Guest Article: Building Materials – A Hidden Heavyweight for Climate Action | SDG Knowledge Center

By Anna Zinecker, PEEB (Bonn/GIZ), and Jérémy Bourgault, PEEB (Paris/AFD)

An era of massive construction is currently underway, with a new district the size of Paris being built every week. The overall surface area of ​​buildings is expected to double by 2060, which will have a massive impact on the climate. The production of building materials and construction activities are already responsible for 10% of global energy-related greenhouse gas emissions.

To avoid locking carbon into the system for decades, infrastructure investments must be moved urgently.

Building materials have a high carbon footprint and represent a concrete challenge for the climate. The “embodied carbon” in buildings comes mainly from the energy-intensive production of cement, steel, aluminum, glass and insulation materials. The production of materials like cement also involves chemical processes, releasing additional greenhouse gases (GHGs), and leads to the depletion of natural resources like sand and the erosion of ecosystems.

Strategies to fight embodied carbon – and out-of-the-box solutions

We need to rethink the way we build our buildings to reduce embodied carbon. Strategies to reduce embodied carbon already exist – from building smarter to decarbonizing building materials. To shed light on these solutions, the Program for Energy Efficiency in Buildings (PEEB) recently released a discussion paper outlining key facts about embodied carbon, along with practical strategies to reduce it. This video from PEEB explains the main facts.

PEEB sees three approaches: avoiding embodied carbon by designing for less material usage; switching to alternative building materials; and improve conventional materials by making them less carbonaceous.

On the first strategy, avoiding embodied carbon by reducing the use of materials, resource efficiency is the basis. We can build less, build with fewer materials, and build more sustainable and resilient buildings. = Circular approaches to construction can even turn buildings into banks of valuable materials that can be reused through “urban mining”.

The second and third approaches require a dual strategy. We need fast action to reduce emissions from the production of conventional building materials, mainly concrete and steel, but also aluminium, plastic and glass. At the same time, we need to increase the market share of alternative low-carbon materials such as biomaterials.

Low-carbon building materials and building solutions already exist and are ready to scale. Companies and start-ups around the world have developed alternative materials that have become cutting-edge products for today’s real estate markets. On the industrial side, large companies like cement and steel producers are looking to decarbonize their production.

Construction takes center stage in climate talks

Despite its massive role in global emissions, the embodied carbon of buildings remains a “blind spot” in discussions about how to reduce GHG emissions. At the United Nations Climate Change Conference in Glasgow (UNFCCC COP 26), stakeholders mobilized to put the built environment in the spotlight. We need a lifelong carbon approach when it comes to addressing emissions from the complex value chains that make up this sector.

As long as solutions exist, dedicated policies and financial support are needed to foster a business environment capable of addressing embodied carbon.

On March 24, 2022, the best solutions for advancing policy and financing were discussed in a building materials webinar co-hosted by PEEB, GlobalABC, ABC21 and the ACT initiative. Experts from India, Morocco, France and the United States discussed the challenges and potential solutions to decarbonizing building materials.

“India and Africa will add several times the size of Paris to the world in the years to come,” said architect Chitra Vishwanath of Biome Solutions in India, pointing to the massive growth in construction in developing countries. To avoid locking carbon into the system for decades, infrastructure investments must be moved urgently. Decisions that are made now “will shape cement and steel production in 2050,” said Marlene Dresch of the ACT Initiative, which helps companies develop concrete decarbonization strategies. She stressed the urgency of a clear transition plan for the decarbonization of building materials aligned with the goals of the Paris Agreement.

Around the world, there is an urgent need to make embodied carbon visible through better data and awareness. Building regulations still primarily target operational carbon – the energy used during the operation of a building. Performance-based building codes that include materials are just getting started. Funding is needed to deploy technologies to reduce the carbon content of conventional building materials, and webinar participants highlighted the role of global carbon markets in accelerating this.

Anupam Badola of Dalmia Cement in India highlighted the high share of public sector construction demand, where green procurement protocols and policies can create market demand for improved cement and steel. Asmae Khaldoun from Al Akhawayn University in Morocco highlighted the potential of bio-based and geo-based building materials as modern building materials, and their strong potential for creating local jobs.

What’s next in 2022?

Reducing energy use and GHG emissions caused by the way we build is essential, and embodied carbon in buildings must be high on the agenda of policymakers, businesses and practitioners everywhere. In 2022, the Global Alliance for Buildings and Construction will use advocacy and research to raise building materials and embodied carbon up the global agenda. Several Alliance members are working with development banks and investors to increase investment in buildings that address lifelong carbon.

This guest post is written by Anna Zinecker, Program for Energy Efficiency in Buildings (PEEB), Bonn/GIZ, and Jérémy Bourgault, Program for Energy Efficiency in Buildings (PEEB), Paris/AFD.