The short answer: most rooftop solar on existing agricultural buildings in England qualifies as permitted development under Class A and Class B of the General Permitted Development Order (GPDO). Ground-mount above 1 MW, installations on listed buildings, projects within AONBs and National Parks, and arrays visible from public highways generally need full planning permission.
Permitted development (no planning needed)
- ✓ Roof-mounted PV on existing agricultural buildings, England
- ✓ System size below 1 MW
- ✓ Panels do not project more than 200mm above the roof surface
- ✓ Panels do not exceed the highest part of the roof (excluding chimneys)
- ✓ Building is not listed or in a conservation area
- ✓ Site is not within a National Park, AONB, or World Heritage Site
Full planning required
- • Ground-mounted PV arrays above 1 MW (or smaller within sensitive landscapes)
- • Any installation on a listed building (Grade I, II*, or II)
- • Buildings within a conservation area
- • Sites within AONBs, National Parks, or designated heritage settings
- • Projects visible from a public road or right of way where visual impact is material
- • Agrivoltaic schemes combining grazing/cropping with PV (treated as agricultural diversification)
Typical timescales
- Permitted development (prior notification): 28-day determination period — most farms get the all-clear and proceed.
- Full planning application: 8 weeks for most agricultural solar, 13 weeks for major applications (over 1 MW).
- EIA screening (large ground-mount): additional 4–8 weeks.
Devolved variations
Wales: Permitted development rules are similar but governed by the Town and Country Planning (General Permitted Development) (Amendment) Order 2014 (W). Most rooftop ag-solar qualifies. Welsh National Parks (Snowdonia, Pembrokeshire Coast, Brecon Beacons) require full applications.
Scotland: The Town and Country Planning (General Permitted Development) (Scotland) Order 1992 (as amended) covers most agricultural rooftop solar. National Scenic Areas (NSAs) and conservation areas need full planning.
Northern Ireland: Planning controls are devolved to NI Planning Service / DfI. Permitted development for ag-solar is broadly aligned with England but local councils have wider discretion.
We handle the planning
Every project gets a planning assessment as part of the desk feasibility — within 3 working days of you sending us your bill and roof drawing. If permitted development applies, we submit the prior notification on your behalf. If full planning is needed, we coordinate with a chartered planning consultant and engineer the visual impact, ecology, and heritage statements as required. We have a 96%+ approval rate on agricultural solar planning applications.