The Scottish Government laid a statutory instrument before parliament on 28 March 2024 setting out measures to simplify the planning rules for solar installations1. The changes come from phase 3 of the Permitted Development Rights (PDR) review, which covered rooftop and ground mounted solar, and are expected to come into effect on Friday 24 May, subject to final scrutiny1.
The most significant change removes the current 50kW limit for permitted development on rooftop solar1. Under the existing rules, any rooftop solar PV installation of 50kW, roughly 220 square metres, or greater must go through a full planning application1. The same limit in England was 20 times greater at 1MW, about 4,400 square metres, and that upper limit in England was removed in November last year1. Scotland has now followed suit and removed the upper limit1.
"Scotland have followed suit and removed the upper limit"
Other changes cover conservation areas, flat roofs and carports. Previously all rooftop solar in conservation areas required full planning; solar in conservation areas can now be permitted development under certain circumstances, such as not on primary elevations or affronting roads1. Flat roof systems can be installed under permitted development provided they do not protrude more than 1m from the roof surface1. Restrictions that required the energy from a solar canopy to be primarily used for charging vehicles have been removed, so car ports can have solar added to them under permitted development1. PDR for car ports was introduced in phase 2 of the PDR review last year1.
| Measure | Before | After |
|---|---|---|
| Rooftop solar | 50kW limit; 50kW or greater needed full planning | Upper limit removed1 |
| Conservation areas | All rooftop solar required full planning | Permitted development in certain circumstances, such as not on primary elevations or affronting roads1 |
| Flat roofs | Restricted by protrusion requirements | Permitted if not protruding more than 1m from the roof surface1 |
| Car ports | Solar canopy energy had to be primarily for charging vehicles | Restriction removed1 |
| Free-standing solar | Not permitted without full planning application | Allowed within the curtilage of a building, restricted to 12sqm of surface area1 |
Free-standing solar, such as ground mounted panels, will be allowed within the curtilage of a building without a full planning application, but the Scottish Government has restricted this to 12sqm of surface area1. The published consultation analysis was fully supportive of allowing larger systems1.
Why it matters for households
For a household, the removal of the 50kW rooftop threshold matters mainly for larger roofs and for anyone weighing up a system well beyond typical domestic size; the previous figure of 50kW is far above what most homes install, so the direct effect on a single dwelling is limited. The conservation area change is the one most likely to touch ordinary homes, because it moves some rooftop solar in those areas out of full planning and into permitted development, subject to conditions on elevation and visibility from roads1. The flat roof rule gives a clear 1m protrusion limit for systems on flat roofs1. The 12sqm cap on free-standing solar limits what can be installed on the ground within a property's curtilage without a full application1. The rules sit within Scotland's devolved planning rules for home energy equipment, and the wider permitted development rights framework differs across the UK nations, including Wales and Northern Ireland. Where permitted development is withdrawn, for example by an Article 4 direction, a full application is still needed. Households in flats face separate questions, covered in the guide to solar panels on a flat in Scotland, and the protrusion rules for pitched roofs remain relevant to roof-mounted systems.
What happens next
The changes are expected to come into effect on Friday 24 May, subject to final scrutiny1. The Scottish Government has said it will continue cooperation with Solar Energy Scotland, and the article notes a hope that the 12sqm limit on free-standing solar could be reconsidered1. No further dates have been reported.