Planning is one of the first questions on any commercial solar project — and since a rule change in late 2023, the answer in England is usually better than people expect. Here’s the position, and where the exceptions still bite.
Rooftop solar is usually permitted development
In England, solar on the roof (or walls) of a commercial building falls under permitted development rights — meaning no planning application, provided the installation meets the conditions. The significant change came in December 2023, when the Government removed the previous 1MW capacity cap for rooftop solar on non-domestic buildings. Large warehouse, factory and distribution roofs — exactly the buildings with the best solar potential — can now be fully panelled under permitted development.
The same change eased the rules for flat roofs: panels may now protrude up to 0.6 metres above the highest part of the flat roof plane (previously 0.2m), which accommodates the tilted mounting frames flat-roof arrays actually use. On pitched roofs, panels must still sit close to the roof plane.
The exceptions that still apply
Permitted development is conditional, and a handful of situations still require an application:
- Listed buildings — always require consent.
- Conservation areas and other designated land — additional restrictions apply, particularly for installations visible from a highway.
- Physical conditions — panels must not protrude beyond the limits above or extend past the roof edge; installations must be removed when no longer needed.
- Ground-mounted arrays at commercial scale normally require a full planning application — permitted development for stand-alone solar is limited to very small installations.
None of these rule a project out; they change the route. Novalux has delivered projects across the UK through both permitted development and full applications — including farm and agricultural sites where ground-mount and rooftop combine.
Wales and Scotland differ
The rules above are England’s. Wales and Scotland run their own permitted development regimes — broadly similar in spirit, different in detail. With our head office in Monmouthshire we work on both sides of the border, and we confirm the applicable regime for every site as part of the design stage.
Other consents worth knowing about
Planning is not the only consent on a commercial project. The DNO grid connection is a separate approval with its own timeline — usually the longer of the two — and buildings with unusual roof structures need a structural assessment before design is finalised. We run all three in parallel from day one so none of them becomes the critical path.
Checked for your site, not assumed
Every Novalux proposal states the consent route for your specific building — permitted development or application, England or Wales — before you commit. Request a Quick Quote and we’ll include it.