How much a new roof costs in the UK
A re-roof is one of the biggest single jobs a house needs, and quotes for the same property can differ by thousands of pounds. This roofing cost calculator starts from the footprint of your house, converts it into real roof area using the pitch, and prices the covering, labour, scaffolding and the optional extras separately — so you can see where a quote’s money is going.
Step 1: roof area from footprint
A sloping roof has more surface than the ground it covers. Measure the footprint (including overhangs), then multiply: ×1.04 for a 15° pitch, ×1.15 for 30°, and ×1.41 for 45°. A 50 m² footprint at 30° is 57.5 m² of roof.
Step 2: wastage by roof shape
A simple gable roof needs about 5% extra covering. Hips and valleys mean many angled cuts, so a hipped roof needs about 12% and a complex roof with dormers and valleys around 18%. They also slow the roofer down.
Worked example: a 50 m² footprint, 30° gable roof
57.5 m² of roof, 60.4 m² of covering with wastage, about 4.8 days of labour at £280 a day.
| Covering | Price per m² | Covering cost | Labour | Scaffolding | Total |
|---|---|---|---|---|---|
| Concrete tiles | £45 | £2,717 | £1,342 | £900 | £4,959 |
| Clay tiles | £85 | £5,132 | £1,342 | £900 | £7,374 |
| Natural slate | £140 | £8,453 | £1,342 | £900 | £10,694 |
Before strip-off and disposal, new battens and membrane, timber repairs, and VAT where charged. Those lines are optional in the calculator.
What drives the price
Pitch
Steeper roofs have more area and are slower to work on. The same 50 m² footprint as a 45° hipped roof becomes 70.5 m², needs about 79 m² of covering with wastage, and takes roughly seven days instead of five.
Covering
Concrete tiles are cheapest and last around 50 years. Clay costs nearly twice as much but lasts longer and weathers well. Natural slate is the most expensive and can last a century or more. In conservation areas, the choice may be made for you.
Access
Scaffolding is hired for the job whatever the roof size, so it is a bigger share of a small roof. Terraced houses, conservatories below and busy roads can all push it up.
The lines quotes treat differently
Strip-off and disposal
Removing the old covering, battens and felt, and taking it away in skips, often costs more than people expect. On a re-roof the new tiles are rarely the largest line. Ask whether each quote includes it.
Battens, membrane and timber
A full re-roof normally includes new battens and a breathable membrane. Rotten rafters or fascias are only found once the old roof is off, so a sensible quote includes a rate for timber repairs rather than a fixed price.
Flat roofs
A different construction
A flat roof has no pitch, so its area equals its footprint, and it is covered with a membrane rather than tiles. The calculator applies 5% wastage and a faster laying speed for flat roofs. Common coverings are EPDM rubber, GRP fibreglass and torch-on felt.
What to check
Flat roofs fail mostly at edges, joints and outlets rather than across the middle. Ask what decking is under the covering — if it is wet or rotten, it must be replaced, which is often the larger part of the cost on garages and extensions.
Comparing roofing quotes
Same scope, line by line
- Covering type, brand and quantity
- Strip-off, skips and disposal
- Battens, membrane, ridge and verge details
- Scaffolding, including hire length
- A day rate or allowance for timber repairs
- Guarantee length, and whether it is insurance-backed
Building Regulations
A full re-roof usually falls under Building Regulations in England and Wales, and can require the roof insulation to be brought up to current standards. Roofers registered with a competent person scheme can certify the work without a separate application. Ask who is handling it before work starts.
Repair, replace, or add solar first?
A few slipped tiles or a leaking valley can be repaired for a fraction of a re-roof. Widespread cracked tiles, sagging, or failing felt usually mean replacement. If you are thinking about solar panels, do the roof first — removing panels to fix a roof later means paying for scaffolding twice. Check the payback with the solar panel calculator.
For the full picture, read our guide to new roof cost in the UK. Planning a wider project? The room renovation cost calculator and budgeting a renovation help plan the rest. These figures are estimates, not a quote.