DESIGN FOR DISSASSEMBLY / DEMOLITION / DECONSTRUCTION

1.1. DESCRIPTION Design for Disassembly or Design for Deconstruction is a design practice that involves designing the building, already at an early stage, looking at the end of life, i.e. adopting solutions and drawing up an accurate plan for the disassembly of the structure into its various components. Following this technique it is possible to reuse entire components in other buildings, if the deconstruction is non-destructive, or to recover materials through selective dismantling, if the entire component cannot be removed without damaging it or cannot be used further. 1.2. RELEVANCE FOR CIRCULAR BUILDINGS This practice is particularly relevant for the circularity of buildings: by designing the building looking already at its end-of-life phase, all 9 principles of circularity apply. First of all, there is the reduction in the production of construction waste, as the assembly is designed to be quick and easy on site; moreover, this design philosophy ensures the reuse and/or recycling of disparate products and components. In addition, it is a technique that is not only valid for new constructions, but also for intervening locally, on existing buildings, allowing the possible reversibility of the intervention. 1.3. INNOVATION ASPECTS This way of designing the building is totally innovative and different from any traditional approach. For this reason, it is necessary for new designers to be trained directly in this philosophy, while the more experienced ones keep up to date and are willing to get involved: in particular, it is necessary to be familiar with digital design tools, such as BIM, which can guarantee disassembly. At the same time, special care is required of supplier companies, especially when it comes to construction products supplied in prefabricated packages, to ensure their disassembly, which may necessitate changes in production lines. Another new aspect arising from Design for Disassembly is the need to introduce into the supply chain a figure or company with expertise in disassembly practices and the logistics of the resulting materials, to be involved from the earliest planning stages.

2.1. PRACTICAL APPLICATIONS - Use of prefabricated elements - Preference for mechanical joints (bolts, joints...) over chemical joints (gluing, welding) - Ensure accessibility of connections - Maintain as much independence as possible between the various components to facilitate disassembly - Use a basic open building configuration - Limit the use of finishes and treatments that may compromise the reuse of components and/or recycling of materials - Drawing up a disassembly plan, indicating the steps (disassembly sequence planning), machinery, handling space and destination of each component or material - Design and manage the building by layers (site, envelope, structure, services, interior, furniture)

3.1. BENEFITS - Limitation in the production of construction and demolition waste by 65-80% - Possibility of giving a second life to entire building components, in the case of non-destructive dismantling, or, in the worst case, destructive dismantling, to individual materials - Limitation in the use of virgin raw materials - Extension of the service life of building parts - Reduction or elimination of landfill costs of products - Ease of separation of materials in case transport to landfill is unavoidable 3.2. COMPLEXITIES - In the case of chemical joints, disassembly is only possible through the use of solvents or mechanical operations that may compromise the possibility of recycling the material - Much more complex and time-consuming planning that must go all the way to the end-of-life phase, even providing indications after that time - Perfect disassembly and component recovery plans only guaranteed through the use of digital technologies such as BIM and digitisation of supply chains - Need for numerous means and spaces for disassembly and to define precise sequences, also with time indications, in order to avoid interference in the different processes, which are often difficult to respect - Training of designers needed to instruct them in this design approach - Disassembly of certain structures, especially steel, more expensive than traditional demolition operations