What Does Structural Steelwork Cost?
Quick Answer
RSJ installed £450–£1,500 by span. Whole knock-through £1,800–£4,500
Beam supply, labour, props and padstones for a typical domestic opening; engineer and building control fees on top. Guide prices from published 2026 UK cost guides, not quotes
Important: all structural steelwork must be designed by a qualified structural engineer and approved under Building Regulations before installation. Nothing on this page sizes a beam.
RSJ Cost by Span, Supplied and Installed (2026 UK)
MyJobQuote’s July 2026 RSJ guide prices the beam work itself (supply plus installation labour, before professional fees) by span:
| Beam span | Supply only | Supplied and installed |
|---|---|---|
| 1m | £50–£100 | £450–£570 |
| 2m | £100–£200 | £650–£840 |
| 3m | £150–£300 | £800–£1,100 |
| 4m | £200–£400 | £900–£1,280 |
| 5m | £250–£500 | £1,150–£1,500 |
Supply pricing works out at £50–£100 per metre across guides, and a typical installation takes 1–2 days at builder day rates of £250–£400. Estimate the steel itself with our steelwork weight calculator, and the bearing and temporary-support details with the RSJ installation calculator.
Fees and Extras on Top
| Item | Guide price | Notes |
|---|---|---|
| Structural engineer, single beam design | £250–£700 | Guides disagree: MyJobQuote quotes £300–£500 (basic calculations from £250); BookaBuilderUK prices simple beam design at £250–£400 and more complex alterations at £400–£700, with full structural reports for extensions from £700 |
| Building control | £200–£500 | Set by each council or approved inspector; removing a load-bearing wall is always notifiable |
| Acro props, needles and padstones | £100–£200 | Temporary support hire plus concrete bearing pads |
| Steel delivery | £50–£150 | Depends on beam size and distance from the stockholder |
| Skip hire | £200–£300 | For the demolished masonry on a knock-through |
| Making good (plastering) | £20–£30 per m² | Boxing in, fire-rated plasterboard and skim; decoration extra |
Whole-Project Totals: the Guides Disagree
MyJobQuote’s overall band for the beam work is £800–£2,500 with a national average around £1,400, while BookaBuilderUK’s 2026 figure for a complete straightforward knock-through (beam, wall removal, waste and making good) is £1,800–£4,500, climbing beyond £7,000 for complex structural alterations. The difference is scope: once the wall below comes out, waste, plastering and decoration join the bill. Treat £1,800–£4,500 as the realistic all-in range for a single-beam wall removal, and multi-beam open-plan conversions at £2,500–£5,500+ (MyJobQuote’s complex-project band).
What Affects the Price
- Span and section: longer, heavier beams cost more to buy and need more labour to place
- Storey and access: ground-floor openings with clear access are cheapest; upper floors and tight terraces cost more
- Wall type: cutting into a 215mm solid masonry wall is slower than a 100mm skin
- Steel weight: beams over roughly 100kg need more hands or lifting kit; check with the steelwork weight calculator
- Fire protection: exposed steel must achieve the required fire resistance, usually via fire-rated plasterboard within making good
- Connections: bolted splices, cranked beams and columns move a job into the complex band; size columns with the steel column calculator
The Installation Process
- Structural engineer designs the beam and bearings
- Building control application approved
- Temporary support installed (Acrow props and needles)
- Padstone pockets formed and concrete padstones installed
- Beam lifted, positioned, packed and wedged to level
- Wall below removed (if opening up)
- Fire protection applied, then temporary support removed once set
Important Notes
- All figures are guide prices from published 2025–2026 UK cost guides, not quotes: get at least three itemised quotes
- Never remove a load-bearing wall without an engineer’s design and building control approval; retrospective regularisation costs far more
- Ask whether the quote includes making good, waste and fire protection; those are the usual gaps
Figures cross-checked against published UK cost guides July 2026. Last updated: July 2026