Nesta and the Behavioural Insights Team (BIT) published findings on 14 April 2025 from an online randomised controlled trial testing whether a coordinated approach to low-carbon heating increases uptake among UK homeowners1. The trial ran with 5,525 UK homeowners, split 78% house owners and 22% flat owners, and excluded anyone whose current main heating system was not a gas, oil or LPG boiler1.
Participants chose between a boiler and a low-carbon heating system under two cost scenarios: cost parity, and a discrepancy scenario where the boiler cost £3,000 and the low-carbon system £5,0001. The control group saw the current individual pathway; four treatment arms added variations to a coordinated approach, including a vetted supplier, reduced hassle and additional guidance, a 15% discount, cashback on other home energy efficiency upgrades such as solar panels, insulation or windows, and a 0% interest financing option to spread costs over monthly payments1.
Under cost parity, adoption was similar between the control group (35.1%) and the coordinated switching group (33.6%)1. When the low-carbon system was more expensive, adoption dropped to 23.7% in the control group and 22.3% in the coordinated switching group, a statistically significant fall of 11.4 and 11.3 percentage points respectively1. The only statistically significant increase in uptake came in the spread costs condition, at 39.3% against 33.6% for base coordinated switching1. The 15% discount did not significantly increase uptake in the cost parity scenario, and neither the cashback nor the discount statistically significantly boosted adoption1.
The report found that households with below-median income were statistically significantly more likely to respond to coordinated offers including direct cost reductions, while households with above-median incomes only showed a preference for financing options such as 0% interest plans1. Among reasons given for choosing low-carbon heating, 76% cited it being better for the environment and 66% said they believed the country is heading towards low-carbon and boilers will be phased out1.
"The ease resulting from a coordinated approach alone does not increase the uptake of low-carbon heating; participants were more likely to opt for a coordinated low-carbon heating scheme if it involved financial incentives such as spread costs with 0% interest."
| Condition | Adoption, cost parity | Adoption, low-carbon more expensive |
|---|---|---|
| Control (individual pathway) | 35.1% | 23.7% |
| Base coordinated switching | 33.6% | 22.3% |
| Spread costs, 0% interest | 39.3% | Not reported separately |
Why it matters for households
The findings bear on how home heating and energy independence might be financed at street level. A coordinated scheme that only removes hassle, such as a vetted supplier and shared guidance, did not move adoption in this trial; the mechanism that did was spreading the upfront cost at 0% interest, which matters where a heat pump's headline price sits above a boiler replacement1. The split by income suggests direct cost reductions and financing options reach different households, which is relevant to how interest-free loans and finance schemes for home energy work are designed. The report also notes that participants expected their neighbours to be less likely to switch than they were themselves, and more swayed by financial support, which the authors link to how heat pumps are perceived locally1.
What happens next
The report sets out recommendations rather than dated commitments: flexible financing options with support for equitable uptake, clearer communication and transparency, use of social norms showing community adoption, direct addressing of performance concerns, and messaging on perceived neighbour interest1. No implementation timetable or follow-up trial has been reported.