Cost of structural repairs in London
Structural repair costs range from £100 to fill a cosmetic crack to £60,000+ for severe subsidence requiring full underpinning. The most important thing to understand before spending anything is the cause. Treating the symptom without fixing the cause is expensive and often makes things worse.
Important
All figures below are approximate London market rates as of 2025–2026. Actual costs depend on the contractor, access, specification, and the scope of works as defined by your structural engineer’s report. Never commission structural repair work without a professional report establishing the cause.
Cost reference table
| Repair type | Low | High | Notes |
|---|---|---|---|
| Hairline/cosmetic crack repair | £100 | £500 | Fill, sand, repaint. DIY possible. |
| Internal crack repair (moderate) | £300 | £1,500 | Includes hack back, reinforce, replaster, redecorate. |
| External crack repointing | £400 | £2,000 | Per elevation. Depends on height and extent. |
| Crack monitoring (tell-tales) | £50 | £200 | Installation only. Review after 12 months. |
| Drain CCTV survey | £150 | £400 | Often recommended when drainage is suspect cause. |
| Non-loadbearing wall removal | £500 | £2,000 | Includes making good, plastering, decoration. |
| Loadbearing wall removal (RSJ beam) | £2,500 | £8,000 | Includes structural engineer calcs, RSJ, padstones, making good. |
| Tree removal (cause of subsidence) | £500 | £5,000 | Varies by size and access. Note: may trigger subsidence reversal (heave) risk. |
| Drain repair/replacement | £1,000 | £6,000 | Depends on depth, length, and access. |
| Foundation strengthening (localised) | £3,000 | £10,000 | Resin injection or limited underpinning of isolated area. |
| Underpinning (mass concrete) | £1,000 | £1,500 | Per linear metre of wall. A typical terraced house might need 5–20m. |
| Underpinning (typical semi-detached, partial) | £8,000 | £25,000 | Depends on extent of movement and soil conditions. |
| Underpinning (severe subsidence, full property) | £20,000 | £60,000+ | Worst-case scenario. May require temporary decant. |
| Resin injection (alternative to underpinning) | £5,000 | £20,000 | Less invasive. Suitable for certain soil types. Less commonly used. |
Why you need a report before commissioning repairs
The most common and costly mistake homeowners make is commissioning cosmetic crack repairs without investigating the cause. If cracks are caused by active foundation movement, filling them will temporarily hide the problem. The movement continues, cracks reappear (often wider), and you’ve wasted money masking a worsening condition.
A structural engineer’s report tells you whether the cause is active or historical, whether the movement is progressive or stable, what remedial works are needed, and in what order to carry them out. That is what stops you spending money on the wrong thing.
Using repair costs in price negotiation
If you’re buying and a structural survey turns up defects, use the repair cost estimate in the report as your basis for renegotiating the price. A vendor who knows the issues are professionally documented will usually negotiate rather than lose the sale.
A pre-purchase structural survey that identifies £15,000 of underpinning work is a £700 spend that saves you £14,300, or gives you the evidence to walk away from a problematic property before exchange.