UK Commercial Solar Permitted Development: GPDO Class J Guide

Key Takeaways

• The 1 megawatt capacity threshold for non-domestic rooftop solar PV has been removed (August 2026).
• Flat roof installations must not exceed 0.6 metres above the highest part of the roof (August 2026).
• Pitched roof installations must not protrude more than 0.2 metres beyond the plane of the roof slope (August 2026).
• Installations are prohibited within 1 metre of the external edge of the roof (August 2026).

What are the UK GPDO Class J rules for commercial rooftop solar?

The UK's planning regulations for non-domestic rooftop solar PV have been updated under The Town and Country Planning (General Permitted Development) (England) Order 2015 (GPDO 2015) Schedule 2 Part 14 Class J, as amended by S.I. 2023 No. 1279. These changes, effective as of August 2026, significantly alter the scope of permitted development for commercial solar installations. The most notable change is the removal of the 1 megawatt capacity threshold, allowing larger systems without requiring full planning permission, provided other conditions are met.

The regulations also introduce specific physical limitations on how solar equipment can be installed to manage visual impact. These include restrictions on how high panels can sit on flat roofs, how far they can protrude from pitched roofs, and how close they can be to roof edges.

Key Statutory Provisions for GPDO Class J (August 2026)

Figures as of August 2026.

How we verified these regulations

We verified these provisions by directly consulting the official UK legislation. This included "The Town and Country Planning (General Permitted Development) (England) Order 2015" and "The Town and Country Planning (General Permitted Development etc.) (England) (Amendment) (No. 2) Order 2023" on legislation.gov.uk. Our review was conducted on 23 August 2026. This direct consultation ensures the accuracy of the statutory limitations and requirements presented.

What are the exclusions and limitations for commercial solar permitted development?

While GPDO Class J expands permitted development rights for commercial solar, it includes significant exclusions and limitations. You cannot use permitted development rights under Class J if your site is, or is within the curtilage of, a listed building or a scheduled monument. In these cases, you must apply for full planning permission.

Additionally, solar PV or solar thermal equipment cannot be installed under permitted development on a roof slope or wall facing a highway on Article 2(3) land. Article 2(3) land typically refers to conservation areas, Areas of Outstanding Natural Beauty, National Parks, and the Broads. For installations in these specific locations, full planning permission is required. These exclusions are in place to protect areas of particular environmental or historical significance.

Navigating planning for your commercial solar project

Understanding these permitted development rules is crucial for your commercial solar project. If your proposed installation falls outside the parameters of GPDO Class J, or if your property is subject to the exclusions mentioned, you will need to apply for full planning permission. This process involves submitting detailed plans to your local planning authority and can be more time-consuming.

For a broader understanding of permitted development for commercial solar, consult our UK Commercial Solar Permitted Development 2023 guide. If you are considering solar canopies, our UK Carpark Solar Canopy Permitted Development Class OA Guide provides relevant information. For grid connection requirements, refer to our ENA G99 Type B Standard Connection and Compliance Guide.

You can also use our solar sizing tool to estimate the potential capacity for your commercial property, which can inform your planning application or permitted development assessment. Always ensure your installation complies with all local and national regulations.