The short answer
Often yes, though not on every house. Re-roofing a house normally falls under Class C of the permitted development order, so a new covering rarely needs planning permission. Two questions come before the order for tiles goes in: would the tiles push the covering 15 per cent or more heavier, which brings in Building Regulations, and is the house listed or in a conservation area?
Moving from slate to tile alters the look, the load on the timbers and the way the roof is fixed. Your pitch, your rafters and your address decide the answer.
Weight and the 15 per cent test
Slate and tile press down on a roof differently, and the angled beams underneath, called rafters, were cut to suit the first covering. The Planning Portal puts its trigger at 15 per cent or more extra weight from the new material. Approved Document A, the structural guidance, calls a rise in roof loading above 15% significant. Those two wordings differ by a hair, so aim to stay under 15 per cent and nobody has to argue about which applies.
How do you find out how much heavier a tile is?
Every maker prints a weight per square metre on its data sheet. Your roofer sets the old covering against the new, adds the battens and fixings, and works out the difference across your whole roof. Where the sum comes out close, or the rafters look tired, the Planning Portal advice is to ask an engineer or surveyor to run the numbers first.
Going past 15 per cent does not end the plan. It turns the job into a Building Regulations application, perhaps with extra strengthening. Our page on when a new roof needs a structural engineer explains how that step runs, and the roof replacement hub covers the wider job.
Planning: Class C and the appearance test
Re-roofing sits in Class C of the permitted development order, the class dealing with changes to a house roof. On that footing, replacing one covering with another is normally allowed without applying for planning permission. One limit bites with deep profiles: the new covering may rise no more than 0.15 metres above the plane of the old roof slope, so a chunky tile on thin slate needs checking.
What is the appearance test?
Section 55 of the 1990 planning Act treats work that leaves a building's outside look materially unchanged as not being development at all. A swap from grey slate to a very different tile can alter that look, which is why we lean on Class C rather than this test. A similar colour and a low profile keep you comfortably inside both.
Does a building divided into flats work the same way?
No. Flats fall outside the order's meaning of a dwellinghouse, so this route is shut to a block and to a single flat in a converted house. For a flat, or a house split into flats, ask Somerset Council's planning team before ordering a thing.
Conservation areas, Article 4 and listed homes
A conservation area counts as article 2(3) land, which takes away permitted development dormers. Class C carries no article 2(3) exclusion, so a new covering can stay permitted there. The catch is Article 4, a direction that lets a council withdraw chosen permitted development rights over a set area. Somerset Council lists Article 4 directions for several spots around Taunton, among them Wellington and Staplegrove Road. Each covers different ground, and one phone call with your address on hand settles it.
What about a listed house?
Listing leaves Class B and Class C rights in place, yet listed building consent is also required for works touching the features that earned the listing. Trading slate for tile can do exactly that. Within Exmoor National Park, Exmoor National Park Authority takes the decisions, not Somerset Council.
This is where slate stays slate. On a listed or conservation-area roof, the right answer is often to repair or renew the slate and keep the look the street already knows.
Pitch, battens and lifespan
Each covering has a lowest workable pitch, meaning the steepness of the slope. Under BS 5534, natural slate is indicated for roofs of 20 degrees and above. A smooth Marley Double Roman concrete tile needs 22.5 degrees, and a Marley plain tile needs 35 degrees. A tile laid shallower than its limit can let wind-driven rain in, so the pitch picks the tile before taste does.
Will the battens and fixings change?
Yes. Slate and tile are laid to different spacings, so the battens (the laths nailed across the rafters) are set out afresh. Fixings follow BS 5534, guidance on good practice rather than a statute, and ridge and hip tiles are held mechanically, never on mortar alone.
How long does each covering last?
CORC puts well-maintained slate at 100+ years. Marley's figure for its concrete tile is around 60 years, offered as an expectation and no warranty. A sound slate roof is often better mended than swapped, and the swap rarely pays back the extra hassle of re-battening the whole slope.
Send a photo and your address and we will book a visit: you see photographs taken on your own roof, then receive a single total in writing. See our slate roofing page for the repair side.
More on changing the covering
What if my roof pitch is too shallow for the tile I want?
Then that tile is the wrong choice for the roof. Each maker publishes a minimum pitch, such as 22.5 degrees for a smooth Marley Double Roman and 35 degrees for a Marley plain tile, and a covering laid below its limit can admit water. The pitch is taken on the day we visit, and the covering we recommend has to suit it.
Will a Taunton conservation area stop me changing the covering?
Not automatically. A conservation area removes permitted development dormers, and Somerset Council lists Article 4 directions for some places near Taunton. A short call to Somerset Council's planning team, with your address ready, settles the question before you order a single tile, and saves you a costly mistake on the scaffold.
The full picture: Roof replacement and new roofs in Taunton ยท More short answers