What are Low Carbon Materials?  

Low carbon materials, or sustainable building materials, are construction-specific products that are carefully designed to reduce the amount of carbon emitted over their lifecycle. The lifecycle of construction materials is defined as the stage when raw materials are extracted, manufactured, transported, installed, and then finally disposed of. This means that before materials are transported and used, the carbon emitted from materials can be reduced in the production phase. This can be done by recycling waste products from demolished buildings that otherwise would have been at the end of their life, or sourcing materials capable of capturing and storing CO₂. 

Sustainable building materials have environmental considerations that traditional materials typically do not have. The production and use of these materials equate to less natural resource depletion, less energy consumption, less pollution, and less toxins for both the planet and its inhabitants. Some popular examples of low carbon products include sustainable timber, lower-carbon concrete and cement, as well as repurposed waste material. 

As a natural carbon sink, sustainably sourced timber continues to sequester, or capture, carbon throughout the entire lifespan of a building. One way to ensure this is by using cross-laminated timber, which is a lightweight, yet strong, engineered wood panel that generates minimal waste during installation. Cross-laminated timber is made from sections of dried boards that are stacked in alternating directions, bonded with adhesive, and pressed to form a solid panel. Each cubic meter of this timber typically stores around 0.9 tons of CO₂. 

Traditional cement production generated 1.5 billion metric tons of CO₂ in 2024, that’s about 8% of the world’s total carbon emissions! Of these emissions, the process of creating clinker – the primary component of cement – makes up 90% of overall cement emissions. Alternating the formula to cut out clinker can significantly reduce the carbon footprint of cement, but no commercialized solutions exist that can completely replace clinker at scale. Some replacements that can be used on a small scale include ground granulated blast furnace slag, which is a byproduct of steel production, fly ash, which is a byproduct of coal-powered furnaces, and recycled concrete aggregates, which reduce the need for new raw materials during production. 

There are ways to reduce the amount of clinker needed to make concrete and cement, one of the most promising solutions being Limestone Calcined Clay Cement – which can reduce CO₂ emissions by around 40% when compared to traditional cement. Limestone calcined clay cement reduces carbon emissions from clinker production in two main ways. First, it replaces about half of the clinker with calcined clay and ground limestone, materials that do not release carbon when heated the way traditional limestone does. Second, the clay used in this process is heated to a much lower temperature, which requires less fuel and therefore results in fewer emissions. Because the temperature is lower, it also becomes more feasible to use cleaner energy sources, such as electricity, rather than the fuels typically required for clinker production.  

Using recycled materials is another way to reduce the carbon emissions of the construction process. Steel, the most used material in construction, requires high amounts of energy for production. However, using scrap steel can reduce the thermal energy use needed by steel by as much as 75%.  

 Why do they matter?  

The construction industry, largely powered by the production of cement and steel, produces more than twice the carbon dioxide emissions of the aviation sector and contributes additional methane emissions through the use of landfills. In fact, the buildings and construction sector is responsible for roughly 37% of global carbon emissions, making it one of the largest contributors globally.  

A large portion of these emissions comes from embodied carbon, which includes the emissions produced during the extraction, manufacturing, transportation, and installation of building materials before a building is even occupied. Because these emissions occur early in the building lifecycle, reducing them through the use of low carbon materials can have an immediate impact on the footprint of the built environment. 

Low-carbon construction provides an alternative approach by relying on sustainably sourced wood, recycling and reusing materials, and minimizing waste. By reducing reliance on energy intensive materials and incorporating products that store or reuse carbon, the construction industry has the potential to significantly reduce its environmental impact while meeting infrastructure needs. 

 What does the future hold? 

The future of sustainable construction will depend on innovation, collaboration, and policy support across many different sectors. As global demand for buildings continues to rise, the need for low carbon materials will become even more urgent. Researchers estimate that the total floor area of buildings worldwide could double by 2060, which would require massive amounts of new construction if traditional methods remained stagnant.  

Many organizations are already working toward reducing these impacts by promoting net zero carbon buildings and encouraging the use of low carbon materials. The World Green Building Council aims to reduce embodied carbon in new buildings by 40% by 2030 and achieve net zero embodied carbon by 2050. However, the building sector still faces a steep climb toward meeting climate targets, with net-zero buildings currently making up well under 1% of all buildings worldwide. Every building constructed today becomes part of the climate story of tomorrow, making low carbon materials essential for creating a built environment that supports both people and the planet. 

Information from APA Wood, Carbon Leadership Forum, CFP Energy, Statista, UN Economic Commission for Europe, UN Environment Programme, World Economic Forum, World Green Building Council