Estimate the cost of replacing your roof with concrete tiles, slate, clay tiles, or flat roofing
A roof replacement is one of the most significant home maintenance projects you will face as a UK homeowner. Whether tiles are slipping, the felt has failed, or you simply have an ageing roof that has reached the end of its life, understanding the costs involved helps you budget effectively and evaluate contractor quotes with confidence. The cost of a new roof depends primarily on two factors: the size of the roof (measured in square metres) and the material chosen. Concrete tiles are the most common and affordable option for UK homes, while natural slate is the premium choice offering exceptional longevity. Clay tiles provide an attractive middle ground, and flat roofing materials (EPDM rubber or modern felt systems) are used for garages, extensions, and dormer roofs. Scaffolding is almost always required for pitched roof work and adds a fixed cost to the project. This calculator provides low, mid, and high estimates based on current UK trade averages.
To estimate your roof replacement cost: 1. Enter the roof area in square metres. If you do not know the exact figure, a rough guide is that roof area is approximately 1.3-1.5 times the floor area of the top storey (to account for the pitch). A typical UK semi-detached house has a roof area of 50-70 m2. A detached house is usually 70-120 m2. 2. Select the roofing material. Concrete tiles are the most popular budget option. Slate (natural or reconstituted) is more expensive but can last 75-100 years. Clay tiles offer a traditional look. Flat roof options use EPDM rubber or multi-layer felt systems. 3. Toggle the scaffolding option. Scaffolding is required for virtually all pitched roof replacements. A standard scaffold for a two-storey house costs 600-1,500 depending on the property size and access. Only toggle this off if your contractor includes scaffolding in their rate or the project does not require it (some single-storey flat roofs). 4. Review the three cost estimates and the average cost per m2, which is useful for comparing quotes from different roofing contractors.
The calculator uses UK trade average rates per square metre for each roofing material: Concrete tiles: 50-110 per m2 (supply, strip, and re-tile) Slate: 80-200 per m2 (supply, strip, and re-slate) Clay tiles: 70-160 per m2 (supply, strip, and re-tile) Flat roof (EPDM/felt): 45-100 per m2 (supply, strip, and re-cover) Total cost = roof area (m2) x rate per m2 If scaffolding is included, a flat cost is added: Scaffolding: 600 (budget) to 1,500 (premium) These rates include stripping the old covering, inspecting and replacing any damaged battens or felt, laying new materials, and cleaning up. They assume standard access conditions and a straightforward roof layout. Complex roofs with many hips, valleys, or dormers will cost more.
Inputs: Roof area: 60 m2, Material: Concrete tiles, Include scaffolding: Yes
Inputs: Roof area: 40 m2, Material: Slate, Include scaffolding: No
Inputs: Roof area: 20 m2, Material: Flat roof, Include scaffolding: No
Roof replacements do not typically require planning permission unless you are changing the roof height or the property is listed or in a conservation area. However, Building Regulations apply to thermal performance requirements under Part L (energy efficiency). If more than 25% of the roof is being replaced, you must upgrade insulation to current standards. Always use a contractor registered with the National Federation of Roofing Contractors (NFRC) or a similar trade body. Check that they have public liability insurance and provide a written guarantee. Prices are based on 2026 UK trade averages and include VAT at 20%.