What is a heat network and how do they work?

This page sets out what a heat network is, how connections work in the home, and how connecting can enable householders to meet the proposals set out in the Heat in Buildings Bill. 

What is a heat network? 

Heat networks (also known as district heating) supply heat from a central source to consumers, via a network of underground pipes carrying hot water.  

They eliminate the need for individual heating systems and can cover a large area or a small cluster of buildings. There are many renewable sources that can provide the input to a heat network. Examples of these are: 

• Ground source heat pumps 
• Air source heat pumps 
• Water source heat pumps 
• Geothermal energy sources 
• Solar thermal arrays. 

How do heat network connections work in the home? 

Heat is brought into each building through a ‘heat exchanger’ which, for residential homes, is about the same size as a small gas boiler. 

The exchanger heating controls are used like combination gas boilers, both for heating and hot water.  

A benefit of heat networks is that they can be extended over time. New build properties and new sources of heat can be added to the network.  

Once a heat network is available, connecting to a heat network may be one of the cheapest ways to transition to clean heating. As networks are built and expand, the efficiency of the system and potential to save carbon improves over time. 

Connecting to a heat network 

Local Heat and Energy Efficiency Strategies (LHEES) will identify potential heat network zones to enable the setting up of licensed zones.  

Homeowners of properties that sit within such zones will then be able to connect to a heat network. The heat networks will use renewable sources, meaning homeowners can meet the proposed Heat in Buildings Standard by connecting.  

The Scottish Government should support the development of heat networks by encouraging and resourcing local authorities to move forward with implementing their delivery plans once they have completed their Local Heat and Energy Efficiency Strategy (LHEES).  

The Heat in Buildings Bill 

Changeworks has recently submitted our response to the Heat in Buildings Bill Consultation. To read about our response, click here. 

The Heat in Buildings Bill proposes that local authorities and Scottish Ministers will have powers to require developers to connect new buildings to a heat network, wherever possible.  

In London, the model is already driving heat network expansion. Energy firm Vattenfall is partnering with developers to oversee two separate heat networks, the largest of which Vattenfall anticipates will provide 75,000 homes with clean heat by the 2030s.  

In Scotland, Vattenfall have partnered with Midlothian council to deliver heating from a waste heat source to newbuild homes. Other firms delivering heat networks to buildings in Scotland include Vital Energi and Sharc Energy Systems.