Plug-in Solar London

The surface decides it before anyone else does

A minute with a tape measure and an honest look at what your balcony is made of will settle more than a month of correspondence.

The exclusion the market has not caught up with

Search for these devices and you will be sold balcony solar. The phrase is on the packaging, in the product names and across the listings. Then read the right that came into force on 27 August 2026 and you find, for houses and for blocks of flats, a prohibition on wooden wall, balcony or timber-clad installation, annotated as applying to plug-in solar.

We have yet to see a retailer mention it. It does not make the product unlawful and it does not stop you applying to your borough in the ordinary way. What it removes is the assumption that no permission is needed, which is the entire convenience these kits are sold on.

What counts as timber is not obvious from a photograph

Plenty of London balconies are a steel or concrete frame with a timber-clad face. The cladding is the part the right names. If you are unsure what is behind yours, that is a question for the managing agent rather than a guess, and it is cheaper to ask than to fit.

The limits, side by side

Both columns are the rules as rewritten. Until 27 August 2027 a transitional period runs, and the Planning Portal says you may "follow the rules as they were immediately prior to 27th August, or the new rules".

ConditionA houseA block of flats
Pitched roofBelow the ridge, projecting no more than 200 mmBelow the ridge, projecting no more than 200 mm
Flat roofNo more than 600 mm above the roofNo more than 600 mm above the roof
Wall abutting a highwayUp to 200 mm projectionCovered by the conservation area and World Heritage Site restriction below
Other wallsUp to 400 mm projectionCovered by the same restriction
Wooden walls, balconies and timber claddingNot covered, plug-in solarNot covered, plug-in solar
Conservation area or World Heritage SiteNo panels on highway-fronting wallsNo panels on highway-fronting walls
Listed building grounds, scheduled monumentsExcludedExcluded

A listed building itself needs planning permission and listed building consent, and the Planning Portal recommends seeking pre-application advice early.

What that leaves a London flat

Working down from the exclusions rather than up from the marketing, four options survive in most blocks, in rough order of how well they perform.

A

A frame on any ground you can use

Within one per cent of an ideal roof, fixed to nothing, and the arrangement the right has least to say about. A communal courtyard needs the freeholder, but the planning question largely disappears.

789 kWh a year
B

A brick or rendered south wall

Roughly three quarters of the best case. Brick is not wood, so the timber exclusion does not reach it, though a highway-fronting wall in a conservation area still will.

582 kWh a year
C

A flat roof or roof terrace

Permitted up to 600 mm above the roof surface. In a block this is almost always common parts, which moves the decision to the freeholder before it reaches the council.

Within 600 mm of the roof
D

An east or west wall

About half a roof. Worth doing if the alternative is nothing, but go in knowing the figure rather than discovering it on a bill.

409 kWh a year
A metal or glass balcony is a different question from a timber one

The right names wooden walls, balconies and timber cladding. It does not name steel, glass or concrete. We are not going to tell you a steel balustrade is therefore permitted, because that is a reading of the order rather than something the Planning Portal states, and the order itself is one of the items we still have open. Ask your borough, and ask before you buy.