Structural work · Updated August 2026
RSJ Cost UK 2026: Steel Beams Supplied & Installed
A standard RSJ costs £1,200–£2,500 installed. Removing a load-bearing wall with a steel beam typically runs £1,750–£4,000 all-in, plus £250–£750 for structural engineer calculations and £150–£350 building control.
RSJ & steel beam cost by job — 2026
Supplied and installed, including temporary propping, for a typical two-storey house.
| Job | Typical cost | Timescale | Notes |
|---|---|---|---|
| RSJ supply only (per beam) | £150–£450 | — | Size and span dependent |
| Standard RSJ installed (door-width opening) | £1,200–£2,500 | 1–2 days | The common single-beam job |
| Load-bearing wall removal + beam | £1,750–£4,000 | 2–4 days | Props, beam, padstones, making good |
| Structural engineer calculations | £250–£750 | 1–2 weeks | Required for building control |
| Building control application | £150–£350 | — | A completion certificate protects resale |
Indicative 2026 UK prices, compiled from published installer pricing (Checkatrade, MyJobQuote, MyBuilder and BookaBuilder cost guides, August 2026). BestBuilders has no quote history in this category yet, so treat these as a budgeting guide and confirm against three written quotes.
What changes the cost
| Cost factor | Typical impact | Why it matters |
|---|---|---|
| Span and beam size | £300–£1,500 | A longer opening needs a heavier beam and more men to lift it |
| Engineer's design | £250–£750 | No reputable builder installs without calculations - budget it, don't fight it |
| Temporary works | £150–£500 | Acrow props and strongboys both sides while the wall comes out |
| Making good | £300–£900 | Plastering, boxing-in and decorating after the steel is in |
| Access and floor level | ±£200–£600 | Steels into a first floor or tight terrace cost more to handle |
RSJ installation cost by UK region — 2026
Modelled from regional labour rates rather than measured in this category — materials cost much the same everywhere, the labour does not.
| Region | Typical cost | vs UK average |
|---|---|---|
| London | £2,200–£5,200 | +25–30% |
| South East | £2,000–£4,800 | +15–20% |
| South West | £1,850–£4,200 | +5% |
| Midlands | £1,750–£4,000 | baseline |
| North England | £1,600–£3,800 | −5–10% |
| Scotland | £1,600–£3,600 | −10% |
| Wales | £1,600–£3,600 | −10% |
| Northern Ireland | £1,500–£3,400 | −15% |
Getting it priced properly
1. Engineer first, builder second
Get the structural calculations done before quotes - builders then price the same specified beam, and quotes become comparable.
2. Building control is not optional
A load-bearing alteration without sign-off surfaces at resale. The certificate costs less than the retrospective application.
3. Ask what making good includes
The steel is half the job. Confirm plastering, padstones and decorating are in the quote, not extras.
What this costs at a glance
The same table, drawn.
RSJ & steel beams — frequently asked questions
Typically £1,750–£4,000 in 2026 including the RSJ, temporary props, padstones and making good - plus £250–£750 for structural engineer calculations and a building control fee.
Yes. Building control requires calculations proving the beam carries the load, and no reputable builder will install without them. Expect £250–£750 for a standard domestic opening.
Yes - any structural alteration needs building control sign-off. The completion certificate is what your buyer's solicitor asks for when you sell.
A straightforward door-width opening is one to two days; a full load-bearing wall removal with making good typically runs two to four days.
Related cost guides
When steel beats blockwork on an extension.
Conversions priced - openings and steels included.
Full refits priced by size and spec.
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Reviewed by the BestBuilders editorial team · Last updated: 18 August 2026 · Next scheduled review: November 2026 · See our editorial standards.