If you’re interested in making your home heating greener and are considering switching to a heat pump, one of the first questions you might ask is how much it will cost to install. The answer to that isn’t clear, especially for people who have little prior knowledge. You might search online and find that a heat pump unit on its own costs about £5,000. On the other hand, you might come across newspaper headlines that suggest it could cost up to £35,000 for a heat pump installation. That’s a big window, and doesn’t tell us much.

We know from our earlier research into heat pump adoption that consumers really want personalised information that helps them understand the technology and how to make decisions. Without it, consumers are put off. Heat pump adoption becomes too complicated and people stick with what they know, which is usually fossil fuels.

Our aim was not to replace the job of professional heat loss surveys and installer quotes, rather it was to see if it’s possible to provide householders with a figure that is within a range which is accurate enough to help them better understand what’s possible and identify what to do next. Providing such information would, we thought, build confidence and encourage more householders to adopt heat pumps.

At the time in 2022, our aim was simply to test the concept and find out if providing such information was possible. There were various parts to this project, and we assembled a mixed methods team including data science, design and analytical expertise to work on it.

We explored the core cost components of a heat pump’s installation which we found by speaking with heat pump installers. We asked them what they look for when they quote for jobs, and about the elements of the final bill. We were keen to learn whether there are particular things that strongly influence the total cost and, if there were, what they were. Knowing this helped us understand cost estimations and produce our own, and we approached this in two different ways.

One way was through the creation of an arithmetical model based on user-collected data from householders themselves. Using the price influences that we identified from our interviews with installers, we wanted to test whether simply collecting a few key pieces of information about a property could predict heat pump installation cost with sufficient accuracy.

Another part of this project was to create a machine-learning predictive model. This drew on data from existing installations from Energy Performance Certificates (EPC) as well as registrations of heat pump installations on the Microgeneration Certification Scheme (MCS) database. We used these to predict how much an installation might cost in a similar property. The model was enhanced by the findings from the heat pump installers, for instance by guiding the model to pay particular attention to some characteristics of a property over others.

We also experimented with the possibility of combining these two elements to see whether mixing user-entered data with the outcomes from the predictive model leads to improved accuracy.

We created an experimental tool powered by the machine-learning predictive model that attracted lots of users, and was featured in key consumer outlets like the BBC and Money Saving Expert. This signalled that our offer had good potential to support people with their needs on their journey towards getting a heat pump

More recently we’ve used user research, data science techniques and software engineering expertise to guide the development of a new version of the tool based on the same underlying data, that also:

• improves the usability, relevance and accuracy of the tool
• enables it to be easily integrated with partners’ own web pages and tools
• enables a better understanding of users’ intended next steps

Find out more about the new tool in our project update.