Barking and Dagenham · London
Rear Extension in Barking and Dagenham
East London borough with a strong stock of post-war semis suited to rear and side extensions.
Barking and Dagenham
Rear Extension specialists across Barking and Dagenham.
We deliver rear extension projects across the full Barking and Dagenham postcode set — IG11, RM8, RM9, RM10. East London borough with a strong stock of post-war semis suited to rear and side extensions.
A rear extension projects from the back of the house into the garden, creating open-plan living, a new kitchen or a family room. Single-storey rears can extend up to 6 metres on detached homes and 8m by prior approval under the Larger Home Extension scheme. They suit terraces, semis and detached houses across London and remain the most popular extension type by volume.
Every Barking and Dagenham 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
Rear Extension cost in Barking and Dagenham 2026.
| Configuration | Cost range | Timeline |
|---|---|---|
| Single-storey rear (3m deep) | £50,000–£75,000 | 10–12 wks |
| Single-storey rear (5–6m deep) | £70,000–£100,000 | 12–14 wks |
| Rear + kitchen install | £85,000–£120,000 | 13–16 wks |
| Premium rear (structural glass, Crittall) | £105,000–£130,000 | 14–18 wks |
Local advantage
Eight years of rear extension work in Barking and Dagenham.
Familiarity with Barking and Dagenham's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 4 postcodes the borough covers.
Recent Barking and Dagenham work
Rear 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 £18,000–£40,500 on a rear extension in Barking and Dagenham.
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 £90,000.
FAQ
Rear Extension in Barking and Dagenham.
How much does a rear extension cost in Barking and Dagenham?+
Rear Extension projects in Barking and Dagenham typically cost £50,000–£130,000. Barking and Dagenham sits across postcodes IG11, RM8, RM9, RM10; local rates align with the wider London market.
Do rear extensions in Barking and Dagenham need planning permission?+
East London borough with a strong stock of post-war semis suited to rear and side 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 Barking and Dagenham postcodes?+
Yes — we deliver rear extension projects across all Barking and Dagenham postcodes including IG11, RM8, RM9, RM10.
How much does a rear extension cost in London?+
Typically £50,000–£130,000 depending on depth, glazing spec, kitchen inclusion and any structural complications.
Do I need planning permission?+
3m deep and under is permitted development. 3m–6m on a terrace or semi requires prior approval under the Larger Home Extension scheme. Beyond that or in conservation areas, full planning.
Get a Barking and Dagenham rear extension quote.
Senior consultant call within one business hour. Fixed-scope quote for your Barking and Dagenham project — no provisional sums.
Other types in Barking and Dagenham
Explore other build types in Barking and Dagenham.
Rear Extension across London