The global buildings sector currently contributes a third of greenhouse gas emissions (12.3 GtCO₂ in 2022), according to the International Energy Agency. This comes from the use of fossil fuels for heating, cooling, cooking, lighting, powering appliances, and constructing residential and commercial buildings.

There is not a one-size-fits-all solution for decarbonising the sector, as different solutions work for different building types, countries, and climates. However, the ETC report identifies three critical priorities: electrification, dramatic improvements in energy efficiency, and constructing efficient and low-carbon buildings. These strategies are crucial to creating a sustainable future and meeting global climate goals, it says.

Electrification is the cornerstone of the report’s decarbonisation strategy, and involves replacing fossil fuels used for heating and cooking with electric solutions. Currently, gas and oil heating alone contribute 8% of global emissions, totalling 3 GtCO₂, notes the ETC. Transitioning to electric and efficient technologies such as heat pumps and electric hobs, combined with the ongoing decarbonisation of electricity generation, is crucial, it says. By 2050, the ETC projects that 80% of the energy used in buildings could be electricity, significantly reducing annual emissions from building operations if the electricity supply is decarbonised.

Improving energy efficiency is another critical factor. The rising use of air conditioning, coupled with the electrification of heating and cooking, could almost triple electricity demand for buildings by 2050, from 12,800 TWh to approximately 35,000 TWh, warns the report. However, by enhancing the technical efficiency of heat pumps, air conditioning units and other appliances, improving the energy efficiency of both new and existing buildings, and utilising smart building management systems, this demand could be reduced to around 18,500 TWh.  

The report also calls for the deployment of building-level batteries and other energy storage, smart building control systems and rooftop solar generation. It says these are particularly important for reducing the growth of peak electricity demand, which is a key driver of electricity system costs.

Constructing efficient and low-carbon buildings is also paramount, according to the ETC. New-build construction currently accounts for 7% of global emissions, or 2.5 GtCO₂/y. The global area covered by buildings set to expand by 55% by 2050, predominantly in Asia, Africa and South America. Therefore, maintaining current carbon intensity levels could lead to 75 GtCO₂ emissions by 2050, it warns, based on analysis in Forster et al (2024).

However, these cumulative emissions could be reduced to 30 GtCO₂, suggests the ETC, by using a multifacted approach. This could include decarbonising the production of steel, cement, concrete and other building materials, adopting lightweight and modular construction designs, and better utilising existing buildings via extended building lifetimes and shared working spaces.

The report underscores the importance of ambitious policies to support these transitions. Government policies must combine clear targets to phase out fossil-fuel boilers and cookers, and provide financial support for low-income families and external finance (for example from multilateral development banks) to lower-income countries. Such an approach can overcome the financial barriers that can impede the adoption of low-carbon technologies, particularly for existing buildings, suggests the report.

Adair Turner, Chair of the ETC, emphasises the broader impact of decarbonising buildings: ‘Decarbonising the buildings sector is a story of many transitions. It’s vital for our climate goals and it’s an opportunity to improve living standards and reduce energy costs.’

‘Unless we can radically decarbonise buildings we will fail to keep global warming under 1.5°C outlined in the Paris Accord, continues Stephen Hill, Sustainability and Building Performance Expert at Arup, an ETC member company. ‘To do that we need to make changes all the way through the design, delivery and operation of buildings – from electrification of heating and passive cooling, to reducing embodied carbon emissions for new buildings and refurbishments.’

He concludes: ‘This will require collaboration right across the sector, between governments, industry bodies and private companies. We need to be ambitious, but if we get it right, we can cut carbon, generate value for our economy and improve people’s quality of life through action like improving living conditions and reducing fuel poverty.’