Permitted Development Rights (PDR) allow certain types of development without applying for planning permission, provided specific conditions are met. For commercial solar PV in the UK, PDR has been progressively expanded over the last decade and now covers most rooftop installations and smaller ground-mount.
For solar on commercial buildings (Class J of the General Permitted Development Order), PDR allows installations subject to the conditions: panels must not protrude more than 200mm from the roof slope, must not be on a listed building or in a conservation area or AONB without separate consent, and must be sited to minimise visual impact.
Following 2024 reforms, the previous 1 MW capacity cap on rooftop solar PDR has been removed entirely for non-domestic buildings. This means even very large rooftop arrays, multi-megawatt installations on logistics buildings or factories, can now be installed under PDR provided the building is not protected and the visual impact conditions are met.
For ground-mount solar, the situation is more limited. Standalone ground-mount on agricultural land is allowed under PDR up to a strict capacity limit, typically 1 MW, with conditions on land take and screening. Above this, full planning permission is required.
A common misunderstanding: PDR doesn't override the need for prior approval. For most non-trivial installations, you still need to notify the local planning authority and they have a defined window (typically 56 days) to require formal planning approval. So while PDR speeds up the process and removes the ability for the council to outright refuse, it doesn't eliminate the planning process entirely.
The grid connection (G99) and Building Regulations process are entirely separate from planning and apply regardless of PDR status.