Planning Permission for Solar Panels on Commercial Buildings

Do I need planning permission for solar on my business premises?

Three questions settle most cases:

• Where do the panels go?. On the roof of a non-domestic building, permitted development usually applies within limits. In a field or yard, only a tiny array is permitted. Over a car park, there is a separate right for canopies in England.
• Is the building listed, or on a scheduled monument?. If so, permitted development doesn't apply.
• How big is the system?. In England, rooftop systems over 50 kW are allowed, but only after the council's prior approval process.

Planning is separate from building regulations and from the grid connection, which every installation needs regardless. The installer checks all three at the survey.

Permitted development for non-domestic buildings in England

Class J of Part 14 of the General Permitted Development Order allows solar PV on a building that is not a house or block of flats, unless (Class J):

• Pitched roofs. the equipment would stand more than 0.2 metres beyond the plane of the roof slope;
• Flat roofs. the highest part would be more than 1 metre above the highest part of the roof (chimneys excluded);
• Edges. any part would be within 1 metre of the external edge of the roof;
• Protected sites. the building is listed, within the curtilage of a listed building, or on a scheduled monument.

Panels must, so far as practicable, be sited to minimise their effect on the building's appearance and the area's amenity, and be removed when no longer needed. Wall-mounted panels have their own limits.

Over 50 kW: prior approval

The law defines microgeneration as up to 50 kilowatts of electricity (Energy Act 2004, s82). For rooftop solar beyond that, Class J still applies but you must first ask the council whether its prior approval is needed for the design or external appearance, in particular the effect of glare on neighbours (Class J, J.4):

• What you send. A written description, a site plan, a contact address and any fee.
• Neighbours. The council puts up a site notice for at least 21 days or writes to adjoining owners or occupiers.
• When work can start. When the council says approval isn't needed, when it gives approval, or after 56 days with no decision.
• Afterwards. The work must follow the details approved or submitted.

Since the 2023 amendments, Class J sets no upper size limit for rooftop solar on non-domestic buildings. Your installer usually prepares the application. Allow for it in the timetable: see commercial solar system sizes for the other things that change above 50 kW.

Ground arrays and car park canopies

For stand-alone solar at a non-domestic site in England, Class K allows one installation, no higher than 4 metres, at least 5 metres from the boundary, with no more than 9 square metres of panels and no dimension over 3 metres (Class K). A business-scale ground array needs a planning application. See ground mounted solar.

Canopies over non-domestic car parks have their own permitted development right in England, Class OA (Part 14), with height, distance and prior approval rules. See solar carports.

Listed buildings and conservation areas

Listed buildings and buildings in their curtilage are outside permitted development in England, Wales and Northern Ireland, and in Scotland the rights don't apply to listed buildings, so you need planning permission and listed building consent. Panels on an outbuilding, on the ground or over the car park are sometimes easier to agree than panels on the listed building itself.

Conservation areas don't remove the rights for roofs in England, but Scotland, Wales and Northern Ireland restrict panels facing a road there (see below). Councils can also remove permitted development rights with an Article 4 direction, most often in conservation areas (GOV.WALES).

Scotland, Wales and Northern Ireland

Before you start: what to check

• Listing and designations. Whether the building is listed or the site is in a conservation area, National Park or other designated land.
• Your planning history. Conditions on the original permission and any Article 4 direction (on the council's planning register).
• System size. Over 50 kW in England means the prior approval step.
• Your lease. If you rent, your landlord's consent is a separate question from planning. See solar on leased property.