Barnet · London
Wraparound Extension in Barnet
North London borough with large 1930s semis ideal for loft conversions and wraparound extensions.
Barnet
Wraparound Extension specialists across Barnet.
We deliver wraparound extension projects across the full Barnet postcode set — N2, N3, N11, N12, N20, NW4, NW7, NW11, EN4, EN5. North London borough with large 1930s semis ideal for loft conversions and wraparound extensions.
A wraparound extension combines a side return and rear extension into a single L-shaped footprint. It's the largest possible single-storey ground floor on a Victorian or Edwardian terrace and turns the entire ground floor into an open-plan family hub — kitchen, dining and living rooms all flowing into each other with full garden views.
Every Barnet project includes a free desk-based planning assessment before we quote. We know the local planning officers, party wall surveyors and approved inspectors by name.
Costs
Wraparound Extension cost in Barnet 2026.
| Configuration | Cost range | Timeline |
|---|---|---|
| Standard wraparound (3m side + 3m rear) | £90,000–£125,000 | 14–17 wks |
| Larger wraparound (3m side + 5m rear) | £115,000–£155,000 | 16–19 wks |
| Premium wraparound with structural glass | £145,000–£200,000 | 18–22 wks |
Local advantage
Eight years of wraparound extension work in Barnet.
Familiarity with Barnet's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 10 postcodes the borough covers.
Recent Barnet work
Wraparound Extension examples.
Builderr vs other London builders.
The construction industry has a wide distribution of operators. Here's what changes between a directly-employed, fixed-scope outfit and the alternatives.
| Criterion | Builderr | Typical London builder | Cowboy outfit |
|---|---|---|---|
| Labour model | Directly employed team (PAYE) | Mixed subcontract gangs | Day-rate cash labour |
| Pricing | Fixed-scope itemised quote | Estimate + provisional sums | Verbal price + variations |
| Design & engineering | In-house architect + SE | Outsourced, separate billing | Builder draws on the back of an envelope |
| Planning + LDC handled | Yes — included in price | Often charged extra | Builder asks you to apply |
| Party wall surveyors | Instructed by us | Your responsibility | Skipped (illegal) |
| Building control | Plans + site inspections booked by us | Building Notice route | Not registered |
| Project management | Dedicated PM, weekly photo updates | Foreman doubles up | Owner-manager juggles 5 jobs |
| Payment schedule | Stage payments against signed-off milestones | Weekly invoices | Cash up front |
| Insurance | £10M PL + 10yr structural warranty | £2–5M PL only | No documented cover |
| Snags at handover | <3 typical | 20–30 typical | Walk-off mid-job common |
| Variation creep | 0% — fixed scope | +15–25% over original quote | +40%+ regularly |
Save £29,000–£65,250 on a wraparound extension in Barnet.
Industry data (FMB, RICS, Which? Trusted Trader 2024) shows the average London construction project overruns by 18–22% on cost and 25–35% on time. Fixed-scope contracts with a single accountable team eliminate that variance. The savings above assume a typical project at £145,000.
FAQ
Wraparound Extension in Barnet.
How much does a wraparound extension cost in Barnet?+
Wraparound Extension projects in Barnet typically cost £90,000–£200,000. Barnet sits across postcodes N2, N3, N11, N12; local rates align with the wider London market.
Do wraparound extensions in Barnet need planning permission?+
North London borough with large 1930s semis ideal for loft conversions and wraparound extensions. We carry out a free desk-based planning assessment for your specific address before quoting, identifying whether permitted development, prior approval, or full planning applies.
Do you work across all Barnet postcodes?+
Yes — we deliver wraparound extension projects across all Barnet postcodes including N2, N3, N11, N12, N20, NW4, NW7, NW11, EN4, EN5.
How much does a wraparound extension cost in London?+
Typically £90,000–£200,000 depending on size, spec and glazing. Most projects sit in the £110–150k range fully fitted.
Do I need planning permission for a wraparound?+
Almost always yes — wraparounds usually exceed PD limits in volume and depth.
Get a Barnet wraparound extension quote.
Senior consultant call within one business hour. Fixed-scope quote for your Barnet project — no provisional sums.

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