfD is a new approach, it’s also practical and can be described through principles and strategies that can be integrated in the design process. DfD includes:

• Using Recyclable & Renewable Materials
• Avoiding Composite & Hybrid Materials
• Material Standardisation
• Using Mechanical Fasteners
• Using Modular Joints & Plug-and-Play Systems
• Prefabrication of Structural Elements
• Standardisation of Modular Components
• Separation of Systems (Shearing Layers Concept)
• Providing Accessible & Visible Service Systems
• Material & Component Labelling
• Creating Digital Material Passports
• The Development of a Disassembly Plan

Some of these principles such as the use of prefabricated elements or the use of mechanical fasteners are familiar to the industry and can be easily integrated into a project through Design Team coordination and construction specification. Other principles like the Development of a disassembly plan are new and require more detailed coordination with Design Team members, contractors and sub-contractors. We’ve found that while we’ve been able to include the majority of the DfD principles in the design for both Scotch House and Redbank to a greater or lesser extent, the creation of Digital Material Passports for components has been a bridge too far for the moment. This being said, each project is a steppingstone, helping us get to the goal of designing and constructing buildings that will integrate all principles helping us to support a circular future for the built environment.

All of this will help to minimise our negative impact on the planet while retaining the value of the materials we build with. It’s about challenging the industry to embrace a circular model where resources are valued and waste is minimised. It’s about proving that innovative design and environmental responsibility are not mutually exclusive.

This article was originally written for the Irish Green Building Council, read it here.