The building sector CO₂ emissions in the US have fluctuated since the 1990s but have slightly trended downward as the sector electrifies and uses less oil. In 2017, the sector’s CO₂ emissions accounted for 8% of total US emissions.
Our analysis indicates that direct CO₂ emissions in the building sector would need to decline by 61–73% by 2030 and reach zero by 2034 to 2049. This would be enabled by increased electrification, from about half of the sector’s energy use in 2019 to 70–75% by 2030 and 90–92% by mid-century.
The US does not have a national emissions reduction target or strategy for the building sector; however, several states have adopted policies and several federal programmes exist to improve energy efficiency of buildings. The Inflation Reduction Act (IRA) includes provisions for both new buildings and for the retrofit of existing buildings, such as support for states and local governments to implement more stringent energy codes and incentives for improved efficiency and electrification particularly for low- and moderate-income households.3
17 While global cost-effective pathways assessed by the IPCC Special Report 1.5°C provide useful guidance for an upper-limit of emissions trajectories for developed countries, they underestimate the feasible space for such countries to reach net zero earlier. The current generation of models tend to depend strongly on land-use sinks outside of currently developed countries and include fossil fuel use well beyond the time at which these could be phased out, compared to what is understood from bottom-up approaches. The scientific teams which provide these global pathways constantly improve the technologies represented in their models – and novel CDR technologies are now being included in new studies focused on deep mitigation scenarios meeting the Paris Agreement. A wide assessment database of these new scenarios is not yet available; thus, we rely on available scenarios which focus particularly on BECCS as a net-negative emission technology. Accordingly, we do not yet consider land-sector emissions (LULUCF) and other CDR approaches which developed countries will need to implement in order to counterbalance their remaining emissions and reach net zero GHG are not considered here due to data availability.
18 In some of the analysed pathways, the energy sector assumes already a certain amount of carbon dioxide removal technologies, in this case bioenergy carbon capture and storage (BECCS).
The United Statesʼ energy mix in the buildings sector
petajoule per year
Scaling
SSP1 Low CDR reliance
SSP1 High CDR reliance
201920302040205020 00030 000
Low energy demand
201920302040205020 00030 000
High energy demand - Low CDR reliance
201920302040205020 00030 000
Natural gas
Coal
Oil and e-fuels
Biomass
Biogas
Biofuel
Electricity
Heat
Hydrogen
The United Statesʼ buildings sector direct CO₂ emissions (of energy demand)
MtCO₂/yr
Unit
10020030040050060019902010203020502070
Historical emissions
High energy demand - Low CDR reliance
SSP1 Low CDR reliance
SSP1 High CDR reliance
Low energy demand
1.5°C compatible buildings sector benchmarks
Direct CO₂ emissions and shares of electricity, heat and biomass in the buildings final energy demand from illustrative 1.5°C pathways for The United States