MCS, the certification body for small-scale renewables in the UK, began tracking installations in self build properties as of February 2025, the organisation said in its review of last year's installation data1. The new category is reported alongside existing breakdowns by property type and build type1.
Self build properties made up 1% of certified installations in 2025, and 4% of all heat pump installations, according to the same review1. The figures sit within a year MCS describes as its strongest to date.
"2025 was the best-ever year for small-scale renewables in the UK"
The wider numbers give the self build share its context. Rooftop solar reached 267,032 certified installations in 2025, surpassing the previous record set in 2011 by 31% and bringing the scheme total close to 2 million1. Heat pump installations passed 60,000 for the first time in a single year, with the Boiler Upgrade Scheme funding nearly half of them1. Battery storage saw more than 40,000 certified installations, almost double the previous record, meaning more than half of all MCS battery installations were completed in 2025 alone1.
New build properties were a significant driver of the record year. Of all installations in 2025, 28% were on new builds, rising to more than 36% for solar alone1. MCS notes that the Future Homes Standard is set to mandate solar panels on new homes1. By nation, England recorded over 280,000 certified installations, up a third on 2024; Wales had almost 33,000, with more than one in ten Welsh households now holding an MCS certified installation; Scotland had almost 40,000; and Northern Ireland more than 2,800, where solar accounted for 94% of installations1.
| Nation | Certified installations in 2025 |
|---|---|
| England | Over 280,000 |
| Wales | Almost 33,000 |
| Scotland | Almost 40,000 |
| Northern Ireland | More than 2,800 |
MCS states that its data may differ slightly from its public dashboard because of the two-week window for commissioning and registering installations1. No further detail on how self build properties are identified in the database has been reported.
Why it matters for households
Self build sits outside the mainstream housebuilding route, and until February 2025 it was not counted separately in MCS data1. Its appearance as a tracked category means installations on self build homes now show up in the same certification statistics as other property types, rather than being absorbed into wider totals.
For a household, the practical relevance is the certification itself. An MCS certified installation is the route by which a system is recorded in the scheme's database, and MCS describes certification as a mark of quality that an installation has been completed to industry-recognised standards and that the products used have been designed and tested1. The self build figures indicate that a small but measurable share of solar PV and heat pump work is now happening on homes built by their owners, and that heat pumps are a larger part of that share than the overall 1% suggests1.
The 4% heat pump figure also points to where self builders are choosing to spend: heat pumps rather than solar, relative to the wider installation mix1. Households weighing installers and certification routes can note that the data now distinguishes this group, though the review does not break the self build numbers down by technology beyond heat pumps.
What happens next
MCS says the Future Homes Standard is set to mandate solar panels on new homes, which it identifies as a key driver of the sector's growth1. The review does not give a date for that standard coming into force. MCS also states that under its redeveloped installer scheme it will contact every consumer to assess satisfaction with their certified installation1.
Sources1 cited
- The 2025 Low Carbon Landscape - MCS, mcscertified.com