Why planning is the most important tool cities can use to fight climate change

A common theme that runs through most of the case studies from Centre for Cities’ recent report on how cities reduce greenhouse gas emissions is the role played by density. Most of the actions taken in the case studies are underpinned by them being dense urban areas. But why is density so important?  

Density influences how we move 

The way towns and cities build homes influences the transport choices that residents take. On a housing estate of detached houses, the chance of living close to a public transport stop is very low, and the frequency of services to that stop (because of the small catchment) is also likely to be low. The result is that the car is a far more convenient choice for the resident. As such, car ownership in Greater London’s outer local authorities is three times higher than inner local authorities. 

The opposite is the case in high-density areas. In these places, the number of residents in one place helps to ensure that their proximity to a public transport stop is higher, the frequency of service is likely to be higher, and the higher congestion – resulting from more people per square metre of road space – will make car travel slower.  

The result is that the benefits of using active travel and public transport outweigh the car in higher-density places. This helps explain why public transport usage is much higher in London than the rest of the UK, and why more than half of households in inner London do not own a car. 

Density underpins lower-carbon housing and heating choices 

Density also supports lower-carbon housing choices. Smaller houses and flats – more usually found in urban areas – tend to emit less and be more energy efficient than detached homes: new flats emit 67 per cent less carbon than new houses. 

Density is likely to have implications for how we heat homes in the future too. The Government is looking to increase the role that heat networks play in supplying heat to homes through its Heat Network Zoning policy. The density of cities makes connecting buildings to a central heat source easier, with less heat lost in transition. New buildings can be added to the network without the need for large structural changes to the building or network.. 

One further benefit of density is the increased chance of being able to recycle and use heat – through these heat networks – from existing operations like waste facilities, heat from the tube or data centres as has been done in Stockholm, in Sweden.  

Achieving higher densities requires changes to the planning system 

Planning may not seem like a tool to address the climate breakdown but, at the city level, it is perhaps the most important one. This makes planning reform not only important for building the homes that we need, but also to help the UK meet its net zero goals. It also means that if they do want to reduce emissions in their cities, mayors should be taking up the Government’s offer to have spatial planning powers. And through this they should be encouraging their cities to become more dense, focusing on building homes around transport stops to encourage the shift in lifestyles that will be needed to bring emissions down.