The short answer
Usually it protects value and helps a sale more than it adds a set sum to the price. A worn roof is something a buyer's surveyor flags, and a new one removes that flag, which can make the house easier to sell and stop a buyer asking for money off. Treat any claim of a fixed percentage uplift with caution.
Why a new roof matters more to saleability than to the valuation, what buyers and surveyors notice, and which documents back it up.
Value or saleability?
People often ask what a new roof adds to a house, and the straight answer is that no one can give you a reliable sum. A roof is a basic part of the building, and buyers expect it to work, so they rarely pay extra for one that does. What they do is mark a house down when the roof looks tired. A new roof therefore tends to protect the asking price, not raise it by the cost of the work.
It also changes how a sale feels. A house with a sound, recent roof gives a surveyor less to write about and a buyer less to negotiate with. A house with an ageing roof can attract a lower offer, a request for money off, or a buyer who walks away when the survey arrives. Those are the practical gains, and they are real, even though they are hard to put a figure on.
If you are staying put, the gain is different: no leaks, no repeated repairs, and a roof you do not need to think about for a long time. Tile lifespans are quoted as ranges and never as promises, but they run to decades, and the gain lasts for as long as you stay. A sound roof also means you are not paying for repeated call-outs while you live there.
What buyers and surveyors look at
A buyer's surveyor will study the roof from the garden, from the loft hatch and sometimes with a camera on a pole. They note slipped or cracked tiles, sagging lines, moss, patched flashings and a worn ridge. Inside, they look for damp stains on the ceilings and on the roof timbers. A flagged item in a report gives the buyer a reason to push for money off, or for a repair, before exchange.
A new roof answers those points directly. You can show that the covering, battens and underlay are new, that the ridge and verge are fixed properly, and that the flashings were renewed. It also helps if the loft timbers are dry and the insulation is in good order, since a surveyor who finds a dry loft is less likely to dig further. The roof is one of the larger single items a buyer worries about, so removing the worry has a value of its own.
One caution: do not re-roof only to sell if a repair would do. Our page on roof replacement shows when patching beats replacing, and the survey decides which applies to your roof.
The paperwork that backs it up
A new roof helps most when you can prove it. File the written quote, then the final invoice, so the date and scope are on record. Keep dated photos from before, during and after the job, which reveal the timbers, underlay and fixings hidden once the covering goes on. Keep the product name and data sheet for the covering, and any warranty in writing from the maker or the roofer.
If the job needed building control approval, the completion certificate is the key document, and a buyer's solicitor will usually ask for it. The Planning Portal sets out when approval is needed, and your own council may word the rule differently. Our answer on whether you get a certificate for a new roof covers this in detail.
If the scaffold needed a licence for pavement space, file a copy of that too. Put everything in one folder, and hand it to your solicitor at the start of a sale instead of hunting for it later, when the buyer is waiting and the dates are tight. A calm, organised file reads well to a buyer, and it shows the roof was done as a planned job and not as a rushed fix.
Choosing the work so it counts
Value follows quality. A poor re-roof that fails within a few winters does nothing for a sale, so the specification matters. Ask for a named covering suited to your roof's pitch, new battens where the old ones are tired, a good underlay, and mechanically fixed ridge and verge. BS 5534 covers slating and tiling, although Marley says the code is not a legal requirement.
Match the look of the street too, because a covering that clashes with the neighbours can put buyers off. On a road of similar houses, a covering close to the original looks right, and in a conservation area the council may expect it. Our answer on re-roofing in a conservation area goes through the checks.
Compare written totals on the same scope, using our guide to comparing roof replacement quotes. If you are planning to sell, tell us your timescale and share a photo of the roof. We will explain which parts a buyer's surveyor is likely to question first, and what the written price would need to cover.
More on this in Roof Replacement & New Roofs in Crawley
Two selling questions
Will a new roof raise my valuation by the cost?
Do not expect that. A roof is an expected part of a house, so buyers rarely pay extra for a working one, but they do mark down a poor one. Treat any fixed percentage uplift with caution. Ask a local estate agent how roofs affect offers on your street.
Should I re-roof before selling or leave it to the buyer?
It depends on the roof. If it leaks or the survey will flag it, dealing with it first gives you control of the price and the paperwork. If the roof is sound and only older, a repair may be enough. A survey of your roof, with photos, shows which case you are in.