Government incentives can encourage the re-use marketplace and widespread adoption of secondary materials.

Secondary materials such as scrap or residuals from construction processes are currently massive sources of waste and have great potential for integration into building structures. For secondary materials to compete strongly in the construction materials marketplace, technical, operational, social, cultural, regulatory and economic limitations need to be overcome (Knoth, Fufa and Seilskjær 2022). Policymaking is key in helping to overcome limitations such as the lack of a regulatory framework. Government incentives can encourage both the re-use marketplace as well as the widespread adoption of secondary materials and selective deconstruction practices.

Funding Is Needed to Address Technical Challenges

From a design perspective, the weight and dimension of an element or material can greatly influence its re-usability. Lighter and smaller materials and components, designed with flexible joints, will be more feasible to reuse. Funding mechanisms are needed to advance research and development to overcome technical limitations of re-use and recovery, such as material degradation, seismic and fire-proof specifications, and design for disassembly.

Research can also help tailor frameworks for re-use to different contexts. As was illustrated for Lima and Montréal (see Box 3.1), the carbon savings from end-of-use strategies can differ across regions depending on the technical specificities. In regions where reinforced concrete is commonly used, the re-use of structural elements is less viable. For earthquake-prone regions, the design of re-usable structural elements will need to address the seismic resistance of materials. In contrast, in regions that use lighter materials, such as wood, the potential for re-usability is higher. However, most secondary lightweight wood is not reused or recycled today but is used mostly for energy recovery (see chapter 4).

Education Is Required to Increase Technical Knowledge and Social Acceptance

To increase technical knowledge exchange on the use of secondary materials, governments can support training, education and research on the practices and skills needed to conduct selective deconstruction (McClure and Bartuska 2007; Deplazes 2012; Rondinel-Oviedo and Schreier-Barreto 2019; Cruz Rios and Grau 2020; Hossain et al. 2020). From a socio-cultural perspective, specific messaging also needs to be developed to shift the mindset that secondary materials are of lesser value. Instead, it is important to convey the notion that these materials are desirable and to support their acceptance in the marketplace.

Policies Can Support Standards for Secondary Materials and Incentivise Markets

Markets are needed for re-usable products, with specialised contractors and re-use centres leading to new job opportunities

The development of assessment standards and certifications for secondary materials is key in assuring the safety and efficacy of re-use materials. This, in turn, can help promote selective deconstruction. Policies are needed to develop and regulate the government approval process for materials before they enter the marketplace. For instance, secondary materials must meet recognised material standards and certification regarding their composition and properties, and must also comply with building codes. Secondary materials must be assessed to ensure that they meet the same standards as virgin materials in order for legal limitations and social acceptance to be overcome.
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Economic drivers for re-use can be as effective as legislation (King 2021). Financial incentives can support the creation of a re-use marketplace – new enterprises and specialised deconstruction contractors that allow for the careful dismantling of a building and for the storing, preparation and maintenance of secondary materials for resale. This includes establishing re-use centres that concentrate end-of-use materials in a “one-stop shop” (Forrest 2021), where elements with higher value can be resold before going to sorting facilities. By enabling circular economies in the building sector, new job opportunities can be provided.