A flat roof replacement strips the old covering from a low-pitched roof and lays a new waterproof system, usually EPDM rubber, GRP fibreglass or torch-on felt, over a sound deck with correct falls, upstands, trims and outlets so rainwater drains away.
Anyone planning a new flat roof in Barnes wants three things: a clear price, a realistic timetable and a tidy job. We publish a guide of £2,600–£5,800 including VAT for London up front, explain that work normally takes 1–3 days for most roofs, and confirm both in writing after a free survey of your property.
- Guide price
- £2,600–£5,800 inc VAT
- Time on site
- 1–3 days for most roofs
- Postcodes
- SW13, SW14, SW15, TW9 and W4
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
What should you budget for a new flat roof in Barnes?
The costs listed here are typical for a new flat roof around Barnes and include VAT. They reflect labour and material costs in London, about 30% above the national guide, giving a range of £2,600–£5,800. Exact pricing depends on your home, so we only fix it once a free site survey is done.
| Type of job | What it usually involves | Guide in Barnes |
|---|---|---|
| Small roof (up to 8m²) | A dormer, bay, porch or small garage roof re-covered in EPDM or GRP. | £1,050–£2,600 |
| Extension or garage (15–25m²) | A typical extension or single garage roof stripped and re-covered. | £2,600–£5,800 |
| Large or new warm roof | Larger roofs, or roofs needing a new deck and insulation build-up. | £5,200–£11,500 |
Expect these to shape the final quote:
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Insulation upgrades and changes to roof height at edges
- Number of rooflights, pipes and upstands to detail
Scope of the work
- Survey of the covering, deck, falls, upstands and drainage
- Stripping and disposal of the old roof covering
- Replacement of rotten or soft deck boards
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
- New trims, outlets and gutter connections
Building in Barnes
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
Terraces suit side-return extensions and rear dormer loft conversions; interwar semis commonly take hip-to-gable lofts. Shared party walls, restricted parking and conservation rules often shape the plans and the programme.
That mix of housing shapes how we approach a new flat roof in Barnes: the age and construction of your home affect the materials, the method and, in the end, the price.
Permissions for a new flat roof in Barnes
For anyone in Barnes, the relevant framework is England's. The summary below is general, so we always contact the council about your address before putting a price in writing.
Re-roofing a house with similar materials does not usually need planning permission in England. Listed buildings and conservation areas may need consent if the covering changes.
Replacing more than a quarter of a roof’s covering counts as renovation under Building Regulations, so the work is notified and the roof insulation may need upgrading. Bats are protected across the UK; if they roost under roof tiles, soffits or fascias, work stops and a licensed ecologist advises before it restarts.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
We look at the job
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a new flat roof so the price reflects your home.
Your fixed price
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Getting ready
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
The work itself
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
What you can expect from us
Flat roofs in Barnes: questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a new flat roof, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
How long does a flat roof last?
A well-installed EPDM or GRP flat roof can last 25 years or more, while torch-on felt systems typically last around 15–25 years, depending on quality and exposure. Lifespan depends on correct falls, good detailing at edges and upstands, and keeping outlets clear. Foot traffic, ponding and poor ventilation shorten it. Annual checks help catch small problems early.
Can you repair my flat roof instead of replacing it?
A flat roof can often be repaired if the damage is limited to a small split, a failed joint or a loose upstand and the rest of the covering is sound. If the deck is soft, the covering is blistered or cracked across the roof, or leaks keep returning, replacement is usually better value. We assess the whole roof and give you an honest recommendation.
How much will a new flat roof cost in Barnes?
As a guide, expect to pay £2,600–£5,800 including VAT for a new flat roof in Barnes. That range is adjusted for London, which runs about 30% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
How long does a flat roof replacement take?
Replacing a typical extension or garage flat roof usually takes one to three days. Stripping and any deck repairs come first, then insulation where agreed, the new membrane and the trims and outlets. GRP needs dry weather and time to cure, and we plan around the forecast. Larger roofs or roofs with many rooflights take longer. We confirm timing with your quote.
Nearby towns
Homes across SW13, SW14, SW15 and TW9 in Barnes are within our coverage, as are those in Chiswick, Putney and Fulham. If you are just outside these areas, ask anyway, because we work right across the UK.