A rooftop solar installation on a terraced house in Wales. Next year onward, new buildings in Wales will sport solar panels as the mandatory renewable energy requirement takes effect. (Illustrative Photo; Photo Credit: Ceri Breeze/Shutterstock.com) 
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Wales To Make Solar Panels Mandatory On New Buildings From March 2027

New rules align with England’s upcoming Future Homes and Future Buildings standards, says Solar Energy UK

Anu Bhambhani

  • From March 4, 2027, all new buildings in Wales will be required to install on-site renewable energy systems, effectively making solar panels standard 

  • From a year later, the rule will also cover renovations such as new roofs or changes in building use 

  • Systems producing less than 720 kWh per year or buildings with limited grid connections will be exempt, but developers are encouraged to install more capacity than the minimum 

  • The move is expected to lower bills for occupants, improve energy ratings, and set a precedent for similar rules across the UK, says Solar Energy UK 

Wales is set to become the 1st part of the UK to effectively require solar panels on new buildings, with the rule taking effect from March 4, 2027. It will apply to all new homes and non-domestic buildings where construction has not yet started. A year later, the requirement will also cover renovations such as new roofs or changes in building use.  

Local solar industry group Solar Energy UK said the move sets a precedent for the rest of the UK, which is expected to adopt similar standards in the future. 

The decision follows the Welsh government’s amendment of Part L of its Building Regulations that introduces new energy efficiency measures mandating the on-site installation of a renewable electricity generation system. Although the official regulations do not specify solar power, Solar Energy UK says that the requirement of an on-site renewable energy system means that rooftop solar will be deployed in virtually every circumstance since solar is the cheapest and the most practical way to comply with the rules.   

As per the new rules, the renewable energy requirement will be implemented as a functional requirement of building regulations.  

Instead of ‘token’ systems being installed to comply with the order, the government specifies that if a rooftop solar system with a minimum annual output of 720 kWh cannot be installed, the rules won’t apply. Similarly, buildings with limited grid connections will also be exempt from the ruling.  

At the same time, it encourages developers to go beyond the minimum requirements to lower bills for occupants, improve energy ratings, and meet energy efficiency requirements.  

These rules are on the same lines as the Future Homes Standard and Future Buildings Standard in England that will mandate solar panels on new homes and buildings (see New England Homes To Have Solar Panels ‘By Default’). 

Solar Energy UK’s Chief Executive Chris Hewett said, “This is tremendous news for Wales and I applaud the Welsh Government for their wise decision. Solar Energy UK has long lobbied for solar power to be all but mandatory on new homes and buildings, which will soon see far lower bills than would otherwise have been the case.” 

MCS Foundation has also welcomed the Welsh government announcement, calling it an ‘extremely positive step forward’, which sets a path for the UK and other devolved national governments ‘can and should follow’. 

“Research from The MCS Foundation found that mandating solar panels as well as heat pumps or connections to low-carbon heat networks would save a household living in a typical new-build over £1,000 a year,” stated the MCS Foundation. “As well as financial savings, there would be benefits for grid flexibility, lower carbon emissions, and the domestic renewables industry.”