For the first time since 2020, building emissions have decoupled from rising carbon emissions (CO₂), per an annual report by the United Nations Environment Program (UNEP) and the Global Alliance for Buildings and Construction.

The analysis of the buildings and construction sector found that 2023 was the first year when continued growth of building construction separated from plateaued greenhouse gas emissions. This was due to various measures, including stricter building energy codes, required performance standards, energy-efficient retrofitting of existing buildings, waste management, and low-carbon materials, among other measures.

As a result of those measures, the built environment’s energy intensity was reduced by almost 10%, while the renewable energy share in final energy demand increased by nearly 5%.

“The buildings where we work, shop and live account for a third of global emissions and a third of global waste,” says UNEP executive director Inger Andersen. “The good news is that government actions are working. But we must do more and do it faster. I encourage all countries to include plans to rapidly cut emissions from buildings and construction in their new nationally determined contributions.”

The report notes that despite the progress, buildings remain a key driver of emissions, contributing around 34% of global CO₂ emissions. It also highlights a decline in effective energy reduction measures. Furthermore, the report says that building codes do not cover 50% of newly constructed floor space in emerging and developing economies.

The report’s authors state that while modest improvements have been made, the built environment is not on track to align with net zero carbon and climate resilience targets by 2050 as progress “remains slow and fragmented.”