- Replacing a roof like-for-like rarely needs planning permission, but it usually does need Building Control to be notified.
- Re-covering more than half of a roof is a renovation of a thermal element under Approved Document L, so the insulation is normally brought up to current standards at the same time.
- Changing from a light covering such as slate to heavier concrete tiles needs a structural check of the roof timbers under Approved Document A.
- You should receive a completion certificate at the end. Keep it; solicitors ask for it when you sell.
Planning permission and Building Regulations are different things
People often ask whether they need permission to replace a roof and get two different answers, because there are two different systems.
Planning permission is about what the building looks like and its effect on neighbours. Replacing a roof like-for-like does not normally need planning permission. It can if the house is listed, if it is in a conservation area with an Article 4 direction removing permitted development rights, or if you are changing the shape of the roof.
Building Regulations are about how the building performs: structure, fire, insulation, ventilation. They apply to most re-roofing whether or not planning permission is needed, and they are what this guide is about.
When re-roofing becomes a thermal element renovation
Under the Building Regulations, a roof is a thermal element, and under Approved Document L (conservation of fuel and power), renovating a thermal element is building work that has to be notified to Building Control and has to meet the energy standards.
The trigger is the proportion of the roof being renewed. Approved Document L treats the work as a renovation of the thermal element where more than 50 per cent of the surface of the individual element is being renovated, or where more than 25 per cent of the total building envelope is. In practice, stripping a roof and re-covering it is a renovation of the thermal element, and a full re-roof always is.
If you are having the whole roof, or most of one slope, stripped and re-covered, Building Control should be notified and the insulation should be checked. Replacing a few tiles or a small area of repair does not trigger it.
Do you have to add insulation?
Where the work is a thermal element renovation, Approved Document L says the element should be upgraded to meet the current target U-value where it is technically, functionally and economically feasible. For a pitched roof with a cold loft, that means bringing the loft insulation up to current standards, typically around 270 to 300 mm of mineral wool, which is cheap and easy while the roof is being done. The economic test is a simple payback of 15 years or less, which loft insulation passes comfortably.
For a room-in-roof or a flat roof over a heated room, the insulation goes in the roof structure itself and the detailing is more involved. It should still be on the quote.
Who tells Building Control?
Either you, the homeowner, submit a Building Notice or full plans application to Barnsley Council's Building Control (or an approved inspector), and pay the fee, or the roofer does it as part of the job. The exception is a roofer registered with a Competent Person Scheme that covers roofing, who can self-certify the work and notify the council on your behalf, which saves the fee and the inspection.
Whichever route, at the end you should receive a completion certificate. Keep it. Solicitors ask for it when you sell.
Whether Roofline notifies through a Competent Person Scheme or through a Building Notice will be set out here once confirmed.
Changing the covering: the structural check
Roof coverings weigh very different amounts. Natural slate is light. Concrete interlocking tiles are roughly twice the weight of slate, and clay plain tiles heavier still per square metre laid. Yorkshire stone slate is heavier than all of them.
If you change from a lighter covering to a heavier one, for instance a Victorian slate roof re-covered in concrete tiles, the rafters and purlins may not have been designed for the load. Approved Document A (structure) requires the roof structure to be checked and, if necessary, strengthened. A competent roofer will raise this before quoting, and on an older terrace a structural engineer's check is money well spent. Going from a heavier covering to a lighter one does not usually cause a structural problem, though the pitch has to suit the new material.
Other regulations that come up
- Ventilation (Approved Document C and F, and BS 5250). Adding insulation without ventilation causes condensation in the loft. A re-roof should include eaves or ridge ventilation or a breathable underlay designed for the job.
- Fire (Approved Document B). Relevant where a roof is close to a boundary, mainly for the covering's fire rating. Standard tiles and slates are fine.
- Party Wall Act. Working on a party wall chimney stack or the roof junction on a terrace or semi may need a party wall notice to the neighbour.
- Work at Height Regulations 2005. Not a Building Regulation but a legal requirement on the roofer: safe access, edge protection, scaffold. If the quote does not include it, walk away.
How Roofline handles it
We tell you at quote stage whether the work is notifiable, what insulation upgrade applies and how the notification will be made. Ventilation is designed in. If you are changing covering, we flag the structural question before anything is ordered. It is part of doing the job properly, not an optional extra.
For the cost side of a re-roof, read our roof cost guide.
This guide is general information about roofing in England and is not a substitute for advice about your own roof. Standards and regulations are updated from time to time; check the current edition before relying on a specific requirement. Written by Roofline, roofers in Barnsley. Last reviewed September 2026.
