Are solar panels (PV) a legal requirement for new homes and commercial projects? The short answer is: it is increasingly likely, but it ultimately depends on which version of Part L Building Regulations your project must comply with.
As the UK moves toward the Future Homes Standard, the requirements for onsite renewable energy are becoming much stricter. Here is the breakdown of how solar PV affects your compliance:
Solar Requirements for Part L 2026 (Future Homes Standard)
For projects assessed under the upcoming Part L 2026 regulations, Solar PV is essentially a mandatory requirement for all new build dwellings and commercial buildings.
- The 40% Rule: You are generally required to install a PV array equivalent to 40% of the building’s total floor area.
- Are there exemptions? Yes. If your roof area cannot realistically accommodate an array of that size, exemptions can be made—provided you provide a valid technical justification within your compliance report.
Solar Requirements for Part L 2021
If your project still falls under the Part L 2021 criteria, you have more flexibility depending on your primary heating source:
- With Air Source Heat Pumps (ASHP): In many cases, you can avoid installing solar PV if you are already using high-efficiency low-carbon heating like an ASHP.
- With Gas or Oil Boilers: If you are still installing traditional boilers, Solar PV will almost certainly be required to offset the carbon emissions and meet your target rates.
Conclusion: Every SAP Calculation is Unique
While solar PV is becoming the standard for most UK new builds, every project is different. Your SAP Assessment is the only way to determine the most cost-effective path to compliance.
Why Choose UK Building Compliance for Your SAP?
Achieving the most efficient way to Part L compliance requires expertise. At UKBC, we don't just provide a report; we provide the support you need throughout the entire process;
- Free Dashpivot App: to make photo evidence requirements as easy as possible
- Technical Assistance: Expert guidance on how to achieve compliance
- Unlimited Specification Revisions: design revisions fully included in the cost
- Integrated Service: We can coordinate your Air Testing directly with your SAP Calculations for a seamless compliance journey.
Need expert advice on your next project?
Contact UK Building Compliance today or use our Quick Quote tool to see how we can help you navigate the 2026 Part L