Circularity in the Built Environment 2024

Retrofit-specific design for circularity Retrofit-specific technologies for circularityBOX 6 BOX 7Decision-making in retrofit design can be supported by conducting whole life-cycle assessments. These assessments calculate carbon emissions resulting from the retrofit, including upfront embodied emissions and operational emissions across the entire asset life cycle. This holistic view enables more informed and sustainable retrofit design choices. Three-dimensional (3D) scanning technology can convert existing buildings into digital twins using point clouds, enabling the integration and use of Building Information Technology systems. This provides greater clarity into the existing building design and aids designers in planning and renovators in conducting effective circular retrofits.Measuring and tracking the impact of materials is crucial to scaling circular practices. While initiatives like the Science Based Targets initiative (SBTi) provide frameworks to effectively measure Scope 1 and 2 emissions, there remains an opportunity to enhance monitoring of the environmental effects of construction, including virgin material consumption, water and land use, pollution and effects on biodiversity. By adopting digital materials passports, designers, manufacturers and upgraders could establish transparency in materials impact. These passports create a comprehensive record of the materials and parts used in a building and can increase the residual value of materials, creating opportunities for logistics and waste handlers. The extent to which building materials passports have been adopted around the world and the approaches being taken are not well documented. The Global Alliance for Buildings and Construction (GlobalABC) has introduced a Digital Construction Material Passport, an open-source tool designed for global use.38 At the same time, national frameworks are emerging. In Germany, the German Sustainable Building Council (DGNB) has launched a digital building resource passport aimed at enhancing transparency. This passport includes information on the use of circular materials, life-cycle greenhouse gas emissions, non-renewable energy demand and the feasibility of deconstruction.39 Efficient logistics networks and take-back programmes that ensure that quality salvaged materials can be reconditioned and reused are the backbone of a circular value chain. Manufacturers can set up take-back mechanisms and collaborate with other materials and parts manufacturers to recirculate materials from deconstruction and extract valuable materials. For example, aluminium and glass manufacturers can partner to recirculate materials salvaged from building facades. Distributors and logistics handlers, together with manufacturers and waste handlers, can establish a network of disassembly, storage and recycling hubs, ideally located near densely populated areas or construction sites. For example, the Dutch government is exploring the use of urban mining hubs to bolster the circular built environment by 2050.40 Digital platforms for waste materials and reusable components can streamline the identification, tracking and management of these materials, while also serving as a marketplace for their exchange and sale. Transporting salvaged materials presents opportunities for non-construction companies to generate new revenue streams. For instance, Swiss Post has successfully entered this market by providing construction-site logistics services, demonstrating the feasibility for new players to penetrate and thrive in this sector.41 These handlers could even explore the potential to sell salvaged materials back to manufacturers for the purpose of recycling.3.2 Technology, equipment and tools 3.3 Reuse and recycling infrastructure Circularity in the Built Environment: Unlocking Opportunities in Retrofits 21