New Solar Permitted Development Rules: August 2026 Changes

What changed on 27 August 2026

Most homeowners fitting solar panels in England never apply for planning permission, because rooftop solar on houses has long been permitted development under Part 14 of the General Permitted Development Order. From 27 August 2026, those rules change. The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2026 — SI 2026/896 rewrites the solar classes, and because it landed in August 2026 with modest publicity, a lot of what is being said about it online is already muddled.

This guide covers what the Order actually says, what it changes in practice, what it leaves alone, and — because we have already seen the mistake repeated — the one detail that half the early write-ups have got wrong.

One boundary before anything else: this is England-only law. The GPDO 2015 and this amendment apply to England. Scotland and Wales run their own permitted development regimes with their own limits, and any UK-wide website (including this one) should say so plainly rather than quietly assuming English rules cover the country.

The headline change: wall-mounted panels may project 0.4 m

Under the amended Class A, solar equipment mounted on the wall of a house may now project up to 0.4 metres beyond the plane of the wall — double the previous 0.2 metre allowance. The old, tighter limit is retained in one situation: where the wall fronts a highway, the projection limit stays at 0.2 metres.

That sounds like a small dimensional tweak, but it changes what is buildable without an application. At 0.2 metres, wall-mounted solar was largely limited to flush or near-flush panels. At 0.4 metres, properly bracketed wall arrays — including panels angled off a gable or south-facing wall to improve their pitch — become realistic as permitted development on many houses. For homes with poor roof orientation, limited roof area, or a strong gable catching good sun, the wall just became a genuinely usable surface. Vertical and steeply-mounted panels also carry a quiet advantage UK buyers rarely hear: they perform relatively well in winter, when the sun is low and demand is high.

The detail everyone is getting wrong

Several early summaries of SI 2026/896 claim that panels on a roof may now project 0.4 metres from the roof slope. The text of the Order says otherwise. The 0.4 metre allowance applies to walls. For pitched roofs, the amended wording keeps the familiar limit: equipment must not protrude more than 0.2 metres beyond the roof slope, and must not sit higher than the highest part of the roof (excluding the chimney).

In practice the 0.2 metre roof limit is rarely a problem — a standard on-roof array on rails sits around 0.1–0.15 metres proud of the tiles — but the distinction matters if you are reading claims that “roof rules were relaxed” and planning a system around them. They were not. If a design genuinely needs more than 0.2 metres off the roof slope, it needs a planning application, exactly as before. When a rule is one click away on legislation.gov.uk, read the rule rather than the write-ups — this one takes two minutes.

Houses and flats are now treated separately

The second structural change: the amended Order splits the solar rights in two, with one set of rules for houses and a separate set for blocks of flats (the flats wording largely carrying over the previous regime). Until now, houses and flats shared a single set of conditions. From 27 August 2026, the more generous house allowances do not automatically read across to a block of flats — so if you own or manage a flat, check the flats-specific wording rather than assuming the house rules apply. For leaseholders the practical position is unchanged in another way too: permitted development rights remove the need for planning permission, not the need for your freeholder’s consent.

What stays the same

Just as important as the changes is the long list of things the Order leaves alone:

• The flat-roof limit stays. Solar on a flat roof of a house must not sit more than 0.6 metres above the highest part of the roof. Ballasted domestic flat-roof systems at a 10–15 degree tilt generally live comfortably inside this.
• Ground-mounted (stand-alone) arrays stay tightly limited. Under Class B, a garden array is capped at 9 square metres of panel area as standing permitted development, with height and siting conditions on top. Anything larger — which includes most paddock-scale systems — needs a planning application. Our ground-mounted installation guide covers when a ground array is the right answer despite the planning step.
• Listed buildings still need consent. Permitted development rights for solar do not apply within the curtilage of a listed building, and listed building consent is a separate regime again. No 2026 change touches this.
• Conservation areas still restrict some elevations. Wall-mounted installations visible from a highway remain constrained in conservation areas and World Heritage Sites — the exact position depends on the elevation and the designation, and this is precisely the situation where a written check with the local planning authority before survey is worth the week it takes. An in-roof (integrated) system fitted at re-roof time is often the design answer a conservation officer will accept — see our in-roof installation guide.
• The long-standing “minimise impact” conditions remain part of the regime — equipment sited, so far as practicable, to minimise its effect on the building’s external appearance, and removed when no longer needed.

Permitted development is not the whole rulebook

A point that catches buyers out every year: planning permission is only one of three consent regimes touching a solar installation, and the August 2026 changes affect only that one.

Building Regulations still apply in full. The structural adequacy of the roof (Part A) and the electrical work (Part P — solar installation is notifiable electrical work under BS 7671) are untouched by the planning changes. A proper installer deals with both as standard; a survey that never looked at your rafters is a red flag regardless of what planning law allows. Our step-by-step installation guide shows what that survey and the install itself should look like.

The grid connection rules still apply in full. Whether your system falls under G98 (connect then notify) or G99 (approval before energisation) is a matter of inverter capacity, not planning — the general planning permission guidance on gov.uk will not tell you, and neither regime cares that your panels are permitted development.

So the honest summary for a homeowner: SI 2026/896 makes wall-mounted solar meaningfully easier and tidies the house/flat split, but nothing about it removes the need for a structural check, certified electrical work, or the right DNO paperwork in the right order.

What this means in practice, buyer by buyer

Typical house, typical pitched roof: nothing changes for you. Your on-roof array was permitted development before 27 August 2026 and still is, inside the same 0.2 metre roof-slope limit. The original Part 14 of the GPDO 2015 has carried this right since 2015, and the amendment does not disturb it.

Poor roof, good gable: you are the winner from this Order. A bracketed wall array projecting up to 0.4 metres is now permitted development on most houses, provided the wall does not front a highway. Worth pricing against a ground mount before assuming the garden is the only alternative.

Flat owner or block manager: read the flats-specific class before commissioning anything, and expect the position to be more conservative than the house rules now are.

Listed building or conservation area: the 2026 changes do not rescue you from consent. Budget the time for the application or the conservation-area check, and lean towards integrated designs that officers historically accept.

Anyone being told “the rules changed, so it’s fine now”: ask which class, which limit, and for the planning position in writing. An installer who confirms the planning position in writing at survey — the standard we would hold any firm to — will not mind being asked.

Quick answers on the 2026 planning changes

Do I need to do anything about panels installed before 27 August 2026? No. Systems lawfully installed under the previous permitted development rules remain lawful. The amendment changes what may be installed from that date forward; it does not reach backwards.

Does the 0.4 m allowance let me raise my roof panels higher off the tiles? No — this is the misreading covered above. The 0.4 metre figure is a wall projection allowance. Roof-mounted panels remain limited to 0.2 metres beyond the roof slope, which standard rail systems sit well inside anyway.

Do these rules apply in Scotland or Wales? No. SI 2026/896 amends the English GPDO only. Scotland and Wales have separate permitted development regimes with different limits, so cross-border reading of any English planning guide — this one included — will mislead you.

If you want the planning position for your specific house checked and put in writing as part of a survey, request a free quote — or browse the FAQs for the wider set of installation questions this blog covers in depth.