The Scottish Government has laid a statutory instrument before parliament setting out changes to permitted development rights (PDR) for solar installations, which are expected to come into effect on Friday 24 May, subject to final scrutiny1. The measures follow phase 3 of the Permitted Development Rights review, which covered rooftop and ground mounted solar1.
The most significant change removes the current 50kW limit for permitted development on rooftop solar installations1. Under the existing rules, any rooftop solar PV installation of 50kW, roughly 220 square metres, or greater must be subject to 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 year; 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 carports1. 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. PDR for car ports was introduced in phase 2 of the PDR review last year, but carried a restriction that energy from a solar canopy must be primarily used for charging vehicles; that restriction has now been removed and car ports can have solar added to them under permitted development1.
| Change | Position reported |
|---|---|
| Rooftop solar ceiling | 50kW limit removed1 |
| Conservation areas | Permitted development in certain circumstances, such as not on primary elevations or affronting roads1 |
| Flat roofs | Allowed if not protruding more than 1m from the roof surface1 |
| Car ports | Solar allowed under permitted development; vehicle-charging restriction removed1 |
| Free-standing solar | Allowed within the curtilage of a building, restricted to 12sqm of surface area1 |
Free-standing solar, such as ground mounted solar 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 systems, and the article describes 12sqm as a seriously small amount of solar1. It states there may still be an opportunity for the Scottish Government to reconsider through continued cooperation with Solar Energy Scotland1. No further detail on that process has been reported.
Why it matters for households
Planning consent is one of the fixed costs and delays in a home solar project, and the rules differ across the UK. For a household in Scotland, the practical effect of these changes sits mainly in the removal of the 50kW ceiling, which matters to larger roofs and to multi-unit or commercial buildings rather than to a typical domestic array, and in the relaxation for conservation areas, where rooftop solar previously required full planning in every case1. The flat roof provision sets a clear physical test, a protrusion of no more than 1m from the roof surface, which is relevant to homes with flat or low-pitch 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. Together these rules shape how much generation a household can add without consent, and therefore how far a home can move towards producing its own electricity. The detail of what is and is not permitted sits in the Permitted Development Rights for Home Energy Equipment rules, with the Scottish position set out in Planning Rules for Home Energy Equipment in Scotland and Solar Panel Planning Permission in Scotland.
What happens next
The changes are expected to come into effect on Friday 24 May, subject to final scrutiny1. The statutory instrument was laid before parliament on 28 March1. No further dates have been reported.