Plan a solar installation

The short version

Most of the work in a solar project happens before anyone climbs on your roof. First, you gather your bills, compare quotes, and settle the design. Then your installer handles the paperwork for the grid, and you sign up for an export tariff.

This page lays out the order of events. It also flags where rules differ across the UK, because they do. For the roof checks that come first, see roof and property suitability. For how the parts work together, see how domestic solar panels work.

Before you ask for quotes

Start with your own numbers. Collect twelve months of electricity bills if you can. Note your current tariff and your unit price. Work out when someone is home, because daytime use makes solar more valuable.

Then walk round the property, since shade is easy to miss. Take photos of the roof from the ground. Note trees, chimneys and tall neighbours that may cast shade. Write down what you want from the system, such as lower bills, a battery, or an electric car charger.

Next, decide how you will pay. For example, Energy Saving Trust says there are no dedicated UK Government grants for solar panels as of its latest update. Some schemes may include solar as part of a package, depending on where you live and whether you get benefits. Our guide to solar panel grants and funding explains what is on offer.

Comparing installers

Energy Saving Trust advises getting quotes from at least three installers. It also advises choosing installers certified by the Microgeneration Certification Scheme (MCS), because MCS is the government-backed quality scheme for small renewable systems. Our post on MCS certification explained covers what the mark does and does not promise.

Use the same questions for each installer, so you can compare like with like. However, do not rely on price alone. Energy Saving Trust suggests four good ones. What electricity price are you using to estimate savings? How much power will I use myself, and how much will I export? How are you allowing for shade and roof direction? What warranties come with the panels, the inverter and the work?

Record the answers in one table, since it makes gaps obvious. Include system size, named equipment, the estimated output, what is left out, the warranties and the total price. Our guide to choosing a solar installer goes through red flags and the certificates to ask for.

The survey and the design

Before the work, an assessor visits to check that the roof is safe to hold the panels. They also design the system around your roof and your use, while the final design is agreed with you. Some sites are assessed remotely. If so, MCS says the installer must tell you when real site factors may change the result.

MCS requires an output estimate before you sign. That estimate must follow the standard method, and it must carry a warning that it is not a guarantee. It should also include an estimate of how much power you will use yourself.

Ask to see the shade assumption, the roof tilt and the direction used. If a quote includes a battery, ask how it changes the numbers, because storage alters self-use. The post on east-west and flat roof solar shows how layout changes the design.

Planning permission and building rules

Most homes do not need a planning application, because panels are usually permitted development. But exceptions exist, so check before you sign. Our post on whether solar panels need planning permission covers each case.

In England, Planning Portal sets the limits. For example, panels on a pitched roof must not rise above the highest part of the roof, and must stick out no more than 200 mm. They cannot go on a building in the grounds of a listed building. Rules changed on 27 August 2026, with a transition period to 27 August 2027, so check the current page.

Wales and Scotland have their own rules, although they are similar in spirit. In Wales, the Welsh Government says most homes can have roof panels as permitted development, but listed buildings need consent. Scotland has its own permitted development classes. Northern Ireland differs too, so ask your council.

Building rules apply as well, since panels add load to the roof. In England and Wales, GOV.UK says a contractor in a competent person scheme can usually self-certify the work. Otherwise they must submit a building notice before they start. In Scotland, the local authority decides whether a building warrant is needed. The Welsh Government adds that the roof’s ability to carry the load must be checked and proven.

If you rent or own a leasehold flat, you may need permission from your landlord, freeholder or management company.

Grid connection and registration

Every system must be notified to your local network operator. Your installer normally does this for you, because they hold the right forms. GOV.UK says the notice covers solar, batteries, heat pumps and electric car chargers.

Small systems use the G98 route, which is connect and notify. For example, National Grid says the generation must be under 16 amps per phase and must shut down in a power cut. The installer must send the notice within 28 days of commissioning.

Larger systems use G99, so the installer must apply before the work starts. GOV.UK says the network operator should respond within 45 days for low-voltage devices. For a system with a battery, a fast-track form can cut this to 10 days or less.

Our post on connecting solar to the grid under G98 and G99 explains the forms. Ask your installer which route applies, and who sends the paperwork.

Installation day

Energy Saving Trust says an installer should take one to two days. First, the team puts up scaffolding, sometimes a few days before. Then they fix brackets to the roof and mount the panels. Finally, they connect the inverter to your home wiring and fit any battery or diverter.

Disruption is small, although the installer may switch your power off briefly to make the connection. Agree the timetable and the payment stages in writing first.

At the end, the installer tests the system and shows you how to check the output. They should also leave written advice on the checks you should make and what the fault signals mean.

Handover and what to keep

MCS requires a handover pack, so ask for it. It must include a signed declaration that the install meets the standard, a list of key parts, and the performance estimate. It must also name a recommended interval for the first inspection and give the MCS contact details.

MCS requires the installer to register the system and generate your MCS certificate within 10 working days of commissioning. Keep that certificate safe, because it is your proof of certification.

Also keep the warranty papers and the grid notice. Since checks matter, our maintenance and lifespan guide explains the checks to schedule after handover.

Selling your spare power

Once the system works, you can apply for an export tariff. In Great Britain, for example, the Smart Export Guarantee requires eligible suppliers to offer one. Ofgem says you can apply to any licensed supplier, not just your current one, and that suppliers set the rate and contract length.

Energy Saving Trust says you will usually need a smart meter and proof that the installation is certified. Compare offers before you sign, because rates vary. Our post on the Smart Export Guarantee explained shows what to compare. If you are adding a battery, our guide to solar batteries and export covers how storage changes the choice.

In Northern Ireland the Smart Export Guarantee does not apply, so Energy Saving Trust advises asking your energy supplier whether it offers an export tariff.