An 800 W device on an ideal London roof makes 795 kWh a year, three kWh shy of the same device in Cardiff. What separates the two cities is not daylight. It is the number of people who get a say before anything is fixed to a wall.
Below are the five gates in the order we would test them. Each names who decides. Four of them can close. The fifth cannot, and it is the one most people worry about first.
This one is free and it takes a minute, which is why it goes first. The permitted development right for solar equipment was rewritten on 27 August 2026, the same day the product became lawful, and it does not stretch to plug-in solar fixed to a wooden wall, a balcony or timber cladding. The Planning Portal lists that prohibition for houses and for blocks of flats alike.
Almost every retailer in the country is selling these as balcony kits. If your balcony is timber or timber clad, that is the case the right leaves out, and a job that would have been a formality becomes an application to your borough.
Three more exclusions sit in the same right and London holds a lot of the buildings they catch. No panels on a wall fronting a highway in a conservation area or a World Heritage Site. Nothing in the grounds of a listed building or on a scheduled monument. A listed flat needs planning permission and listed building consent both, and the Planning Portal advises getting pre-application advice early.
A transitional year runs to 27 August 2027, in which either version of the right may be relied on. Anyone quoting you for work on a timber surface should be able to say which of the two they are working to, and when that stops being an option.
For most of London this is the gate that actually settles it. The government's own response to the consultation records respondents raising "the need for renters and leaseholders to seek landlord or freeholder consent", and warns that "leasehold restrictions, landlord consent requirements, planning barriers and wider building management considerations may limit uptake unless addressed alongside the framework".
SI 2026/848 is product safety and electricity supply law. It changed what may be sold and plugged in. It did not rewrite anybody's lease, and the department that drafted it treats consent as a barrier still standing.
A freeholder saying yes and a managing agent saying yes are not always the same event, and we cannot read your lease from here. What we can do is tell you which questions get a usable answer, and that list is on the flats and freeholders page.
The last gate is the only one where nobody has to agree to anything. Connection in Great Britain runs under Engineering Recommendation G98, and for a device this small the consumer step described by the department is a short online form after the fact, not an application before it.
Our working map puts London in the licence area of London Power Networks plc, part of UK Power Networks. Put your postcode through their checker before you write to anybody: what we hold is a map of licence areas, not a verified fact about your street.
A Londoner who cannot face any of that can dial 105 for nothing and be put straight through to the company that owns their cable.
Four mountings at one point in central London, queried from PVGIS on 13 September 2026. Read across rather than down: where a panel points changes the answer more than which city it is in.
| Where the panel ends up | Output a year | Share of the best case |
|---|---|---|
| Pitched roof facing south, 35 degrees | 795 kWh | 100% |
| Free-standing frame in a garden, 30 degrees | 789 kWh | 99% |
| Flat against a south-facing wall | 582 kWh | 73% |
| Flat against an east-facing wall | 409 kWh | 51% |
A free-standing frame at 30 degrees lands within one per cent of a perfect roof pitch, and it is the one arrangement the rewritten planning right has no quarrel with. If you have any ground at all, a communal courtyard included, that is the option to put to your freeholder.
They assume nothing shades the panel, which in a terraced street is optimistic. They come from one point, not from your postcode. Generating is not saving, and since batteries sit outside the approved class there is nothing to do with the surplus but export it unpaid. And an east wall at 409 kWh is barely half a roof, which is worth knowing before you spend anything.
Five questions, and the ones that matter in London are the last three.
Send a postcode, what sort of building it is and how you hold it. We reply with the licence area we believe covers you and how to confirm it, the generation figures run at your own location instead of a city centre point, and a plain reading of which of the five gates are likely to be yours.
We are not installers and we are not a retailer. If the honest answer is that your building will not allow it, you will get that answer.