The Welsh Government has unveiled plans to effectively make rooftop solar mandatory for new buildings.
Changes to Wales’ building regulations will require “a system for the generation of renewable electricity” to be installed on site in any newly constructed residential building, or in any building “containing a dwelling”. In practice this will mean that in the vast majority of cases solar energy will be installed on roofs as it is the cheapest and easiest technology to install.
The change will come into effect on March 4, 2027, with refined guidelines expected later this year.
“This is great news for Wales and I applaud the Welsh Government for its sensible decision,” said Chris Hewett, CEO of Solar Energy UK. “Solar Energy UK has long lobbied for solar to become virtually mandatory for new homes and buildings, meaning bills will soon be much lower than they would otherwise be.”
In response to the amendment, Solar Energy UK said the upcoming clarifications should “avoid encouraging the installation of ‘token’ systems of just a few panels” and link construction incentives to the availability of electrical connections in a given area.
The lobby group broadly praised the law, saying it “strongly encourages developers to install more than the bare minimum required to comply with the law” as installations will count towards energy efficiency requirements and energy performance certificate assessments.
The Welsh Government’s move echoes the Future Homes Standard and Future Buildings Standard in England, which have pledged as much require solar energy or other renewable energy sources on the roof of new-build homes throughout the country.
The Labor government has previously promised this “unleash a revolution on solar roofs”but publication of the FHS – which has been in the works for years – has been repeatedly postponed.
The standard was expected to be published in January, when the government was introduced to it accusations of decline on reports that domestic energy storage systems will not be included in the mandate for new construction homes. The mandate plans caused some friction between housing developers, the renewable energy sector and the government’s decarbonization goals, as including batteries in the mandate would impose upfront costs for developers.
In March 2025, Solar Energy UK published figures showing this four in ten new houses built in England were equipped with solar energy on the roof.
