Design for Disassembly (DfD) is a design process that allows the recovery of parts and materials when a building is being renovated. This article aims to highlight that over 110 million square feet of commercial spaces are slated for e-retrofitting. In today’s context of sustainability, designers can minimise environmental impacts through the 4Rs: reuse, repair, remanufacture, and recycle. Simultaneously, they can maximise economic value.
At the end of the life cycle, several strategies can be employed to recover a building’s façade system or its individual parts. During the design stage, the deconstruction strategy for the façade system should be approached carefully, using a step-by-step methodology, design schemes, and what-if analyses. Standard operating procedures or guides can help stakeholders define the expected service life of a façade.
The perceived service life of a façade or its parts can be affected either by being perceived as outdated due to changes in technology or aesthetics of new surrounding buildings or by actual deterioration in physical performance leading to a decline in intended functionality. This inevitability underscores the need for a DfD (Design for Deconstruction) approach, which provides value to both the owner and the user.
What does the DfD approach entail?
- Recycled materials: Using recycled materials wherever possible.
- Avoiding secondary finishes: Minimising the need for additional finishes on materials.
- Reducing the number of parts: Simplifying the design to minimise the number of components.
- Investing in modular systems: Opting for modular systems that allow for easy replacement of parts.
- Mechanical assembly vs. chemical bonding: Prioritising mechanical assembly over chemical bonding.
- System designs with changeable parts: Designing systems where individual parts can be easily replaced.
- Standard practices and identification numbers: Ensuring compatibility with industry standards and providing clear identification for all parts.
The sustainable approach should also avoid toxic and hazardous materials, using lightweight designs and installation mechanisms that can be easily deconstructed. From an aesthetics standpoint, it is also imperative to ask questions about what will happen to a system once the perceived service life has reached its end, how adaptable is the system to changing climatic conditions, and will the users appreciate it.
The practice will allow existing materials to one day serve as the primary source of materials for replacement during construction, effectively harvesting existing stock rather than depleting natural resources. This approach is encouraged by the diminishing availability of natural resources.
Present challenges
Although DfD (Design for Disassembly) has gained recognition in recent years, a significant gap still exists between theory and practice. Several barriers contribute to this disparity, including negative perceptions about reusing materials, lack of information about specific parts, suppliers’ reluctance to provide guarantees, perceived performance risks, and a shortage of necessary skill sets. The industry must seriously address these inefficiencies, and stakeholders should collaborate to evaluate and establish guidelines or policies that incentivise sustainable developments. The EU Regulation 305/2011 emphasises the importance of designing, constructing, and demolishing buildings in a way that ensures the sustainable use of natural resources. It further mandates that materials and parts must be reused or recycled after demolition.
Is DfD better than traditional techniques?
The deconstruction process differs significantly from traditional demolition strategies. The cardinal idea behind DfD revolves around the basic principle that structural systems (such as aluminium frames) have the longest lifespan and can be restructured for reuse. The primary goal is to reduce pollution impact, minimise resource consumption, and enhance economic efficiency during the removal of façades, as well as the recovery of systems or parts for reuse and recycling. Keeping this in mind, the façade system and material selection should be designed for easy disassembly, replacement, reconfiguration, and reuse.
Additionally, specific interventions (such as maintenance and refurbishment) are necessary to reduce the deterioration of the façade and ensure that the system meets expected performance criteria. For example, repairing or replacing flashing and seals in windows and other parts is crucial. Similarly, predicting future façade styles or technological advancements (such as improved glass performance) is challenging. Therefore, when the old must make way for the new, the strategy of disassembly and replacement should take precedence over demolition.
In conclusion, timely upgrades to the building façade are essential for owners to remain competitive and for the building to remain attractive to investors and tenants. The aesthetic and technical sustainability of the façade system requires designs that allow for easy configuration and restructuring to meet ever-changing demands, not just those dictated by the lifecycle.
