Here’s how buildings contribute to climate change – and what can be done about it

As nations continue to submit updated national climate plans intended to put the world on track to meet the goals of the Paris Agreement, here are five things you should know about the buildings and construction sector, and its role in climate change. 

1. The building and construction industry is a big emitter of planet-warming greenhouse gases 

The sector accounts for 32 per cent of global energy consumption and 34 per cent of carbon dioxide emissions, finds the Global Status Report. That is more than transport and agriculture.  

There is some good news, though. In 2023, emissions plateaued, even though emerging and developing countries added 51 billion square metres of new floor space, an area almost 500 times the size of Paris. This is a result of two things. Firstly, buildings are becoming more efficient: the amount of energy consumed per square metre globally fell by 10 per cent between 2015 and 2023. Secondly, the share of renewable energy used in buildings jumped 5 percentage points. However, these numbers are far short of the Paris Agreement-related targets set for the industry. 

“The sector is making progress, but given the scale and rapid advance of the climate crisis, emissions need to drop faster,” says Gulnara Roll, Chief of UNEP’s Climate Change Mitigation Branch.  

2. Building energy codes can help reduce emissions but they need to be twinned with other policies 

A growing number of countries are using building codes as a cost-effective way to reduce the carbon dioxide emissions that come from the operation of buildings. Some 85 countries now have these codes, which cover things such as energy efficiency and the use of renewable energy. But of nearly 51 billion square metres of floor space newly constructed in emerging and developing economies, over 50 per cent remains uncovered by building codes. Roll says that while increasing the use and strength of energy building codes is crucial, gaps will remain unless the sources of other emissions are considered.  

3. The world needs to embrace building materials that are more climate friendly 

Many building-related emissions come from the extraction of natural resources used for construction. As well, the production of materials like cement and steel is responsible for 18 per cent of building-related carbon dioxide emissions. To change that, countries need to develop a more circular construction industry. In practical terms, that can mean using recycled construction materials and retrofitting instead of demolishing older buildings.  

Meanwhile, Roll says the construction industry needs to shift wherever possible to low-carbon building materials, such as sustainably sourced bricks, bamboo and agricultural waste, like straw.  

“At the same time, the world must radically decarbonize conventional materials, such as concrete, steel, aluminum and cement,” she adds.   

4. Traditional building practices can also help reduce emissions 

Traditional building practices have a lot to offer, particularly in countries in the African region where 70 per cent of the building stock expected by 2040 has not yet been constructed. Africa as a region is rich in sustainable materials—from bamboo to termite mound soil—and has a long history of using construction techniques that provide natural heating and cooling, saving money and energy.  

These traditional methods lower energy use and help re-enforce the cultural heritage of communities, says Roll. “They are a win-win, which is exactly the type of thing the world needs right now, given how quickly the building and construction sector is growing.” 

The Sectoral Solution to the climate crisis        

UNEP is at the forefront of supporting the Paris Agreement goal of keeping global temperature rise well below 2°C, and aiming for 1.5°C, compared to pre-industrial levels. To do this, UNEP has developed the Sectoral Solution, a roadmap to reducing emissions across sectors in line with the Paris Agreement commitments and in pursuit of climate stability. The six sectors identified are: energy; industry; agriculture and food; forests and land use; transport; and buildings and cities.