Permitted development for farm solar in 2026: what’s covered, what isn’t

Most farm-building solar PV in the UK doesn’t need full planning permission — Class A Part 14 of the Town and Country Planning (General Permitted Development) (England) Order 2015 covers most rooftop installs on agricultural buildings as Permitted Development. Knowing where Permitted Development ends and full planning starts saves significant time and cost on every farm project. Here’s the practical guide for 2026.

Class A Part 14 GPDO 2015 — what it covers

Class A Part 14 specifically permits the installation of solar PV on the roofs of agricultural buildings (and on the ground within agricultural curtilage) subject to size and height limits. The key permissions:

• Rooftop installations on agricultural buildings: Permitted, no planning permission required, subject to: (i) the panels do not protrude above the ridge of the roof; (ii) the panels do not project more than 200mm from the roof slope (most modern racking systems comply); (iii) the building is genuinely agricultural in use (not residential conversion, not a farmshop with retail focus, not equestrian-only if the equestrian use isn’t agricultural)
• Ground-mounted installations: Permitted within agricultural curtilage, no planning required, subject to: (i) total area of all ground-mount on the holding not exceeding 9m × 9m × 4m height; (ii) the installation is more than 5 metres from any boundary; (iii) the panels are removed within 25 years.

These are the headline permissions. Class A Part 14 covers the vast majority of farm-building rooftop installs and most small ground-mount projects.

What ISN’T covered by Permitted Development

The following situations need full planning permission:

1. Listed buildings — any rooftop PV on a listed building (including listed agricultural barns, dairy parlours, threshing barns, granaries) requires Listed Building Consent. Listed Building Consent timelines typically run 8–14 weeks and require a conservation officer site visit. Many farms have one or two listed buildings within an otherwise unlisted estate — the listed buildings will need separate consent, but the unlisted buildings remain under Permitted Development.

2. National Parks and AONBs — Permitted Development still applies, but local authorities can issue Article 4 directions removing the PD right for specific landscape features. AONBs and National Parks vary in how aggressively they use Article 4. Check with the planning authority before assuming PD applies. Cotswolds AONB, South Downs National Park, Lake District National Park, and Snowdonia National Park have different practical positions.

3. Conservation Areas — Permitted Development applies but the council may consult on visual impact. Conservation officers often have a soft view on agricultural-building PV but will engage on specifics like panel colour and mounting profile.

4. Ground-mount above 9m × 9m × 4m — full planning permission required. For ground-mount installations above 1 MW, an Environmental Impact Assessment is typically also required.

5. Buildings not in agricultural use — barn conversions to dwellings, farm shops with significant retail focus, equestrian centres operating as pure leisure (not agricultural), former farm buildings in commercial use (offices, light industrial). These need full planning permission as commercial PV.

6. Curtilage of listed farmhouses — if PV is on a building within the curtilage of a listed farmhouse, Listed Building Consent may be required even if the agricultural building itself isn’t listed. Conservation officer engagement is essential.

How to confirm Permitted Development

The practical sequence for any farm PV project:

1. Establish building use — is the building genuinely agricultural? Check the rating record, planning history, and current use.
2. Check for listing — search the Historic England National Heritage List for England, Cadw for Wales, Historic Environment Scotland for Scotland.
3. Check for designated landscape — confirm whether the building is within an AONB, National Park, Conservation Area, World Heritage Site, or similar.
4. Check for Article 4 directions — query the local planning authority for any current Article 4 directions covering the building.
5. Confirm size and orientation — ridge height, panel projection from roof slope, total ground-mount area.

If all five confirm Permitted Development applies, the install can proceed without planning permission. We handle this assessment for every project as part of the feasibility stage — typically a 1–2 day desk exercise.

Pre-application advice

For borderline cases (listed building near agricultural building, AONB location, large ground-mount), pre-application advice from the planning authority is worth the £200–£500 fee and 4–6 week wait. The pre-app response gives a clear position the council can be held to during a subsequent full application.

Devolved differences

Wales has its own General Permitted Development Order (Town and Country Planning (General Permitted Development) (Wales) Order 1995 as amended) — similar to England but with subtle differences. Scotland has the Town and Country Planning (General Permitted Development) (Scotland) Order 1992 as amended — slightly more generous for agricultural PV. Northern Ireland has the Planning (General Permitted Development) Order (Northern Ireland) 2015. Cross-check the right framework for the building’s location.

Common pitfalls

Things we see go wrong on farm PV planning:

1. Treating a building converted to residential as still agricultural — it isn’t; PV would need full planning permission as domestic PV.
2. Assuming PD applies on a listed farm building — Listed Building Consent is required regardless.
3. Underestimating Article 4 in AONBs — always check the specific landscape authority’s position.
4. Going ahead without checking conservation officer’s view on visual impact — typically resolved with minor design changes if engaged early.
5. Building exceeds the 200mm panel projection limit — uncommon with modern racking but possible on older corrugated profiles.

We handle the planning workstream on every project as part of our standard scope, including pre-application engagement, Listed Building Consent submission where required, and conservation officer liaison. Most farm-building rooftop installs proceed without any planning involvement — but knowing when planning is needed (and getting started early) avoids costly delays.