The Department for Levelling Up, Housing and Communities announced on 30 November 2023 that changes to permitted development rights will allow more homeowners and businesses to install solar panels on their roofs without going through the planning system1. The department said those currently going through the planning system wait over eight weeks and face extra costs1.
Under the changes, homes with flat roofs will be able to install panels without planning permission, bringing the rules in line with those for businesses1. The one megawatt threshold that requires businesses to apply for planning permission for larger rooftop arrays will be scrapped1. The government also said the changes will make it easier to install panels in canopies above car parks, where they are more than ten metres from people's homes1.
Housing and Planning Minister Lee Rowley said:
"By cutting red-tape in the planning system we can make sure homeowners and businesses can install solar panels without being held up by costly delays. Crucially, these permitted development rights are still subject to important conditions, including their use in conservation areas."
Energy Security and Net Zero Minister Graham Stuart said removing the one megawatt restriction for industrial rooftop solar would help meet a target of 70GW of solar power by 20351. The government said the measures support ambitions in the British Energy Security Strategy published the previous year and the net zero by 2050 commitment1.
Installers and advice sites have since described how the change works in practice. Joju Solar states that since the regulation change at the end of 2023, planning permission is not needed for flat roofs, and that on a flat roof the highest part of the solar equipment cannot be more than 600mm above the highest part of the roof, excluding the chimney2. Sunsave states that panels on a flat roof cannot protrude more than 60cm above its surface, and that the highest point of the panels should not surpass the highest part of the roof, excluding objects like chimneys3.
| Requirement | Figure |
|---|---|
| Maximum protrusion, flat roof | 600mm above roof surface3 |
| Maximum protrusion, pitched roof or wall | 200mm2 |
| Gap recommended between array top and ridge | 300 to 400mm2 |
| Perimeter gap, commercial roofs | 1m at edges, base and apex2 |
Spirit Energy, writing in December 2023, said a flat roof system needs at least six panels to be economically viable, taking up 16 to 20 square metres at a standard panel size of 1.8m by 1.1m, with 0.6m to 1.5m of spacing from roof edges for safe edge protection4. It said flat roof installations need extra racking and ballast, and advised a structural survey4. Sunsave states that the vast majority of residential flat roofs in the UK are not suitable for solar panels, that a ballasted panel can weigh around 100kg against about 20kg for a non-ballasted panel, and that it does not currently offer flat roof installations3.
Why it matters for households
For a household, the change removes a planning application, its fee and a wait of over eight weeks for flat roof installations, and confirms that roof-mounted panels on houses remain permitted development in most cases1. The conditions that remain are the ones that shape what a home can actually host: the 600mm height limit on flat roofs, the 200mm limit on pitched roofs, and the position of panels relative to the highest part of the roof3. Conservation areas and World Heritage Sites carry an extra restriction, in that panels must not be fitted to a wall fronting a highway, and an Article 4 direction can remove permitted development rights altogether2.
The practical limit on flat roof solar is structural rather than legal. Ballast adds substantial weight, and the sources disagree on how often residential flat roofs can take it: one installer treats flat roof work as routine subject to a survey4, while another states most residential flat roofs are unsuitable and that the change mainly matters for commercial buildings3. Where a flat roof can take an array, the achievable tilt of around 10 to 15 degrees is well below the roughly 35 to 40 degrees described as optimal in the UK, so output per panel is lower than on a pitched roof3. For a household weighing up solar panels and energy independence, the planning change widens what is possible without permission but does not change the roof's strength, its shading or its available area.
What happens next
The government said the changes build on the Levelling Up and Regeneration Act, which is now law1. No commencement date, transitional arrangements or statutory instrument for the new rights is given in the announcement, and no further timetable has been reported1.
Sources5 cited
- New planning rules to boost solar rollout and slash energy bills - GOV.UK, gov.uk
- Planning Permission for Solar Panels – Joju Solar, jojusolar.co.uk
- Solar panels on a flat roofs: an expert guide UK, 2026, sunsave.energy
- Planning Permission for Flat Roof Solar Panels., blog.spiritenergy.co.uk
- The best angle and direction for solar panels UK, 2026, sunsave.energy