Croydon · London
Underpinning in Croydon
South London borough with strong appetite for lofts, extensions and garage conversions.
Croydon
Underpinning specialists across Croydon.
We deliver underpinning projects across the full Croydon postcode set — CR0, CR2, CR5, CR7, CR8, CR9, SE25. South London borough with strong appetite for lofts, extensions and garage conversions.
Underpinning is the process of deepening or strengthening an existing foundation by excavating below it in controlled sections and replacing with new concrete bearing onto stronger sub-strata. London's clay sub-soil, shallow Victorian footings and proximity of mature trees mean underpinning is one of the most common London structural repairs. Builderr undertakes underpinning for three scenarios: subsidence repair (correcting a foundation that has moved), basement conversion (creating new headroom below the existing floor) and structural enhancement (preparing for double-storey or larger extensions where existing footings are inadequate).
Every Croydon 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
Underpinning cost in Croydon 2026.
| Configuration | Cost range | Timeline |
|---|---|---|
| Localised subsidence repair (3–5m run) | £8,000–£18,000 | 3–5 wks |
| Full perimeter underpin for basement conversion (per linear metre) | £1,200–£2,200 | 6–10 wks |
| Underpin for double-storey extension footings | £12,000–£28,000 | 4–6 wks |
| Mini-piled underpinning (poor sub-strata) | £1,800–£2,800 | 5–8 wks |
Local advantage
Eight years of underpinning work in Croydon.
Familiarity with Croydon's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 7 postcodes the borough covers.
Recent Croydon work
Underpinning 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 £400–£900 on a underpinning in Croydon.
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 £2,000.
FAQ
Underpinning in Croydon.
How much does a underpinning cost in Croydon?+
Underpinning projects in Croydon typically cost £1,000–£3,000. Croydon sits across postcodes CR0, CR2, CR5, CR7; local rates align with the wider London market.
Do underpinnings in Croydon need planning permission?+
South London borough with strong appetite for lofts, extensions and garage conversions. 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 Croydon postcodes?+
Yes — we deliver underpinning projects across all Croydon postcodes including CR0, CR2, CR5, CR7, CR8, CR9, SE25.
How much does underpinning cost in London?+
Underpinning in London costs £1,200–£2,800 per linear metre depending on depth, method and ground conditions. A typical subsidence repair (3–5m affected) runs £8,000–£18,000. A full basement perimeter underpin (25–40m) runs £40,000–£90,000+. Mini-piled underpinning (where sub-strata is poor) is more expensive than mass concrete bay.
How long does underpinning take?+
3–10 weeks on site depending on linear extent. Localised subsidence repair (3–5m) 3–5 weeks. Full basement perimeter underpin 6–10 weeks. Work is sequenced bay-by-bay with curing time between adjacent bays, so the schedule cannot be compressed by adding more labour.
Get a Croydon underpinning quote.
Senior consultant call within one business hour. Fixed-scope quote for your Croydon project — no provisional sums.
Other types in Croydon
Explore other build types in Croydon.
Underpinning across London