Solar panels on a garage roof: what to know before you start

Why a replacement is the best moment

You cannot fix panels to an asbestos cement roof: the fixings would disturb the sheets. Once the old roof is off and a new one is fitted, panels can be fixed to a sound structure with the scaffold already in place. The combined job is usually simpler and often cheaper than two separate ones.

What decides how much power you get

Orientation is the first thing. South facing is best, east and west work well too, and north facing is poor. After that, shade from trees, houses and chimneys and the pitch of the roof make the difference. A garage roof also holds fewer panels than a house, so total output is smaller.

Some owners use garage solar to cover daytime use and a battery for the evening, others export what they do not use. An installer can model it from a few photos and your electricity bill.

Batteries and wiring

Garages are a common home for a battery and inverter on a wall. Installers choose a spot that avoids water and vehicle impact. The connection between the garage and the house has to be done by a qualified electrician and follow regulations.

Costs and rules

Typical UK domestic solar systems are often quoted around £4,000 to £8,000, with batteries adding more. Rooftop solar on an existing building often does not need planning permission, but exceptions apply, including listed buildings and conservation areas.

Choose an installer registered with a recognised scheme and ask for itemised prices.