How can we reduce buildings’ embodied carbon emissions and improve energy efficiency at the same time?

By John Mealy, AIA, Director of Sustainability, MBB Architects

As architects confront climate change, we look to the latest advances in building science, HVAC technology, and renewable energy. It’s easy to get the impression that the newest, most sophisticated buildings are the only solution and that the aging building stock of our cities represents a problematic legacy of fossil fuels and inefficiency. This view overlooks the important fact that retrofitting existing buildings to extend their useful life and improve their efficiency can in many cases result in lower overall carbon emissions than a shorter cycle of demolition and reconstruction.

If we view buildings as products we will always be shackled by the limitations of the present, but if we instead see them as processes, they present opportunities for change and adaptation, and the limitations inherent in older construction become assets. Early 20th century buildings in particular have advantages such as optimal window to wall ratios and shallow floor plate depths that make them good candidates for passive strategies. Replacing windows, increasing air tightness and insulation, and electrifying heating systems can allow older buildings to perform as efficiently as new ones. Conversely, even the most energy efficient new construction is responsible for substantial carbon emissions through the sourcing, manufacturing, transportation, and assembly of materials.

Reducing embodied carbon and improving energy efficiency are not mutually exclusive. By embracing the built environment we’ve inherited and building on its strengths, we can do both.

This post was adapted from a brief LinkedIn post for Climate Week