The short answer
Usually yes. On a house, Class C permitted development normally covers a change of roof covering, so planning permission is not the first hurdle. The real checks are structural and technical: whether the roof can carry the new weight, whether its pitch suits natural slate, and whether a listed building or an Article 4 direction adds a consent step.
Does the roof structure suit slate?
Swapping one covering for another is a bigger step than replacing like with like, so the timber underneath comes first. At the survey we check the roof from inside the loft, taking in the rafters, which are the angled timbers holding the whole covering up, along with the battens and the wall plates, and we photograph what we see.
Weight follows. Building Regulations approval is needed, the Planning Portal says, if the new covering is 15 per cent or more heavier, and it recommends having an engineer or surveyor look at the structure first. Slates and tiles both vary widely in weight, so the manufacturers' figures for the exact products on each side of the swap decide it, whatever the material is called.
If the new covering turns out to be lighter than the old, the weight trigger is not the concern, though the fire-performance condition still applies. If it is heavier by the margin above, the job needs approval and the structural check goes into the paperwork.
Our answer on building regulations to replace a roof covers that route, and the survey tells us which applies.
Pitch decides which slate
Each covering has a lowest workable pitch, meaning the slope angle from horizontal, and a shallow roof can rule slate out. Cupa, a slate producer, points to BS 5534 for a floor of 20 degrees on natural slate, and says hooks have no place on slopes shallower than 25º.
Compare that with the tiles you may have now. Marley's published minimums run from 12.5 degrees for its Mendip 12.5 concrete tile up to 35 degrees for its plain concrete tile, with a double Roman at 22.5 degrees for a smooth finish; check each data sheet. So a roof tiled in a low-pitch concrete tile may sit below what natural slate allows, even though the tile it carries today is perfectly legal.
The pitch is measured on the day, not estimated from the garden. Where it is too shallow, the honest options are a different covering or keeping what you have. The maker's published minimum for the exact product has the last word.
A slate roof also brings fixing choices, such as tingles or hooks, so the pitch figure affects the method as well as the material.
Planning, listing and conservation areas
Class C of the permitted development order deals with other roof alterations to a dwellinghouse, re-roofing among them, which makes a new covering on a house permitted development in the normal run of things. Flats fall outside the term dwellinghouse and carry no such rights. Class C has no carve-out for conservation areas, National Parks or National Landscapes.
That leaves three checks. A listed house keeps those rights too, yet listed building consent is also required for work touching its character, so a change of material goes to the council first. An Article 4 direction lets a council remove chosen permitted development rights in a set area; ask whether one covers your street.
Basingstoke and Deane is the one council whose roof-related directions we can describe. Its directions for four conservation areas want original Welsh slate and clay roofing kept, and say modern substitutes, concrete tiles and artificial slate among them, are unlikely to pass. Moving to natural slate fits that stance, but the point shows why the check matters.
For any other address, check with the council's planning team.
What changing to slate costs, and what it adds
The total is shaped by the slate chosen, the roof's area, how the scaffold must stand and the state of the timber once the tiles are lifted. MyJobQuote (Oct 2026) gives around £7,800 as the average for fitting a slate roof; treat that as a national typical figure, separate from any price we would write. Sources differ for a whole re-roof, so see our new roof cost answer for the spread.
The covering also changes how long the roof should last. HomeBuilding gives Welsh slate as 100+ years, and plain concrete tiles as 40-50 years. These are typical lives, not promises, and the underlay, battens and fixings underneath have to be sound for the slates to reach them.
Scaffolding that occupies the highway needs a licence from the highway authority, which we sort out alongside the scaffolder. Ask for a single written total that names the slate by type and origin.
If you would like to see how a slate roof is dressed at the ridge and verge, the slate roofing page explains it, and the roof replacement page covers how we run a full re-roof.
