The short answer
Possibly, but do not assume you can. A listed building is a matter for the council, which decides whether a change of slate needs listed building consent. Going ahead without it breaks the law. A conservation area adds a second concern, which is how the roof looks from the pavement. Ask B&NES planning first, and get the answer in writing before ordering slate.
Why the question arises in Bath
Welsh slate and Spanish slate look similar from a distance, and Spanish slate is cheaper. In MyBuilder's 2026 guide, installed Welsh slate costs £140 to £180 a square metre against £100 to £130 for Spanish, a gap large enough to tempt an owner re-roofing a terrace or a villa. Those are national averages from a cost guide, not an Empire quote.
But Bath is not an ordinary place to change a roof. The whole city is a World Heritage Site, and the city-wide conservation area covers about half of it. Bath also holds around 5,000 listed buildings. Slate is a large part of the city's roofscape, so a council officer may well care which slate goes on.
So the answer depends on the status of your building, not on the slate alone.
When the house is listed
B&NES tells owners to raise any listed-building work with the planning authority first. Consent for a listed building is not the same permission as planning permission, it notes, and proceeding without it is an offence.
That is strong wording, and it should govern your approach. Re-covering a listed roof touches the historic fabric of the building, and the council decides whether like-for-like repair is acceptable or whether a change of material needs formal consent. A different slate source can alter colour, texture and thickness, so it falls into the area where you ask rather than assume.
The council publishes its guidance at bathnes.gov.uk. The conservation team's number is 01225 394041 (Tuesdays and Thursdays), and its email address is conservation_andplanning@bathnes.gov.uk. Our page on listed slate roofs goes through the process in more detail.
Unlisted, but inside the conservation area
Conservation area status works differently. There, the council cares about the character of the area, and roofs are part of the street scene. Whether a change of slate source needs any application depends on the property, the nature of the work and any local controls, such as an Article 4 direction. Some streets are covered by Article 4 directions, which the council uses to remove certain permitted development rights in special areas, the Bath World Heritage Site among them. Roofs do not appear in its list of examples, which runs from porches and windows to doors, paint and sheds. Look at the council's policy map for your own street all the same.
We are not in a position to give legal advice, and it would be wrong to say that re-roofing in Bath always needs permission. It would be equally wrong to say it never does. The safe course is to ask, describe the slate you propose, and keep the reply.
The council's view, when it gives one, is usually practical. It will want to know the product, the size, the colour and how it will look beside neighbouring roofs.
What the council has said in practice
No published B&NES guidance on listed-building roofs has come to our attention, which leaves casework as the best evidence. The comments Bath Preservation Trust makes on individual applications show which way opinion leans.
Bath Preservation Trust commented on work to a Grade I house, 33 St James's Square, and described the pitched roofs as Welsh natural slate for the most part, with some clay pantiles at the rear. Among the works it supported were fresh leadwork in the valleys and getting rid of the asbestos slates. For the terrace at Lambridge Place, whose mansard roof and dormers are very visible, it favoured swapping the artificial slate for natural Welsh slate. These are examples, not rules, but they show that natural Welsh slate is the benchmark on significant Bath roofs, and that a downgrade is more likely to meet resistance than an upgrade.
A mansard has two pitches on each side, the lower one very steep, and in Bath it can stand out clearly from the street. The more visible the roof, the more the choice of slate matters.
Matching, sourcing and doing it properly
Even where no consent is needed, matching matters. Slates differ in colour, in how they weather and in thickness, and thickness changes the look of the roof along the eaves and ridge. Reclaimed slate is another route to a good match, and our page on reclaimed slate covers it.
Sourcing is not the only point. Approval and a structural check also follow if the new covering is 15 per cent heavier or more. Approval is not normally needed for small jobs, those affecting under 25 per cent of the building envelope and under 50 per cent of the roof. We explain these limits and handle the building control side where work is notifiable.
Matching the existing roof is our starting point. At the survey we identify the slate already there, photograph it, and tell you whether a substitute would stand up to a close look from the street. The fixed price that follows is in writing. The broader picture is on our slate roofing service page.
Steps to take before you commit
Start by finding out whether your house is listed, using the Historic England list or the council's records, and whether it sits in the conservation area. Take close-up photographs of the existing slate, and some from the street.
Then write to B&NES planning describing the work: which slate, from which quarry, what size, and why. Ask whether consent or an application is needed, and keep the reply. If it is, wait for the decision before ordering slate.
Finally, ask your roofer to quote for the material the council is likely to accept, and for an alternative if you want one, so you can compare. Insurers may also ask what was used, a further reason to record the work, and the page on slate storm insurance deals with that side.
