The Best Roof Types for Solar Panels in the UK Explained

For UK homeowners looking to cut energy bills and their impact on the planet, putting in solar panels is a really good idea. But not every roof is born equal when it comes to having solar (photovoltaic) technology on it. Knowing what makes a great solar roof for a British property will help you work out if your house will be suitable, what problems you might run into, and how to get the most power from it over the long haul.

This guide will explain the different types of roofs you’ll find around Britain, how well they work with solar panels, and the things all homeowners should think about before getting a system.

What Makes a Roof Good for Solar Panels?

A few things decide how well your roof will work with solar. Before we look at specific roof materials, let’s think about these basic points.

Which way the roof faces & its 'aspect'

In the part of the world we live in (the northern hemisphere), south-facing roofs get the most direct sunshine during the day, and so are best for making solar power. East-facing roofs pick up the good morning sun, while west-facing ones benefit from the afternoon light. North-facing roofs are the trickiest, though even with those, modern panels can still make electricity from the daylight that's around.

Your solar company will look at the direction your roof faces using pictures from satellites and maps to guess how much power it'll make each year. And even if your roof doesn't face exactly due south, a well-planned system can still save you a lot of money.

How steep the roof is (pitch and angle)

For solar panels in the UK, the best angle is between 30 and 40 degrees from flat. Luckily, most British roofs with a slope are naturally in this range, which makes putting the panels up easier. If your roof is flatter or steeper, you can use mounting gear to change the angle of the panels to catch more sun. Flat roofs need special equipment to tilt the panels towards the sun, usually with heavy frames that don't poke holes in the waterproof layer.

How strong the roof is

Solar panels add about 15 to 20 kilograms for every square metre they're on, and that's including the things you use to attach them (brackets and rails). Most houses built after the war have roofs that can handle this weight easily. But older Victorian terraces and cottages might need a structural engineer to check. And importantly, your roof should have at least another 20 to 25 years left in it, because taking the panels off to fix or replace the roof later will be expensive and a pain.

How much space is actually free on the roof?

A typical 4kW system for a house needs around 20 to 25 square metres of roof space that you can actually use. You have to think about chimneys, dormer windows, pipes sticking up, and whether trees or other buildings will cast shadows on the roof. Even a roof that's technically good for solar won't work well if it's in shade for a lot of the day when the sun is at its strongest.

What About Different Types of Roofs You Get in the UK?

Different roofing materials work with solar panel mounting systems to different degrees. Here’s a look at how the most common British roofs compare.

Concrete and Clay Tiled Roofs

Concrete and clay tiles are what most solar installers in the UK come across, and generally they are great for photovoltaic systems. They last a long time, can withstand the weather, and you can attach standard brackets to the wooden supports (rafters) under the tiles.

You carefully lift the tiles to screw in the brackets, then put the tiles back and make sure the area around the hole is waterproof. Concrete tiles are the easiest to work with because they’re all the same size and very strong. Clay tiles are more delicate and can crack when you lift them, but experienced fitters have special tools to reduce this risk.

Sloping tiled roofs naturally drain water, so snow and leaves slide off the panels in winter. Also, the usual angle of a tiled roof often matches the best angle for getting the most from the sun, so you don't need complicated mounting.

Natural Slate Roofs

Slate roofs (common in Wales, the Lake District and on Victorian houses all over the UK) are more difficult for solar installations. Slate is brittle and can break if you walk on it or press it too hard when you’re fitting things.

With slate, you have to take sections of the roof off to get to the rafters to attach the brackets, then carefully cut and replace the slate around the fitting. They make special flashing kits for slate roofs to make sure there are no leaks around the bracket holes.

If your house is listed or in a protected area, there may be even more rules about changing the slate roof. Always ask your local council planning department before doing anything to a slate roof on a building of special historical or architectural importance; you might need Listed Building Consent.

Flat Roofs

Flat roofs are becoming more common on new extensions and new-builds and can be very suitable for solar panels, as long as they’re checked properly. Unlike sloping roofs, you need angled mounting systems to tilt the panels towards the sun - usually at 20 to t30 degrees.

The good things about putting panels on a flat roof are that you can decide which way to face them, without having to worry about the direction the building is facing, and they're less visible from the street, which can be a plus if you're in a nice area. Ballasted mounting systems (using heavy frames instead of going through the roof) don't damage the waterproofing and are often the best choice for felt or membrane flat roofs.

However, you need to do careful calculations to make sure the wind doesn't lift the panels off. Because the panels stick up, the wind can get under them and lift them up. You have to use enough weight to stop this. The installer will work out how much weight you need depending on how tall your building is, where you are, and how strong the wind gets. Also, flat roofs can be more easily shaded by walls around the edge or nearby buildings.

Metal Standing Seam Roofs

Standing seam metal roofs (popular on modern self-builds, converted barns and farm buildings turned into houses) are one of the easiest to put solar panels on. The raised strips that run down the roof give you a place to attach special clips that hold the metal without making any holes.

Because you don't have to make holes, you don't risk leaks and you don't invalidate the roof manufacturer's guarantee. Metal roofs generally last longer than the solar panels on them - so you'll never need to take the panels off when it’s time for a new roof. Their smooth surface helps snow and bits of rubbish slide right off, keeping the system working at its best all year.

*Corrugated and Profiled Metal Roofs

The sort of corrugated or gently sloping metal roofs you see on factories and some country houses need a different way of fixing the panels than the ‘standing seam’ type. Usually, rails that go over several of the roof’s waves are used, and they’re screwed into the roof and the supports underneath with self-drilling screws.

These can be done, but you have to be really careful to keep the water out with special rubber seals and flashing. Because a lot of corrugated roofs are from factories, it's extra important to check how much weight the roof can take, as the supports and how sturdy the roof is will vary a lot. Make absolutely certain your installer has worked on your type of roof before.

Thatched Roofs

Thatched roofs are by far the trickiest for solar panels and need very specific solutions. Thatch catches fire, so fire rules are strict about anything electrical, and that means you must have fire breaks and plenty of space around the wires.

You can't just attach standard brackets to thatch. Instead, special frames spread the weight of the panels to the building’s walls or wooden frame, going over the thatch without pressing down on it. These are complicated, expensive, and each one has to be designed specifically for the house.

People with thatch often find it much easier to put the solar panels in the garden, as long as there's enough space that isn't shaded and you get permission from the council.

Before You Fit – What About the Structure?

Whatever your roof is made of, there are a few things about its construction you need to think about before you start.

Roof Age and Condition

Before you put panels up, look closely for tiles that have slipped, slates that are cracked, flashing that's falling apart or wood that's rotting. Sort out any leaks or weaknesses first. A good installer will give the roof a very careful inspection and might suggest repairs or strengthening before they put the panels on.

If you're going to need a new roof in the next ten years, get the roof done first. Taking the solar panels off and putting them back on later will cost you a lot of money and could break the panels or the roof.

Shading

Trees nearby, next door's buildings, chimneys, even phone wires can cause shadows that really cut down how much electricity the panels make. Some newer solar systems have ‘optimisers’ or ‘micro-inverters’ that lessen the impact of shading on each panel, but it’s still best to avoid shade completely.

Ask your installer for a thorough shading study. They’ll use computer modelling to work out how nearby things will affect how much power you’ll get throughout the year. South-facing roofs that are only shaded in the early morning or late evening usually do really well.

Planning and Building Regulations

Most solar installations in England and Wales don't need official planning permission, as long as the panels don't stick out more than 200 millimetres past the edge of the roof. However, ‘listed’ buildings, properties in conservation areas and flat roofs that are too high are exceptions.

You do need building regulation approval for the electrical and structural work. Your installer should be on a list of approved people (like NICEIC or ELECSA) so they can say themselves that the work meets British Standards. You’ll need this certificate when you sell your house, as the buyer's solicitor will want to be sure the electrical work is safe.

The rules are a little different in Scotland and Northern Ireland. Always check with your local council before you start.

What Will It Cost?

How good your roof is directly impacts how cost-effective solar is. The best roof for solar panels for a UK house will take a bigger system that makes more electricity for you to use and to sell back to the National Grid.

The Smart Export Guarantee means energy companies have to pay you for any extra electricity you send to the Grid. South-facing roofs that can hold 16 to 20 panels can make a good amount of extra electricity in the summer, and this makes a better return on your money than smaller systems that are shaded or face north.

More unusual roof shapes that need special mounting systems, special frames to weigh the panels down, or careful work to protect old buildings will all add to the price. Get lots of quotes from installers who are registered with MCS and can look at the details of your roof, the shading, and how strong it is. The cheapest quote doesn't necessarily mean it’s the cheapest overall - it might not include the cost of doing the job safely and correctly for your roof.

Looking After Your Panels and How Long They’ll Last

Once they're up, solar panels don't need much looking after, but you need to be able to get onto the roof. Sloping roofs with a good ladder point allow for occasional cleaning and a check-up each year. Flat roofs are easier to get onto for maintenance, but you need to have a safe way to do so.

Make sure your installation has a monitoring system that will tell you if the electricity production goes down, which could be because of shading, a broken inverter or something on the panels needing attention.

In Conclusion

Tiled, sloping roofs that face between south-east and south-west are generally the best option for most people in the UK who want solar panels. They’re the best combination of being strong enough, easy to fit and facing the right way - which is what makes them the best roof for solar panels for most UK houses.

But slate, flat and metal roofs can all have solar panels put on them if experienced fitters use the right fixing methods. Even tricky roofs like thatched ones can* have solar, though householders have to weigh up the higher costs and complexity against how much money they’ll save on energy.

Before you go ahead, get a detailed inspection of your roof from an MCS-approved installer. They'll look at how strong it is, how long it has left, how much shade it gets and how big the system should be. Sorting out any repairs or making it stronger first will make sure your solar panels work reliably for as long as the guarantee says they will, giving you energy independence, protecting you from increasing bills and cutting down on carbon emissions for many years.