There are few information sources available to help consumers get a sense of the cost of heat networks compared to an alternative. We've developed the Heat Cost Calculator to give consumers access to better information on the cost of their heating and hot water needs against a common alternative.

The Heat Cost Calculator is operated by Heat Customer Protection Ltd, who manages Heat Trust.

The Heat Cost Calculator compares against gas central heating as this is the most common type of heating in Great Britain.

However, for a number of homes, particularly high-rise flats or off-gas grid properties, the correct alternative heating system to compare against would be electric heating.

HIU stands for Heat Interface Unit. It's the bridge between the main heat network and the heating pipes in each individual home. On modern heat network schemes, in place of a gas boiler, each property has an HIU. 

The Heat Cost Calculator isn't looking to assess the efficiency of the heat network and so doesn't factor in the performance of the heat network or HIU. It aims only to give a general indication of what you could expect to pay for heating and hot water in a similar sized home that used an individual gas boiler.

The Calculator takes the amount of heat you use (or an estimate if you are unsure) and factors in gas boiler efficiency, repair and maintenance costs, and the cost to replace a gas boiler for a home of your size.

Anyone can use the Heat Cost Calculator, but if you live in a rented home or you don't have an individual heat meter, its results will be less reliable. Different heat suppliers charge consumers for heat in different ways. Some use dedicated bills for some or all elements of heat charges, while others include heat costs as part of overall rent or building maintenance charges. Not all heat networks are metered; unmetered networks will use a different way to share out costs among residents.

Due to the variation in billing methods, the Heat Cost Calculator assumes that a single heat bill is provided. Its results will therefore be most relevant to owner-occupiers that receive a single heat bill from their heat supplier.

The Heat Cost Calculator is a guide, not a bespoke assessment. It's for information purposes only and isn't intended to show whether or not your heat price is fair. If you have any concerns about your heat charge, you should contact your heat supplier directly.

Yes, you can still use the Calculator, but the results will not be accurate as the Calculator will still calculate the annual cost for heating and hot water for a home using a gas boiler.

Yes. If you don't know how much heat you've used, the Calculator will use an estimate based on the size of your home.

Please choose the one that's the closest match.

For a home with an individual gas boiler, gas is received from the national gas network and then used within the home to provide heating and hot water. The costs of servicing the boiler, repairs, insurance and replacement of a boiler are separate additional costs, on top of the gas bill.

For a home on a heat network, all the costs associated with heating a home are typically within a single heat bill. This includes the cost of the heat source (e.g. gas, biomass), repair, servicing and maintenance costs, and metering and billing costs.

In order to provide a more like-for-like comparison, we take into account gas boiler replacement, repair and maintenance costs.

All of the quotes used are within two standard deviations away from the mean. This principle is used to remove substantial outliners. The average of the quotes is used by the Calculator.

To make the Calculator as transparent as possible, we've only used publically available data. This allows consumers using the Calculator to understand exactly how the calculation is made. Other analysis has used unpublished data which Heat Trust is not able to verify and consumers cannot access.

The information you provide and the results that the Calculator produces will be held by Heat Trust. We may, as part of a wider project, share results from the Calculator with the Department for Energy Security and Net Zero.

All data is collected and held in line with the Data Protection Act as set out in our data protection policy.

No personal data is collected by Heat Trust.

Yes. We'd welcome feedback on the Heat Cost Calculator, which you can give here.

If you have a problem with the Calculator, try refreshing the webpage. If this doesn't work, please email This email address is being protected from spambots. You need JavaScript enabled to view it..