The short answer
No, not for a like-for-like replacement. Fitting the same kind of covering to the same roof leaves the outward look of the garage unchanged, so section 55 of the Town and Country Planning Act 1990 does not count it as development. A taller roof, or a flat one turned into a pitched one, is another matter, and Somerset Council's planners should hear about it first.
Swapping worn felt or sheets for the same again is upkeep in planning terms. The questions begin when the finished roof looks different from the old one.
When a like-for-like re-cover needs no permission
Planning law turns on one plain question: will the building look different from outside afterwards? The 1990 Act, at section 55(2)(a), excludes works whose result is not a visible change to the outer face of a building. Upkeep jobs like this one are what that wording was written for. New felt, a fresh membrane or sheets of the same profile and colour laid on an existing garage roof sit comfortably inside it.
Does a flat garage roof replacement count?
Yes, while the roof stays flat and at the same height. Stripping worn felt and laying a new waterproof layer changes nothing a neighbour would spot from the lane. The deck beneath, the sheet of timber the membrane lies on, can be renewed in the same visit, and our guide to garage roof deck replacement explains when that becomes necessary.
For a house, Class C of the permitted development order deals with roof alterations, and re-covering normally falls inside it. A detached garage leans on the section 55 test alone. An attached garage is worth confirming with the planning team before the job is booked in.
Changes that do alter the look of the roof
The picture shifts once the roof looks different. A higher ridge, a deeper fascia board, a new pitch, or a flat roof reshaped into a pitched one all alter the outward appearance, so the section 55 shelter stops applying. Whether permission is then required depends on the building and the plot, and that judgement belongs to the council, not to a roofer or a neighbour.
Should I ask before I change the shape?
Yes. Write to the planners at Somerset Council. If the garage stands inside Exmoor, write to Exmoor National Park Authority instead, which holds the planning role within the Park. A short written enquiry costs far less than taking down a roof that was built wrong. Our answer on putting a pitched roof on a garage looks at that exact case.
Here is one detail from the rules on houses. Class C refuses a roof alteration standing proud of the original slope by more than 0.15 metres, which shows how closely the rules watch anything that sticks out past what was there before. It also tells you why a taller garage roof draws the planners' eye.
Listed, conservation and Article 4 places
Some addresses carry extra layers of control. A listed building needs listed building consent for any work touching its character, and the roof covering can be part of that, even when permitted development would otherwise let the work go ahead. A garage inside a conservation area, or standing within the grounds of a listed house, deserves a phone call before anything is ordered.
What is an Article 4 direction?
It is a direction from the local planning authority that withdraws permitted development rights across a set area. Applications can then be required for jobs that would normally need none. Somerset Council keeps a published list, and Wellington, Milverton and Taunton's Staplegrove Road all appear on it. Each direction has its own scope, so we send the customer to the planners for that answer instead of guessing at it.
When a garage roof sits in one of these places, we raise the consent route at the survey, before the written price is settled, so no materials are ordered for a roof the council has yet to see. That keeps the programme honest and the paperwork in the right order.
Planning is one gate and Building Regulations another
Planning permission and Building Regulations are separate systems, and a roof can clear one without touching the other. The Planning Portal sets a re-roofing test: below 25 per cent of the building envelope and below 50 per cent of the roof, building control is not usually involved. A garage roof renewed from edge to edge may pass both limits, so ask before you start, and ask in writing.
What if the garage gets a heavier roof?
Building Regulations approval comes into play once the new covering weighs 15 per cent or more beyond the old covering. The Planning Portal's advice is to get the timbers checked, by a surveyor or a structural engineer, before ordering. Part L is the energy section of the regulations, and it treats re-laying the waterproofing of a flat roof as renovation.
Somerset Building Control on 0300 303 7790 is the body to ring. Our repair or replace guide helps you settle scope before you ring, and the garage and asbestos roofs page lists the rest of our garage work. Our part starts with a visit to look over your garage roof and show you what we find.
More on garage roofs and the council
Do I need permission to turn a flat garage roof into a pitched one?
Take that one to the council. A pitched roof changes the height and outline, so the exemption for like-for-like work no longer covers it. Put the plan to Somerset Council's planning team, and ask building control about the structure, before any price is agreed or any materials are ordered.
Does replacing an asbestos cement garage roof need permission?
Swapping asbestos cement sheets for a similar sheeted covering is a re-cover, so the planning test is the same as for any other garage roof. The asbestos side follows HSE guidance on careful removal and on waste travelling under a consignment note, and we check that at the survey.
The full picture: Garage and asbestos roof replacement in Taunton ยท More short answers