Removing a Load-Bearing Wall: Cost, RSJ Prices and Regs (2026)
Removing a load-bearing wall costs £1,800-£7,500 in 2026, including the RSJ, engineer's calculations, and Building Control. See the cost breakdown and the regs your quote must cover.
Knocking two rooms into one is one of the most popular ways to open up a home, but a load-bearing wall is holding the house up, so it cannot just come down. The cost reflects three things most people do not budget for: a structural engineer, a steel beam, and Building Control. Here is what it actually costs in 2026 and what your quote must include.
Quick cost summary
| Job | Typical cost |
|---|---|
| Structural engineer's calculations | £300-£700 |
| Steel beam (RSJ) supplied and installed | £1,800-£2,200 |
| Building Control application and inspections | £300-£900 |
| Making good (plaster, floor, decoration) | £500-£2,000 |
| Typical total, single opening | £1,800-£4,500 |
| Wide opening or two-storey wall | £4,500-£7,500+ |
Prices based on UK trade averages and MyBuildAlly quote analysis, mid-2026. A bigger span, a heavier beam, or temporary propping of upper floors pushes costs up.
Why it is not just "knock the wall down"
A load-bearing wall carries the weight of the floor or roof above it. Take it away and that load has to go somewhere, which is the job of the steel beam (RSJ) that replaces it. Getting that right is engineering, not guesswork.
Removing a load-bearing wall is structural work. It needs a structural engineer to calculate the beam size and the bearings, and it needs Building Control approval and a final inspection. This applies even though internal work like this usually needs no planning permission. The engineer's fee and the Building Control fee are part of the real cost, not optional extras.
The lines a quote must include
A complete load-bearing wall quote should show, separately:
- The structural engineer's fee (£300-£700) for the calculations and beam specification
- The steel beam, its size, and the padstones it bears on
- Propping to support the structure while the wall comes out
- Building Control application and inspection fees
- Making good: re-plastering, flooring across the old wall line, and decoration
- Any services (electrics, radiators, pipes) in the wall that must be moved
Our structural engineer cost guide covers the engineer's part, and how to check structural steelwork covers inspecting the installed beam.
The two red flags
First, a quote with no structural engineer's fee and no Building Control line. If neither is in the quote, either someone is planning to skip them (dangerous and unsellable) or they are hidden and will reappear as extras. Second, a beam specified before any engineer has done calculations. The beam size depends on the span and the load; nobody can correctly quote the steel without the calcs.
A wall removed without engineer's calculations and Building Control sign-off is a serious problem. When you sell, the buyer's solicitor will ask for the completion certificate, and you will not have one.
What about services in the wall?
Walls often hide electrics, radiator pipes, or even a soil pipe. Moving these is extra and is easy to leave off a quote. If there is a radiator, a socket, or a switch on the wall coming out, ask where it is going and whether that is priced.
Check your quote
This job sits exactly where cost and compliance meet, which is where incomplete quotes do the most damage. Upload your quote and we check that the engineer's fee, the beam, Building Control, and making good are all actually in there, and flag it when a low price is low because the structural and compliance work has been left out. It takes under a minute.
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