Re-covering in the same style: the general position
Planning law starts from a simple idea: only development needs permission. The Town and Country Planning Act 1990, in section 55(2)(a), excludes any work that does not materially affect the look of a building from outside. A new covering on a garage roof, in a similar material and the same shape, often lands on that side of the line.
The test is in the word materially. Swapping one grey sheet for another is barely noticeable from the pavement. Turning a flat felt roof into a pitched tiled one is obvious, and so is a bold new colour on a prominent corner plot. Where the look shifts, ask the council before you assume.
This describes the usual position, not a ruling on your garage. Every garage is a separate building on a separate plot, and the details matter.
Planning is also only one of two systems. Planning decides whether a change in appearance is acceptable. Building control checks that the work is safe and meets standards. A job can trigger either, both or neither, so a green light from the planners is not approval from building control. The page on the flat to pitched garage roof shows a case where both apply.
Height and pitch: where the council needs asking
The changes that raise questions are the ones that alter the garage's shape:
- A ridge higher than the present roof, or a steeper slope.
- A flat roof swapped for a pitched one, or the reverse.
- A new overhang, dormer or other projection.
- Walls raised to take a different roof.
Permitted development has its limits on height and projection, and those limits are framed differently for a house than for a building in its grounds. Whether they reach your garage depends on whether it is attached, how near it sits to a boundary and how it relates to the main house.
Since the answer turns on those details, write to the planners at your council, describing the height and pitch you have in mind, and ask whether permission is needed. Each Kent district handles enquiries its own way, so use the planning pages of whichever council covers the garage.
An enquiry costs far less than being told to alter a finished roof. The reply makes a useful paper to keep beside the quote, and it settles any argument with a neighbour who wonders whether the work was allowed.
Conservation areas, listed buildings and Article 4
Some places carry extra rules, whatever the garage looks like.
- Conservation areas: Thanet publishes 27, Canterbury 97, Dover 57 and Swale 51. Planning controls are tighter inside them.
- Listed buildings: works affecting a listed building's character need listed building consent under section 7 of the Planning (Listed Buildings and Conservation Areas) Act 1990. A garage in the grounds of a listed house may be caught by it.
- Article 4 directions: a council can withdraw particular permitted development rights across a defined area.
Which of these applies to your garage is a matter for the planning pages of the council that covers it. Look for the conservation area map and the list of Article 4 directions, then ask for the roof classes each direction withdraws, because the details differ by place.
The Canterbury World Heritage Site is treated as article 2(3) land, a category that also includes conservation areas. That affects dormers, not simple re-covering, and it only matters inside the site boundary.
For any of these, ask the officers early, well before the roof is ordered.
What to do before you order the roof
A short routine keeps a garage roof job out of trouble:
- Decide whether the roof keeps its shape or changes it.
- If the look will change, email the council a note and a photograph and ask whether permission is needed.
- Check the planning pages for a conservation area, a listed building or an Article 4 direction.
- Check the old sheets. Grey corrugated cement from before 2000 should be treated as asbestos until identified.
- Ask for the written price once the survey is finished, so the design and the cost are agreed together.
Keep the council's reply with the quote. When a buyer's solicitor asks years later whether the roof was approved, the paper answers for you.
MyJobQuote (October 2026) gives a typical UK range of £750 to £3,500 for replacing a garage roof, a national guide and not our price. Cost and planning are separate questions, and the survey settles the cost.
Our garage and asbestos roofs work covers the roof itself, and the page on a garage conversion roof covers another case where the rules change.
