One of the most frustrating aspects of receiving a Section 20 major works bill is having no idea whether the figures are reasonable. Construction costs aren’t published on a price list. Labour rates vary by region. Materials fluctuate. So how is a leaseholder supposed to know if £85,000 for roof works is fair, or whether they’re being robbed?
This guide gives you the benchmarks we use as qualified surveyors — the same data we apply when reviewing Section 20 bills. These are indicative rates as of 2025, based on published BCIS data and our own live cost databases. They’re a starting point, not a definitive answer, but they’ll give you a sense of where your bill stands.
Roofing Works
Roof replacement is one of the most common major works items in leasehold blocks, and one of the most frequently inflated.
- Felt flat roof replacement (standard specification): £70–£110 per m²
- Felt flat roof — premium specification (e.g. GRP or hot melt): £120–£180 per m²
- Pitched roof — strip and re-tile (concrete tiles): £60–£95 per m²
- Pitched roof — natural slate: £100–£160 per m²
- Lead valley and flashing work: £80–£140 per linear metre
If your flat roof replacement is quoted at £200/m² with no explanation of the specification, that’s a red flag. If it’s described as “high-performance warm-roof system” with membrane overlay, £180 might be justified — but the specification should make that clear.
External Decoration and Rendering
External redecoration is another common Section 20 item, and the cost per m² varies enormously by specification and access method.
- External painting (masonry, 2 coats): £18–£35 per m²
- External painting (timber windows, frames): £25–£45 per m²
- Render repair and repaint: £45–£85 per m²
- Full render removal and replacement: £80–£150 per m²
- External wall insulation system (EWI): £120–£200 per m²
Scaffolding
Scaffold is often a major component of a Section 20 bill and one of the areas most prone to overspecification. Scaffold costs depend heavily on duration, height, and complexity, but some benchmarks:
- Standard tube and fitting scaffold — erect, hire (4 weeks), dismantle: £8–£15 per m² of scaffolded elevation
- Birdcage scaffold (internal): £12–£20 per m²
- Scaffold hire extensions: £0.50–£1.00 per m² per week
We have reviewed Section 20 bills where scaffold was specified at twice the necessary coverage, extended for periods far beyond the likely works duration, and charged at rates significantly above the market. This is one of the most reliably inflated line items we see.
Communal Area Redecoration
- Internal painting (walls and ceilings, two coats, emulsion): £12–£20 per m²
- Gloss or satin to woodwork (doors, skirting, architrave): £18–£30 per m²
- Full internal redecoration of stairwell (prep, fill, 2 coats): £20–£35 per m²
Lift Replacement and Refurbishment
- Lift refurbishment (cab, controls, modernisation): £25,000–£60,000 depending on spec and number of floors
- Full lift replacement (8-floor building, standard spec): £80,000–£140,000
Project Management and Contract Administration
This fee — charged by the managing agent for overseeing the works — should typically be:
- Under £50,000 contract value: 8–12% of contract sum
- £50,000–£200,000: 6–10%
- Over £200,000: 4–8%
If your bill shows a project management fee of 18–25%, that is almost certainly excessive. On a £60,000 contract, the difference between 10% and 20% is £6,000 — money taken from leaseholders, above what any professional body would consider reasonable.
How to Use These Figures
These benchmarks will tell you whether your bill deserves scrutiny. They won’t tell you definitively whether your specific bill is fair — that depends on location (London costs are typically 15–25% above national average), specification, access difficulty, and the condition of what’s being replaced. That’s where a professional assessment comes in.
But if your roof replacement is coming in at double these rates with no obvious justification, or your scaffold bill looks like it’s enough to cover Buckingham Palace, you have grounds to push back.
Think your bill might be inflated? Get an independent assessment from Section20.org.uk — 48-hour turnaround, fixed fee. Email info@rapidqs.uk, WhatsApp us at +44 7438 628277 (5-minute response guaranteed), or fill in our contact form at section20.org.uk