Roof ConstructionCost Calculator

New roof construction costs in the UK range from £5,000 to £25,000+ depending on size, pitch, and materials. For a typical 3-bedroom semi-detached house with a pitched concrete tile roof (around 60-70 m2), expect to pay £7,000-£14,000 including labour, materials, scaffolding, and felt underlays. Natural slate on the same house runs £12,000-£20,000. Flat roof construction on a single-storey extension typically costs £2,500-£6,000 for a GRP (fibreglass) finish. These figures are for new-build construction where there is no stripping of existing materials. Use the calculator above for a detailed estimate based on your specific roof area and materials.

UK roof replacement costs range from £65-£205 per m² depending on material and pitch. Felt/GRP flat roofs are cheapest (£65–£105/m²), concrete or clay tiles sit in the middle (£80–£130/m²), and natural slate is the most expensive (£115–£185/m²). Labour accounts for roughly 35–45% of the total. Always get 3 quotes from NFRC-registered roofers.

A typical UK semi-detached house has a roof area of 55–75 m². Using concrete tiles and stripping the old roof, expect a total cost of £6,500–£12,000 depending on pitch, access, and local labour rates. London and South East prices run 20–30% higher than the national average. This includes materials, labour, scaffolding, and disposal.

Yes — stripping an existing roof typically adds £8–£15 per m² and requires skip hire. Many customers forget this until the quote arrives. Including it upfront prevents disputes and shows professionalism. The calculator adds this automatically when you toggle it on.

Start with the actual roof surface area (not the floor footprint — add roughly 15% for a medium pitch). Multiply by the material cost per m² for your chosen tile or slate. Add a 10–15% wastage allowance for cuts and breakages. Don't forget underlays, battens, ridge tiles, flashing, and fixings — these add a further £8–£20 per m² depending on specification.

Felt flat roofs typically last 10–15 years; GRP (fibreglass) flat roofs last 25+ years and cost slightly more to install but far less over a lifetime. Converting a flat roof to a pitched tile roof is a much larger structural project, typically costing £15,000–£30,000+. In most cases, upgrading to GRP rather than converting the structure is the better value option.

Steeper pitches increase both material requirements (more overlap needed) and labour time. A steep pitch (35°+) can add 30–45% to labour costs compared to a flat roof due to safety equipment, slower working pace, and more complex detailing around ridges and valleys.

Natural slate roof replacement costs £115–£185 per m² in the UK in 2026, including labour, materials, battens, underlay, and disposal. For a typical 3-bed semi (60–75 m²), a full slate re-roof costs £9,000–£18,000. Natural slate lasts 80–150 years — significantly longer than concrete tiles (40–60 years). Spanish slate is the most common choice in the UK at £90–£130/m² total; Welsh slate commands a premium at £150–£250/m² for its provenance and quality. Use the calculator above and select 'Natural Slate' as the material to get a full estimate for your roof area.

For most homeowners replacing a roof that will stay in the family or be sold at a premium, natural slate is worth the investment. It lasts 2–3× longer than concrete tiles, adds kerb appeal, and may be required in conservation areas. The cost difference between tile and slate re-roofing is typically £3,000–£6,000 on an average house. Spread over 80 years of lifespan vs 40 years for tiles, the lifetime cost per year is similar. The calculator above shows the cost difference for your specific roof area.

In most cases, like-for-like roof replacement is covered by permitted development rights and does not require planning permission. Exceptions include listed buildings, conservation areas, or if you are changing the roof shape, materials, or adding features like dormer windows. Always check with your local planning authority before starting work.

Roofers typically charge £200–£440 per day in the UK, depending on experience, location and whether they bring a labourer. Experienced roofers in London charge £350–£500+/day. For large jobs, many roofers price per m² (£35–£60 for labour only) rather than day rate. Always ask whether scaffolding is included in the quote.