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 Harrow 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
- HA1, HA2, HA3, HA5 and HA7
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
What should you budget for a new flat roof in Harrow?
Every figure below is a guide for a new flat roof in Harrow, inclusive of VAT. Regional pricing for London works out about 30% above the national guide, and the overall span is £2,600–£5,800. The survey costs you nothing, and after it we commit to a firm price for your specification in writing.
| Type of job | What it usually involves | Guide in Harrow |
|---|---|---|
| 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:
- Roof area and access to the roof
- Covering system: EPDM, GRP or torch-on felt
- Condition of the deck and joists underneath
- Number of rooflights, pipes and upstands to detail
What’s included?
- Survey of the covering, deck, falls, upstands and drainage
- Replacement of rotten or soft deck boards
- Insulation upgrade to a warm roof build-up where agreed
- New EPDM, GRP or torch-on felt membrane laid to falls
- Upstands, flashings and drip edges finished neatly
- New trims, outlets and gutter connections
Local housing and a new flat roof
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 variety is why a guide price for a new flat roof in Harrow is only a starting point; the survey shows what your particular property needs.
Do you need permission in Harrow?
Harrow is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
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
Free site survey
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a new flat roof.
Written quote
After the survey we send a quote for a new flat roof that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Dates and permissions
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.
Finish and handover
Our trades complete a new flat roof while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Working with SK Home Improvements
Questions about a new flat roof in Harrow
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.
Do I need planning permission in Harrow?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Harrow is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
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.
Also covering areas around Harrow
Whether you're in the centre of Harrow or on its outskirts, HA1, HA2, HA3 and HA5 addresses are covered. We extend the same service, and the same fixed-price approach, to Wealdstone, Brent and Wembley.