Buildings emit carbon in two ways: through daily use (known as operational carbon emissions) and via the manufactured cement, steel, and iron used to make them (known as embodied carbon emissions).
Operational carbon emissions can be reduced over time by taking steps like installing a more energy-efficient HVAC system or swapping out a gas furnace for one that runs on electricity from a decarbonized power grid. Today, these operational emissions comprise about 10 percent of total greenhouse gas (GHG) emissions. Embodied carbon emissions, by contrast, are locked in place as soon as a building is built. That means, ultimately, we can’t decarbonize the buildings sector without getting the manufacturing sector to net-zero at the same time.
To reduce building emissions, we need policies that drive deployment of new technologies, such as low-GHG building materials and ultra-efficient heat pumps, and that create incentives for the electrification and improved efficiency of clean technologies that already exist. These policies should also seek to incentivize emission reductions in low-income and historically disadvantaged communities where maintenance issues and split incentives between tenants and landlords have hampered efficiency gains.
Buildings Policy Focus Areas
A primary source of emissions in the building sector is the combustion of fossil fuels for temperature control and appliances. Air-source heat pumps for heating and cooling, electrified appliances, and building electrification through clean energy can all speed the journey to net-zero emissions.
When buildings operate more efficiently, they consume less energy, reducing GHG emissions on a per unit basis. Building-efficiency strategies include replacing old equipment and using sensors and energy management software to optimize a building’s emissions and energy use.
Since embodied-carbon emissions originate from the top of the construction supply chain, we need to develop and use low-carbon materials in building construction wherever possible. Smart low-carbon design strategies, such as optimizing and reusing materials, can further reduce these emissions.