Roof area and pitch
Larger and steeper roofs need more material, more labour and more safety setup. A steep roof can take longer even if the area is similar.
Roof replacement cost calculator
Roof Replacement Cost Calculator UK
Estimate the cost of replacing a UK roof based on roof size, roof type, access, scaffolding, roof condition, material specification and region. Use this calculator when your roof is ageing, repeatedly leaking, structurally tired or due for major renewal.
Do you need roof replacement or roof repair?
The first decision is whether the problem is localised or part of wider roof failure. A small repair can be the right choice for isolated damage, but repeated leaks or widespread age-related issues can make replacement better value.
| Roof situation | Better starting point | Reason |
|---|---|---|
| One missing tile | Roof repair | A small localised fix may be enough. |
| Isolated leak | Roof repair | The issue may be flashing, a slipped tile or a small failed area. |
| Repeated leaks | Roof replacement | Repeated problems can indicate wider failure of the roof covering or underlay. |
| Failing underlay | Roof replacement | Underlay failure usually affects more than one visible patch. |
| Sagging roof | Roof replacement | Structural movement needs proper inspection and may require major work. |
| Old roof near end of life | Roof replacement | Replacement may be more practical than repeated short-term repairs. |
How roof type changes replacement cost
Material choice affects labour time, waste handling, roof weight, detailing and long-term value. Use this page for the broad replacement estimate, then move into the roof-type calculator that matches your project.
Default UK residential roof
Tiled roof replacement
Use this for concrete or clay tiled roofs. This is often the baseline comparison for UK roof replacement.
Premium comparisonSlate roof replacement
Use this for natural or artificial slate where material cost, installation skill and roof structure affect the estimate.
Extensions, garages and dormersFlat roof replacement
Use this for flat or low-pitched roofs where membrane type, insulation, drainage falls and deck condition matter.
Typical UK roof replacement cost ranges
These are broad planning ranges. Use the calculator above for a more specific estimate based on size, access, material, condition, region and contingency.
| Project type | Typical range | Best next calculator |
|---|---|---|
| Small flat roof replacement | £1,000–£5,000+ | Flat Roof |
| Standard tiled roof replacement | £4,000–£18,000+ | Tiled Roof |
| Slate roof replacement | £8,000–£30,000+ | Slate Roof |
| Full roof replacement | £5,000–£25,000+ | Roof Replacement |
| Large or complex roof replacement | £15,000–£40,000+ | Cost per m² |
What affects roof replacement cost?
Roof area sets the base estimate, but the final price is usually shaped by access, scaffolding, material choice, pitch, roof shape and the condition of the roof underneath the visible covering.
Scaffolding and access
Property height, parking, side access, waste removal and neighbouring buildings can change the setup cost before materials are priced.
Material choice
Concrete tiles, clay tiles, slate and flat roof systems sit in different cost bands because material price and installation time vary.
Hidden condition
Rotten battens, failed underlay, timber damage, poor ventilation or old patch repairs can add cost once the roof is stripped.
Roof complexity
Valleys, hips, chimneys, dormers, skylights and roof junctions slow installation and increase detailing work.
Region and labour rates
Labour, scaffolding, waste and travel costs vary by region. London and parts of the South often sit higher than lower-cost regions.
Already have a roof replacement quote?
A quote can look high or low until it is compared against the roof area, access, material and scope. Use the Roof Cost per m² Calculator to check whether the quote sits in a realistic range. Then compare it with the relevant material calculator for tiled, slate or flat roofing.
Replacing a roof as part of an extension?
Roof design can affect extension cost, especially when the project includes a flat roof extension, pitched roof tie-in, matching tiles, rooflights, insulation, drainage or structural changes.
If the roof is part of a wider build, compare this estimate with the extensions cost calculators and the Home Extension Cost Calculator. For roof-specific planning, compare flat roof replacement with tiled roof replacement.
How this roof replacement estimate is calculated
The calculator starts with a roof type and base cost per m², then adjusts the range using roof complexity, access and scaffolding, existing condition, specification level, regional labour market and contingency.
This approach is designed for early planning, not fixed quoting. Roofing work often changes once the old covering is stripped and the underlay, battens, decking or timbers can be checked properly.
For more detail, read our methodology, pricing data and how costs are calculated.
Roof replacement decision paths
Use these paths to move from a rough concern to the calculator that gives the most useful next estimate.
My roof is old
Start with this Roof Replacement Cost Calculator, then compare tiled roof replacement with slate roof replacement if material choice is open.
My roof is leaking
Start with the Roof Repair Cost Calculator if the leak seems isolated. Use this page if leaks are repeated, widespread or linked to an ageing roof.
I have a quote
Use the Roof Cost per m² Calculator first. Then compare the result against this replacement calculator and the relevant roof-type page.
I’m replacing a roof on an extension or garage
Start with the Flat Roof Replacement Cost Calculator if the roof is flat or low-pitched. For wider budgeting, use the extensions cost hub.
Roof replacement cost FAQs
How much does roof replacement cost in the UK?
A typical roof replacement can range from around £5,000 to £25,000 or more. Size, material, pitch, scaffolding, access, complexity and hidden condition all affect the final price.
Is it cheaper to repair or replace a roof?
Repair is usually cheaper for isolated damage. Replacement can be better value when leaks are repeated, the roof is ageing, underlay has failed or the covering is widely deteriorated.
What is the cheapest roof replacement option?
A simple tiled roof is often cheaper than a slate roof. Small flat roofs can cost less in total, although material choice and deck condition still matter.
How do I estimate roof area?
Roof area is usually larger than the building footprint because of pitch, overhangs and roof shape. If you are unsure, use a cautious estimate or compare quotes using cost per m² later.
Does scaffolding affect roof replacement cost?
Yes. Scaffolding can be a significant cost, especially for taller properties, difficult access, terraced houses, restricted parking or complex roof shapes.
Is slate more expensive than tile?
Slate is usually more expensive because the material can cost more and installation often needs more time, care and specialist labour.
Should I use cost per m² to compare roof quotes?
Yes, but use it as a benchmark. Cost per m² helps compare quotes, but it does not fully explain pitch, access, scaffolding, material quality, detailing or hidden damage.
Are CostIntel estimates fixed quotes?
No. They are planning estimates based on typical UK roofing scopes and cost drivers. A roofer needs to inspect the property before giving a fixed quote.