Decarbonizing buildings will not be possible without taking a whole lifecycle approach to their construction and ensuring the rapid decarbonisation of building materials. Building material choices made in infrastructure policy, urban planning and building design requirements have profound impacts on GHG emissions. The precise set of policies to optimise building material decarbonisation must be informed by the assessment of the specific context. Regulation is required across all phases of the building life cycle, from extraction of materials through end-of-use of buildings, to ensure the development of a viable, circular supply chain of sustainable material options. Efforts to decarbonise the material supply chain are synergistic with measures undertaken to ensure fair labour and gender equity. This requires radical collaboration and simultaneously supporting material producers/manufacturers and consumers such as architects, developers, communities and building occupants.
Policy makers will need to engage all actors across the entire value chain and concurrently enable the implementation of the three main decarbonisation principles discussed in this report:
AVOID material overuse and new material extraction by building (with) less, actively seeking ways of reusing and recycling buildings and materials.
SHIFT to sustainably produced low carbon renewable building materials such as earth and biobased materials whenever possible.
IMPROVE methods to decarbonise carbon-intensive conventional materials such as concrete, steel and aluminium, and only use them when necessary.
Across regions, implementation methods will vary as patterns in material flow scenarios differ. In highly developed regions, incentives need to focus on the renovation of existing and ageing building stock, whereas in developing regions with rapid rural to urban migration, there is an opportunity to radically re-invent new construction techniques and leapfrog over prior modern practices by dramatically improving conventional material production, reconnecting with existing, local climate-specific building knowledge and vernacular traditions, and shifting to sustainably sourced biomaterials wherever possible.
Annex 3 provides short summaries on how countries that have very different built environment contexts – Canada, Finland, Ghana, Guatemala, India, Peru and Senegal – can pursue decarbonisation using the “Avoid-Shift-Improve” strategies.
To drive market transformation and stakeholder action, governments should take action to:
Set the vision, lead by example and improve multi-level governance
Make carbon visible through improved data access and quality
Adapt norms and standards to allow for the use of circular, alternative or lower-carbon, bio-based building materials and construction practices
Accelerate the industry transition
Ensure a just transition
Strengthen international action and collaboration for collective impacts