Buying a house with solar panels? These are the extra checks you need to make

Buying a house with solar panels can be tempting. After all, with the panels already in place, you don’t have to go to the trouble of having them fitted and you can take advantage of their benefits right away.

But it’s important to assess existing solar panels carefully when you’re buying a house, and consider any downsides, too. Age, condition, maintenance needs and more are important and, if you’re buying with a mortgage, solar panels can complicate matters.

To help you consider a house with solar panels when you’re buying we’ve put together an expert guide with all the details you need.

Buying a house with solar panels: Pros and cons

There could be benefits to a house with solar panels. “Buying a home with solar panels already installed will save you the hassle of getting it done yourself and should help to keep your energy bills reasonable,” says Thomas Goodman, construction expert at MyJobQuote. “You’ll also be spared the upfront installation costs, which can be between £6,000 and £7,500 for a 4kW system.”

On the downside might be their age. “Panels tend to last for at least 20 years, so if they’ve been put in fairly recently, you won’t need to worry about upgrades or replacements for a long time,” says Thomas. “Inverters, on the other hand, don’t tend to last so long. A string inverter typically lasts between 10 and 15 years. So, you may need to budget to replace this at some point.”

Equally, they may not be the type of solar panel you would choose. “Solar thermal is not really a compelling product any more, and if you did want solar PV then you might have to decommission the solar thermal, which has a cost (though take care if the install benefits from the renewable heat incentive),” says Simon Bones, CEO of Genous.

Nor might they have a solar battery. “You can add battery storage to an existing system, so it’s not a problem if the home you’re buying doesn’t already have this set up,” notes Thomas. “However, it will cost from around £2,500 to get this done.”

You might have to pay a premium for a house with solar panels. “Sellers may ask a higher price for a property to which they’ve fitted solar panels in an effort to recoup their costs,” says Phil Spencer, property expert and founder of Move iQ

“Estimates vary of how big this ‘panel premium’ might be in practice,” he adds. “Research by the trade body Solar Energy UK suggested that panels can add around 2 per cent to the value of a property. But some buyers are put off by the appearance of panels, meaning homes fitted with panels can appeal to a smaller pool of buyers, giving you greater leverage when it comes to negotiating on price.”

When you’re considering a home, it’s therefore crucial to assess the panels along with the house, and the details on what you should ascertain are below.

Thomas Goodman

Thomas Goodman has worked in the construction industry for over 20 years. Thomas continues to work on building projects, while also providing expert construction and property advice to industry professionals and DIY enthusiasts via the MyJobQuote platform.

Simon Bones

Simon Bones is chief executive and founder of Genous, through which he helps homeowners install solar, batteries and ancillaries (EV chargers, hot water power diverters, grid back-up) either on their own or as part of whole-home retrofits, which often also include insulation, glazing, heat pumps and smart energy technologies.

Phil Spencer

Phil Spencer is a presenter, author, businessman and property investor. As co-presenter of the long-running Channel 4 series Location Location Location, he has become one of the best-known faces on British television and is widely regarded as an expert on all things property. Outside of television, he has published three books and founded the property advice site Move iQ.

What to look for when you’re viewing a house

You should make a visual inspection of the panels as part of viewing a house, but stay on the ground for safety, advises Griff Thomas, MD for renewables training provider GTEC.

“Check for dirt, debris and other wear and tear,” he says. “Solar panels don’t usually need to be cleaned as they have a hydrophobic surface which prevents water droplets from sticking – as this water falls off it takes dirt with it – however, they may need cleaning after a particularly dry spell/if the house is in a sandy area (by the beach, for example), there’s a lot of tree pollen or visiting birds!

“Look over wiring connections to check they’re secure and undamaged,” he adds. ‘If the seller has a battery, check this too.

“Check for shading on the panels, such as trees,” he adds. “This will affect their performance. A well-designed system should’ve taken shading into account, but a branch might have grown since the panels were installed so removing any shading you can is something to consider if you buy the property.”

Griff Thomas

Griff Thomas is MD for renewables training provider GTEC, which delivers courses for heat pumps, solar, battery storage, electric vehicle charging and supports energy efficiency measures at locations throughout the UK. Griff has overseen the development of most of the national renewable technology standards.

Find out if panels are leased or owned

A vital factor when considering the purchase of a home with solar panels is whether they are leased or owned. “Rent-a-roof schemes used to be commonplace,” says Thomas Goodman. “These are essentially lease agreements where the homeowner gets to enjoy the energy produced by the panels but doesn’t necessarily own them. Plus, the money earned from sending surplus energy to the National Grid usually goes to the leasing company, rather than you. This type of lease is attached to the house, not the person who took it out.”

Whether panels are leased or owned can also affect borrowing. “Most mortgage lenders are happy to lend on homes fitted with panels that are owned outright by the property, and some even offer incentives that reward buyers who choose energy-efficient homes,” says Phil Spencer.

“However, things are trickier where the panels are leased rather than owned. Some lenders won’t offer mortgages to properties with leased panels, and those who do often have strict criteria. If you’re planning to buy a home fitted with solar panels, you really should enlist the help of a qualified mortgage broker to navigate these complexities and find the right lender for you,” Phil recommends.

Check solar panel installation documents

It’s important to check documentation for the panels. “Older solar PV installs may benefit from the feed in tariffs (FiTs), which means the owner gets paid for electricity generated and exported,” says Griff Thomas. “While FiTs ended in 2019, the scheme lasts until the end of the customer’s tariff, usually around 20 years from the point of install. You will need the FiTs transferred into your name if you buy the property.

“Newer installs (post 2019) that have been installed under the microgeneration certification scheme (MCS) benefit from the smart export guarantee (SEG), where money is paid by the energy provider for exported electricity,” he continues. “This would also need to be transferred on purchase of the property.”

You should ask to see the MCS certificate. “This will ensure the solar PV system has been installed to industry standards and is eligible for the SEG,” says Griff. “MCS provides consumer protection should something go wrong that was caused by poor installation.

“The solar system should also have an electrical safety certificate, a warranty and/or guarantee,” says Griff. “Solar PV often has long warranties of up to 30 years.”

You should ask to look at maintenance logs, too. “It’s also wise to check if the installer is still in business and establish contact with them,” says Jack Rable, technical director, Bublshop. “This ensures you have a reliable point of communication should warranties or maintenance be required in the future.”

Jack Rable

Jack Rable is technical director at Bublshop, suppliers of renewable equipment across the UK. Jack has worked there for six years, and provides support to homeowners and engineers.

Get a survey of solar panels

While you can make a visual inspection, it’s important to get the solar panels checked by a surveyor before purchasing a property, says Michael Zucker, surveyor at estate agency Jeremy Leaf & Co.

“It’s worth paying for a specialist rather than relying on a general survey,” he says. “The surveyor will need to look carefully into the type of equipment and whether it has been installed properly. Solar panels are still relatively new in the scheme of things so installers haven't always had time to establish a good reputation or track record.”

Michael Zucker

Michael Zucker is a surveyor at estate agency Jeremy Leaf & Co. He graduated in architecture before qualifying as a chartered surveyor. He joined Jeremy Leaf & Co in 1986, subsequently becoming a fellow of the RICS. Michael specialises in valuations for various purposes, in particular for leasehold enfranchisement.

Assess energy savings and maintenance costs

To assess solar panels, ask to see electricity bills to find out how much is generated and how much you could save. Keep in mind that age matters. “Older solar panels aren’t as efficient as newer panels and panels do degrade over time – typically their energy production drops by around 0.5 per cent every year that they’re in use,” says Thomas Goodman.

Think costs, too. Cleaning may be necessary from time to time and servicing according to the warranty.

Make an offer on a house with solar panels

If you decide to make an offer on a house with solar panels, consider whether they’re going to bring costs based on the type, age and maintenance, or whether they might result in small savings on your bills or larger ones.

“In terms of establishing whether there is a cost saving, the longer the panels have been in place the better as it will be easier to tell if there are genuine savings to be made,” says Michael Zucker.

Factor future bills into your offer, too. “If energy costs continue to rise, the argument for solar panels will undoubtedly be more compelling,” Michael says.

If you put in an offer on a home with solar panels, as well as other details your conveyancer will need to check for building regulations approval and planning permission if the installation did not fall under permitted development.