Solar panels and permitted development: what changed in August 2026.

The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2026 came into force on 27 August 2026, and it rewrites the permitted development rights for domestic solar in Part 14 of the GPDO. The headline is reassuring: most straightforward solar installations still do not need planning permission. But the limits are now split between houses and blocks of flats, spelled out in more detail, and a handful of situations that used to be permitted development no longer are. This sets out what actually changed. It reflects the position at the time of writing, so you should always check the current rules for your property.

Panels fixed to the building

For solar PV or solar thermal panels fixed to a wall, a balcony or roof enclosure, or a roof, permitted development now depends on exactly where they sit. On a wall, panels cannot protrude more than 0.2 metres where the wall fronts a highway, or 0.4 metres in any other case, and the same 0.2m / 0.4m split applies to panels on a balcony or roof enclosure. On a pitched roof, panels cannot protrude more than 0.2 metres beyond the roof slope, and cannot sit higher than the highest point of the roof, excluding the chimney. On a flat roof, panels cannot be more than 0.6 metres higher than the roof. These limits now apply separately to houses and to blocks of flats, where previously one set of rules covered both.

Stand-alone and ground-mounted solar

Stand-alone solar within the curtilage of a house, such as a ground-mounted array in the garden, is governed by a height table based on how close it sits to the boundary and to the house:

Where more than one row applies, the lowest height limit wins. Stand-alone panels are also capped at 9 square metres of surface area, and are not permitted development at all within a World Heritage Site close to the boundary or the highway, within the curtilage of a listed building, or on a scheduled monument.

A new trigger for prior approval

For the first time, some stand-alone solar now needs a prior approval application before work starts, even though it remains permitted development in principle. This applies where the installation would sit in a conservation area and nearer the highway than the house, or where it would sit on land such as a National Park, National Landscape or World Heritage Site and within 5 metres of the boundary. In these cases, the council must be asked to determine whether its prior approval is needed for the visual impact of the installation before it goes ahead.

Listed buildings are excluded entirely

This is the change most relevant to the buildings we work on. Solar, whether fixed to the building or stand-alone in the curtilage, is no longer permitted development on a listed building in any circumstances. That applies equally to a listed dwellinghouse and a listed block of flats. A solar installation on a listed building now needs full planning permission and, because it affects the building's character, Listed Building Consent too, which we cover in full in our guide to works on listed buildings. Conservation Areas and World Heritage Sites are not excluded outright, but panels cannot be fitted as permitted development on a wall, balcony or roof enclosure that fronts a highway, and scheduled monuments are excluded completely, in the same way as listed buildings.

A 12-month transitional period

If your planned installation was permitted development immediately before 27 August 2026, but would no longer qualify under the new rules, you are not immediately caught out. The Order allows that previously permitted development to still go ahead under the old rules until 26 August 2027. If you had solar plans in progress before the change, it is worth checking now whether you fall into this transitional window, since the grace period runs for one year only.

Where we come in

Solar increasingly comes up alongside extensions, new houses and listed building projects, and it is easy to assume it is a minor add-on that will not need a separate look. We check any proposed installation against the current limits as part of the wider planning strategy for a project, so it is factored in from the outset rather than discovered as a problem once panels have already been ordered.

Common questions

Can I still fit solar panels without planning permission?

Usually yes, most roof-mounted and stand-alone solar still falls within permitted development, but the limits on protrusion, height and location are now tighter and more detailed than before, and split between houses and blocks of flats. Checking your installation against the current limits before work starts is the safest approach.

What if I already had solar panels approved as permitted development?

There is a 12-month transitional period. If your installation was permitted development immediately before 27 August 2026 but would no longer qualify under the new rules, you can still carry it out under the old rules until 26 August 2027.

Can I fit solar panels on a listed building?

Not as permitted development, in any circumstances, whether the panels are fixed to the building or stand-alone within its curtilage. You will need full planning permission, and because it affects a listed building, Listed Building Consent as well.

Does a conservation area affect solar panels?

Yes. Panels cannot be fitted as permitted development on a wall, balcony or roof enclosure that fronts a highway in a conservation area or World Heritage Site, and a stand-alone array in a conservation area now triggers a prior approval application if it would sit nearer the highway than the house.