The specification is unusually clear about this, which is helpful, because a lot of people are guessing.
Connect a compliant device to a sound existing socket. The specification is written for devices "intended for installation and operation by ordinary persons". No electrician, no competent person scheme, no certificate.
That is the whole point of the product, and for a household with a suitable socket already in the right place, there is genuinely nothing to pay anyone for.
Anything that touches the building's electrical installation. The maker has to tell you in the instructions that testing or altering the installation belongs to a professional electrician working to the distribution code, G98 and BS 7671.
Replacing the overcurrent protection device on the final circuit is the example given, at BS 7671 Section 551.7.2, and it is named as electrician-only work.
You are also told to have an electrician inspect any socket whose condition or suitability you doubt, and not to connect to damaged, degraded or non-compliant sockets at all.
A surface the permitted development right does not cover.
The rules updated on 27 August 2026 exclude plug-in solar on wooden walls, balconies and timber cladding, for houses and for blocks of flats alike. An electrician cannot make that lawful. Only a planning application can, and for a device at this price that rarely makes sense.
A frame in the garden avoids the problem entirely, and at about 30 degrees facing south it produces within a per cent or so of what an ideal pitched roof would. It is usually the best available spot as well as the simplest.
Four questions, and it stops early if you cannot proceed.