Plug-in solar for flats and apartments

Flats and apartments are exactly where plug-in solar is most interesting in principle, and most constrained in practice. A full rooftop installation is usually out of the question — the roof is shared, out of reach, or both — so a small, movable system is often the only realistic way to generate any of your own electricity.

Before going further, the essential caveat: in the UK, plug-in solar cannot currently be legally sold, supplied or used. A Government consultation that could change this is open until 30 June 2026. This guide is here so you can plan sensibly, not so you can buy a system to use today. The detail is on the UK legal status page.

The challenge with flats

The defining feature of a flat is limited or no roof access. The roof is typically a shared part of the building that individual residents have no right to use, and even where access exists, fixing a panel to a communal roof would usually need the agreement of the freeholder or managing agent. That pushes any small system down to the spaces you do control or have a clear right to use.

That is not as limiting as it sounds. Plug-in solar is small by design and aimed at offsetting everyday background electricity — the fridge, router and devices on standby — rather than running a whole home. A single well-placed panel can make a meaningful dent in that background load, so the question is less “is there a roof?” and more “is there a sunny spot I am allowed to use?”

Where panels can realistically go

In a flat, there are three places a small system can usually live. None matches a rooftop array, but each can be worthwhile if it faces a decent direction and is not heavily shaded.

• A balcony. For most flats this is the best option. A panel can hang on the railing or fix to the balcony wall, with a lead running back inside. Our balcony guide covers railing versus wall mounting, orientation and the safety points in detail.
• An external wall. Where you have the right to use a stretch of outside wall — for example on a ground-floor flat with a private patio — a wall-mounted panel, sometimes on an angled frame, can give a more secure and weatherproof result than a railing.
• A window or window box. With no balcony or usable wall, a sunny window is the fallback. A panel sat on a sill or in a window box, or fixed to the reveal, collects less than an outdoor mount and a pane of glass reduces the light reaching it, but a south-facing window can still be useful.

Orientation and tilt drive how much each option produces. South gives the most generation in the UK, with east or west giving less but still useful output, and a vertical surface collects less than a tilted one. To see what a particular spot might produce, use our output calculator, which is built on PVGIS data.

Shared buildings, leaseholders and freeholders

The biggest difference between a flat and a house is that much of the building is shared. That changes who has a say over anything fixed to it.

• If you hold a leasehold, your lease sets out what you can and cannot alter, and the freeholder typically owns the structure and exterior. Fixing a panel to an outside wall or a shared balcony may need their consent.
• If you rent, your tenancy agreement may restrict fixing items outside or making alterations, and your landlord may in turn need the freeholder's agreement.
• Where a managing agent or residents' association looks after the building, they may need to agree anything that affects its appearance, structure or communal areas.

Permissions to check first

Because so much of a flat is shared, permission is more likely to come into play than for a private house, and it is worth sorting out before anything is fixed. Check your lease or tenancy for restrictions on external fixings and alterations, identify who owns and manages the part of the building you want to use, and ask for any consent in writing so everyone is clear.

Our guide to landlord and freeholder permission explains what to ask and how to put it in writing, and our planning permission guide covers the situations that need more care.

Making the most of a small space

A flat rarely offers room for more than one or two panels, so the value comes from placing what you can fit as well as possible and using the electricity as it is generated. Pick the sunniest spot you are allowed to use, give the panel the best angle the location permits, and watch how shade from neighbouring buildings, the balcony above or nearby trees tracks across it through the day. Then aim to run flexible daytime loads — charging, laundry, the dishwasher — while the sun is on the panel, since only the electricity you use as it is generated reduces your bill.