In brief
Ask for the MCS certificate, the G98 or G99 paperwork, the electrical certificate and every warranty, and find out whether the panels are owned or sit on a leased roof. Under the SEG scheme, export payments do not pass with the house; you set up your own. On a listed railway cottage, ask what consent was granted.
First questions, before you make an offer
Three questions decide most of what follows. Does the seller own the panels outright, or are they owned by someone else under a lease of the roof? When were they installed, and by which firm? And is there a pack of documents to go with them? Ask through the estate agent early, because the answers affect your solicitor’s work and, in the case of a leased roof, possibly your mortgage.
The property information form a seller completes for the conveyancing usually asks about solar panels, so the answers should appear in writing. Do not rely on the listing alone; “solar panels” in an advert says nothing about ownership, condition or paperwork.
The MCS certificate
A system installed by a firm certified under MCS receives a certificate recording the installation, its size and the firm that fitted it. It matters for two reasons. An export tariff under the SEG scheme requires it, and it shows the system was fitted by a certified firm to the scheme’s standards. If the seller cannot find it, ask them to obtain a copy before completion; the firm that fitted it can be looked up on the MCS register.
Grid paperwork: G98 or G99
Every grid-connected system should have been notified to, or approved by, the local network operator. Smaller systems are notified under G98 after installation; larger ones, or those with a battery taking them over the limit, need G99 approval beforehand. Ask for a copy of whichever applies. If a battery or extra panels were added later, ask whether the paperwork was updated. You can identify the operator for the address through the ENA postcode search, and grid connection in Crewe explains both routes.
Electrical certificates and building regulations
The electrical work should come with an electrical installation certificate, and the installation should have been notified under building regulations, usually through the firm’s membership of a competent person scheme. Ask for evidence of both. A missing certificate does not necessarily mean the work was poor, but it is a gap your conveyancer will want closed, and closing it after completion is harder.
Export payments after you move in
Under the SEG scheme, the seller’s export tariff is their own contract with their supplier, and it ends when they leave. After moving in, you choose an export tariff for yourself. You will need the MCS certificate and a meter that records exports, usually a smart meter. Rates and conditions vary between suppliers, and some tariffs are only for the supplier’s own import customers. The monthly pattern of output and how much a household tends to export are explained on export and self-use.
Some older systems are paid under the Feed-in Tariff, an earlier scheme that works differently. If the seller receives payments of that kind, ask who pays them and how the change of owner is handled, and get the answer in writing.
Warranties
A solar system usually carries several separate warranties: one from the panel maker covering the product and its performance over time, one from the inverter maker, one for any battery, and the installing firm’s workmanship warranty. Ask for all of them and check whether each transfers to a new owner automatically or needs registering. Inverters typically have a shorter life than panels, so note when the inverter was fitted and whether it has already been replaced.
The workmanship warranty is only as good as the firm behind it. Ask whether it is backed by insurance that would pay out if the firm stopped trading; consumer codes such as RECC and HIES have rules on this, so ask which code the firm belonged to. The checks on firms themselves are on choosing an installer.
Leased roofs, in general terms
Some homes have panels that the homeowner does not own. Under these arrangements a company installed the system, owns it and receives any payments linked to it, while the household uses the electricity it makes during the day. The company holds a lease of the roof space, often for a long term. That lease binds whoever owns the house.
A leased roof is not automatically a problem, but it needs careful reading. Your conveyancer will want to know how long the lease has to run, what happens if the roof needs repairs, whether the company must consent to a sale or to works, and whether the lender accepts the arrangement. Some lenders have conditions about these leases. Do not exchange until those questions have clear answers.
Listed railway cottages: ask what consent was granted
Historic England lists 29 railway-company cottages in central Crewe at Grade II, in three terraces: Betley Street, Tollitt Street and Dorfold Street. A listed building cannot take panels without both planning permission and Listed Building Consent. If you are buying one of these cottages, or any other listed building, and it has panels, ask for both documents. If they cannot be produced, raise it with your conveyancer and the council before exchange: unauthorised work to a listed building can become the new owner’s problem. The National Heritage List shows whether any other building is listed, and the railway cottages page covers these terraces in detail.
For an unlisted house, panels within the permitted development limits needed no application. The rules, including the 2026 amendment, are on planning rules for Crewe.
Buying a flat with panels on the block
Panels on a block of flats usually belong to the building owner and feed the landlord’s supply. Ask who owns and maintains them, whether their running and replacement costs fall within the service charge, and whether the lease says anything about them. If panels feed the flat you are buying directly, treat them as you would on a house and ask for the full paperwork. Flats and solar covers how blocks are wired.
Buying to let
If you are buying a home to let and it has panels, decide in advance who will hold the export tariff and how the electricity used during the day will benefit the tenant. Landlords have their own considerations, set out on landlords and solar.
Is the system working?
Ask the seller for generation readings, ideally a full year, month by month, from the inverter display or its app. For comparison, PVGIS 5.3 models roughly 951 kWh a year from each kWp on a south-facing 35° roof near Crewe, and about 761 on an east-facing one; multiply by the system size to get a rough yearly figure, and see output on a Crewe roof for other directions. A shortfall is not proof of a fault, because shading and pitch matter, but a large one is worth asking about. Look at the inverter for warning lights, and if there is a battery, ask how old it is; batteries in Crewe covers what to look for.
A buyer’s checklist
- Owned outright or on a leased roof?
- MCS certificate and electrical installation certificate.
- G98 notification or G99 approval, updated for any later battery.
- All warranties, and whether each transfers.
- Recent generation readings and any repair history.
- For a listed building: planning permission and Listed Building Consent.
A question about a particular property can go through the question form.