Planning guide · England
Do you need planning permission for commercial solar?
For most commercial roofs in England, no. Rooftop solar on a non-domestic building is permitted development, and since November 2023 there is no megawatt cap on it. Here is what actually applies, what prior approval really tests, and the handful of cases where a full application is unavoidable.
The short answer
Three facts settle most commercial roofs.
Solar PV on the roof of a non-domestic building in England sits under Class J of Part 14 of the GPDO. Meet the conditions and no full planning application is required — the right is already granted.
The November 2023 amendment removed the old 1 MW generation limit on non-domestic rooftop solar. Your roof area, its structure and your load are now the real constraints, not a number in the legislation.
Installations above 50 kilowatts still need a prior approval application to the local planning authority. It is a much narrower, faster test than full planning — and the principle of the development is not reopened.
The conditions
Permitted does not mean unconditional.
Class J grants the right, but it attaches limits, and if the design breaches one of them, the right simply does not apply and you are into a full application. These are the ones that shape a real commercial layout:
In practice the projection limit and the 1 m perimeter setback are the two that bite. They also happen to agree with good engineering: a low-tilt ballasted array on a flat roof keeps wind uplift and ballast weight down, and an inset perimeter leaves the safe access zone every O&M visit needs. The planning rule and the roof usually want the same thing. Our commercial solar design process starts from both at once.
Above 50 kW
Prior approval is not planning permission.
This is the step most businesses have heard of and almost nobody has had explained. Where a rooftop system exceeds 50 kilowatts, the developer must apply to the local planning authority before beginning development for a determination as to whether prior approval is required for the design or external appearance of the development, in particular the impact of glare on the occupiers of neighbouring premises. That is the entire scope. The authority does not get to reconsider whether solar belongs on the building; permitted development has already answered that. It is a lighter, faster, far more predictable process than a full application, and it is one of the reasons commercial rooftop schemes move quicker than people expect.
We set tilt, row spacing and the perimeter setback so the array sits inside the Class J limits before anything is drawn for submission.
A written description of the development, a site plan, contact details and the fee go to your local planning authority before works begin.
The authority has 56 days to determine whether its prior approval is required and, if so, to give or refuse it. The test is design and external appearance.
Once determined — or once the period expires without a determination — the installation proceeds in accordance with the details that were submitted.
One genuine aviation caveat: where a site falls inside an aerodrome safeguarding zone, the planning authority consults the airport operator, and a glint-and-glare assessment is commonly requested. It is not part of the statutory prior approval test, but it can hold a determination up. If you are near an airfield, commission the study up front rather than in response to a holding objection.
The exceptions
When you do need a full application.
The exceptions are a short list, but each one changes the programme materially, which is exactly why they belong at survey stage and not at installation stage.
Listed buildings
Class J does not apply at all. You need listed building consent, and normally planning permission alongside it. Expect months rather than weeks, a conservation officer in the conversation, and a layout that prioritises concealment — rear or courtyard-facing slopes, no visible cabling on principal elevations, sometimes an unlisted outbuilding or a ground array instead of the main roof.
Scheduled monuments
Also excluded from Class J outright. Works affecting a scheduled monument need scheduled monument consent from Historic England — a separate regime from planning, and one to establish very early.
Conservation areas and National Landscapes
Rooftop solar is not automatically ruled out here — the 2023 amendment relaxed the old restriction on highway-facing slopes — but design scrutiny is heavier and local policy bites harder. Check the designation and the local plan before the layout is fixed, not after.
Article 4 directions
A council can withdraw permitted development rights across a defined area by making an Article 4 direction. Where one applies, the identical works need a full planning application. It takes two minutes to check the authority’s Article 4 mapping, and it is the single most common reason a "PD" job turns out not to be.
Ground-mounted arrays
Stand-alone solar on non-domestic land falls under Class K, and the thresholds are small: no more than 9 m² of panel area, no more than 4 m high, no dimension over 3 m, and at least 5 m from any boundary. Any commercially meaningful ground array is far past that, so it is a full planning application — usually with a landscape and visual appraisal, a glint-and-glare study and, on greenfield, a biodiversity net gain position.
Across the West Midlands the practical pattern is consistent: industrial estates and distribution sheds are almost always straightforward permitted development, while town-centre and older civic buildings are where designation checks earn their keep.
The other application
G99 is not planning, but it often sets the programme.
Anything beyond a very small system needs a G99 application to your distribution network operator before it can export. Across the West Midlands that is National Grid Electricity Distribution. The application carries the system specification, a single-line diagram, protection settings, your MPAN and supply capacity, and any proposed export limit.
Timescales vary enormously and honestly: where the local network has headroom, an offer can come back inside a few weeks; where reinforcement is required, it can run to many months. Two practical consequences. First, apply early and in parallel with the planning route, sequencing them wastes a quarter. Second, an export limit, or even a zero-export condition, is not the end of the business case.
A unit you consume on site is worth roughly three times a unit you export, so a system sized to your half-hourly load barely notices an export cap, and battery storage recovers most of the rest. See how that plays out in the payback maths, and what export is actually worth under the Smart Export Guarantee.
Sequence it properly
Indicative only, real programmes are set by your DNO response and your site. We give you dated milestones after the survey.
What we handle
We prepare and submit the applications.
Planning is part of the job, not an extra you are left to chase. Every Green Tech Hub commercial project is director-led, and the consent route is established at the free Business Energy Survey, before you receive a costed proposal, so the programme in that proposal is a real one. Walk through the full sequence on your journey, or start with the commercial solar overview.
General guidance for England, current at July 2026. Permitted development rights differ in Scotland, Wales and Northern Ireland, and can be withdrawn locally by an Article 4 direction. Your local planning authority is the authority on your site, nothing here is a determination, and we always confirm the position in writing before design is finalised.
Questions
Straight answers.
Anything else. Call and speak to a director, not a sales team.
Do I need planning permission for solar panels on my commercial roof?
In England, usually not. Rooftop solar on a non-domestic building is permitted development under Class J of Part 14 of the GPDO, provided the equipment does not protrude more than 0.2 m beyond a pitched roof plane or sit more than 1 m above the highest part of a flat roof, stays 1 m back from the roof edge, is sited to minimise its effect on the building’s appearance and the amenity of the area, and is removed when no longer needed. Listed buildings and scheduled monuments are excluded, and an Article 4 direction can withdraw the right locally.
Is there still a 1 MW limit on commercial rooftop solar?
No. The Town and Country Planning (General Permitted Development etc.) (England) (Amendment) (No. 2) Order 2023 removed the 1 MW generation limit for solar on non-domestic buildings in November 2023. Large rooftop arrays can now proceed as permitted development, subject to the remaining Class J conditions and the prior approval requirement above 50 kW.
What is a prior approval application, and how long does it take?
It is a narrow consent check, not a planning application. For rooftop installations above 50 kW you apply to the local planning authority before starting work for a determination on whether its approval is needed for the design or external appearance of the development — in particular the impact of glare on occupiers of neighbouring premises. The authority has 56 days. It cannot use the process to reconsider whether solar should be there at all: permitted development has already settled that.
What about listed buildings and conservation areas?
A listed building sits outside Class J entirely: you need listed building consent, normally with planning permission, and the layout has to be designed around concealment. Conservation areas are different — rooftop solar can still be permitted development there since the 2023 changes, but design scrutiny is heavier and Article 4 directions are more common. On either, involve the planning authority early; months of programme are at stake.
Does the DNO grid application count as planning permission?
No — they are entirely separate. The G99 application to your distribution network operator (National Grid Electricity Distribution across the West Midlands) governs how much you may export and what protection is required. It has no bearing on planning, but it frequently sets the real programme: where local network headroom exists an offer can come back in weeks, and where reinforcement is needed it can run to many months. We apply early, in parallel with the planning route.
Does any of this apply outside England?
The permitted development rules described here are the English ones. Scotland, Wales and Northern Ireland each operate their own permitted development regimes with different thresholds. Wherever your site is, the local planning authority is the authority on it — this page is general guidance, not a determination.
Let us check your roof.
A free Business Energy Survey tells you the consent route, the realistic programme and the return, before you commit to anything.
Next: payback, capital allowances and fully funded options.
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