UK Commercial Standalone Solar Permitted Development GPDO Class K Guide

Key Takeaways

• Standalone solar arrays under Class K must not exceed 4 metres in height.
• Installations must be at least 5 metres from the curtilage boundary.
• The original 9 square metre area cap was removed by a 2023 amendment (S.I. 2023 No. 1279) — it no longer applies.
• Only one standalone solar array is permitted within the curtilage of a non-domestic building under Class K.

What is GPDO Class K for Commercial Standalone Solar?

The Town and Country Planning (General Permitted Development) (England) Order 2015 (S.I. 2015 No. 596) Schedule 2 Part 14 Class K grants permitted development rights for specific standalone solar installations. This class applies to the "installation, alteration or replacement of stand-alone solar for microgeneration within the curtilage of a building other than a dwellinghouse or a block of flats." This means Class K covers ground-mounted solar arrays for non-domestic premises, including commercial, industrial, and agricultural buildings.

Understanding these regulations helps you determine if your proposed standalone solar project can proceed without needing a full planning application.

What are the Key Limitations for Class K Standalone Solar?

Class K outlines specific statutory limitations and requirements that your standalone solar installation must meet to qualify as permitted development. These provisions cover aspects such as the number of arrays, height, proximity to boundaries, and overall size.

The table below details the statutory provisions for Class K standalone solar equipment on non-domestic premises.

We verified these provisions by directly consulting the Town and Country Planning (General Permitted Development) (England) Order 2015 (S.I. 2015 No. 596) Schedule 2 Part 14 Class K, the primary legal source for these regulations. We accessed and reviewed the relevant sections on 23 August 2026.

When Does Your Project Need Full Planning Permission?

Your standalone solar project will require a full planning application if it exceeds any of the limitations set out in Class K. This includes situations where:

• You propose to install more than one standalone solar array within the curtilage of the non-domestic building. Class K explicitly limits development to a single array.
• Any part of the standalone solar installation would exceed 4 metres in height.
• The installation would be located within 5 metres of the boundary of the curtilage.
• Any single dimension of the array (including any housing) would exceed 3 metres.
• The installation is within the curtilage of a listed building or on a site designated as a scheduled monument. These locations are explicitly excluded from Class K permitted development rights.
• The installation would be nearer to any highway bounding the curtilage than the part of the building nearest to that highway, if the site is on Article 2(3) land.

If your project falls into any of these categories, you must apply for full planning permission from your local planning authority.

Related Permitted Development Guides

Understanding the specific rules for your project type is crucial. We have other guides that may be relevant if your project differs from the Class K scope:

• For standalone solar installations on domestic properties, consult our guide on UK Standalone Solar Permitted Development GPDO Class B.
• If you are considering solar panels on the roofs of commercial buildings, refer to our guide on UK Commercial Solar Permitted Development GPDO Class J.
• For solar canopies in car parks, see our guide on UK Carpark Solar Canopy Permitted Development Class OA.

Always ensure your proposed installation complies with all relevant planning legislation.