Climate change – material selection matters

As a specification writer and architect, I spend a good deal of my time reviewing and learning more about new and existing building materials. But my real passion is finding materials that support and push sustainable design forward. I use my expertise and passion to help project teams make their projects greener and ultimately combat climate change.

Architects may be wondering “what can I do to reduce the embodied carbon in the buildings I design?” The answer is simple. Through careful and thoughtful selection of the materials that are incorporated into our buildings, you can have an impact on the embodied carbon emissions.

It seems almost everything I read today incorporates a discussion on climate change, meaning that it is on the minds of more and more people. Greenhouse gases, of which carbon is the most dangerous, is often linked to global warming. Carbon emissions are produced in two ways: through the manufacture, transport and creation of building materials, known as embodied carbon, and through the operation of buildings, known as operational carbon.

The United Nations Environment Program estimates that 39 percent of energy-related carbon emissions is produced by buildings on an annual basis. Much has been written about operational carbon emissions, that is day-to-day energy use that powers our building lighting, heating, and cooling.  Embodied carbon, it is estimated, results in 11 percent of carbon emissions.

So, ‘how does an architect go about reducing the embodied carbon in the buildings they design’? It’s my opinion that selecting materials with lower embodied carbon is the best way.

Let’s consider the embodied carbon content of some of the most used building materials. For example, concrete, the most used building material whose main ingredient is cement, has a high embodied carbon content. Cement accounts for 8% of the world’s carbon emissions. On the other hand, concrete, is a good insulator, slowing the rate at which a building cools down and warms up.

Likewise, steel is widely used in building construction today. Steel depletes a non-replaceable resource and releases greenhouse gases. While the embodied carbon in steel is high, it is easily and widely recycled. This keeps steel out of the landfill and reduces future impact on climate change.

We also need to consider wood in any conversation about embodied carbon. Wood is one of the earliest materials used in constructing buildings. Wood sequesters carbon naturally and produces lower greenhouse gases than other building materials. The use of wood also reduces the need to burn fossil fuels to produce the products that go into a building.

As the industry’s understanding of embodied carbon and how it can impact the selection of building materials increases, architects will need to make the appropriate choice of materials for future building projects. We will also have to get creative in the way we use various types of recycled materials. Doing so will contribute to the reduction of carbon emissions and extend the lifespan of existing building materials while diminishing the need to produce new materials.

The selection of materials that goes into our buildings matters and we can contribute to a reduction in embodied carbon through thoughtful and careful selection.  

Ross G. Spiegel, FAIA, FCSI, CCS, CCCA, LEED AP