Rapid urbanisation worldwide means every five days the world adds buildings equivalent to the size of Paris, with the built environment sector already responsible for 37% of energy- and process-related CO2 emissions and over 34% of energy demand globally.
A report published by the United Nations Environment Programme (UNEP) and the Yale Center for Ecosystems + Architecture (Yale CEA), under the GlobalABC, titled Building Materials and the Climate: Constructing a New Future, offers solutions to decarbonize the buildings and construction sector and reduce the waste it generates.
CIB is a member of the Global Alliance for Building and Construction (read news article here).
Three-pronged solution
The report, Building Materials and the Climate: Constructing a New Future, offers policy makers, as well as manufacturers, architects, developers, engineers, builders and recyclers, a three-pronged solution to reduce “embodied carbon” emissions and the negative impacts on natural ecosystems from the production and deployment of building materials (e.g., cement, steel, aluminium, timber, biomass):
- Avoid waste through a circular approach: building less by repurposing existing buildings is the most valuable option, generating 50-75 per cent fewer emissions than new construction; initial planning using computer-aided design optimisation to promote construction with less materials and with materials that have a lower carbon footprint and facilitate reuse or recycle.
- Shift to ethically and sustainably sourced renewable bio-based building materials, including timber, bamboo, and biomass. The shift towards properly managed bio-based materials could lead to compounded emission savings of up to 40 per cent in the sector by 2050 in many regions. However, more policy and financial support is needed to ensure the widespread adoption of renewable bio-based building materials.
- Improve decarbonisation of conventional materials that cannot be replaced. This mainly concerns the processing of concrete, steel, and aluminium, three sectors responsible for 23 per cent of overall global emissions today, as well as glass and bricks. Priorities should be placed on electrifying production with renewable energy sources, increasing the use of reused and recycled materials and scaling innovative technologies. Transformation of regional markets and building cultures is critical, through building codes, certification, labelling and the education of architects, engineers, and builders on circular practices.
The three-pronged solution of Avoid-Shift-Improve needs to be adopted throughout the building process to ensure emissions are slashed, while human health and biodiverse ecosystems are protected. The solution also requires being sensitive to local cultures and climates, including the common perception of concrete and steel as modern materials of choice.
