How much does a steel beam (RSJ) cost to install in the UK?
A steel beam installation costs £2,000 on average in the UK. Most jobs fall between £1,200 and £6,000 supplied and fitted. Beam size and opening: Single beam £1,200 to £2,000; Knock-through £2,000 to £3,500; Wide opening or multiple beams £3,500 to £6,000. Prices reviewed June 2026.
Installing a steel beam (RSJ) usually costs between £1,200 and £6,000 in the UK, with most people paying around £2,000 for a single beam supplied and fitted, including propping and making good. The price depends mainly on the span and weight of the beam and how much wall is removed. The structural engineer's calculations are charged separately.
Steel beam (RSJ) cost calculator
Use the calculator to price your steel beam installation in 2026. Adjust the options and area for a UK cost range. Nothing is sent anywhere.
Steel beam (RSJ) cost breakdown
Typical steel beam installation costs, by option:
| Beam size and opening | Typical UK cost |
|---|---|
| Single beam, small opening | £1,200 to £2,000 |
| Knock-through, one large beam | £2,000 to £3,500 |
| Wide opening or multiple beams | £3,500 to £6,000 |
What's included in the price?
Typical steel beam installation prices include:
- Supplying the steel beam (RSJ) cut to the right size
- Acrow props and strongboys to hold the structure while you work
- Removing the load-bearing wall or forming the new opening
- Fitting the beam onto padstones or spreader plates
- Bearing, bolting and fire-protecting the steel
- Making good the plaster around the new opening
What changes the price?
The things that move steel beam installation prices most:
The span and weight of the beam, which sets its size
Whether one beam or a goalpost or multiple beams are needed
How much wall is removed and how much making good is involved
Access, and whether the work is upstairs or at ground level
Your region
How the price is built up
The quote covers the steel supplied cut to size, temporary propping, removing the wall, forming the bearings and padstones, seating and fixing the beam, fire protection and plastering the reveals. Bigger spans need heavier steel and more people to lift it, and the engineer's calculations and building control fees are usually charged on top. The steel itself is a small part of the bill; a standard RSJ costs roughly £150 to £500. Most of the price is labour, covering the propping, cutting out the wall, lifting the beam in, padstones and making good.
Ways to keep the cost down
- Get the structural engineer's calculations done first so every builder quotes on the same spec
- Keep the opening to a standard width to avoid a heavier, pricier beam
- Do your own decorating once the plaster has been made good
Does where you live change the cost?
In London, a steel beam installation typically costs around £2,600 supplied and fitted, about 30% above the UK average of £2,000. In the North, Scotland and Wales the guide figure is nearer £1,800.
| Region | From | Typical | Up to |
|---|---|---|---|
| Midlands / East (UK average) | £1,200 | £2,000 | £6,000 |
| London | £1,600 | £2,600 | £7,800 |
| South East / South West | £1,400 | £2,300 | £6,900 |
| North / Scotland / Wales | £1,100 | £1,800 | £5,500 |
Guide prices supplied and fitted, scaled with the same regional multipliers as the calculator. Not quotes.
Steel beam (RSJ) cost in major UK cities
| City | From | Typical | Up to |
|---|---|---|---|
| Belfast | £1,000 | £1,700 | £5,100 |
| Birmingham | £1,200 | £2,000 | £5,900 |
| Bristol | £1,300 | £2,200 | £6,600 |
| Cardiff | £1,100 | £1,900 | £5,600 |
| Edinburgh | £1,200 | £2,000 | £5,900 |
| Glasgow | £1,100 | £1,800 | £5,400 |
| Leeds | £1,100 | £1,900 | £5,600 |
| Liverpool | £1,100 | £1,800 | £5,500 |
| London | £1,600 | £2,600 | £7,800 |
| Manchester | £1,200 | £1,900 | £5,800 |
| Newcastle | £1,100 | £1,800 | £5,400 |
| Sheffield | £1,100 | £1,800 | £5,500 |
City guide estimates, scaled by local labour costs. Indicative averages for steel beam installation, not quotes.
The South East and London are the priciest, often 20 to 30 percent above the North, Wales and Scotland. Steel prices are fairly similar across the country, so it is mostly the labour rate that drives the gap.
Common questions
How much does it cost to install a steel beam (RSJ) in 2026?
Around £1,200 to £6,000 supplied and fitted, with most single beams for a load-bearing wall costing about £2,000. Wider knock-throughs and jobs needing more than one beam sit at the higher end.
What changes the price of a steel beam?
Mainly the span and weight, as a longer or more heavily loaded opening needs a bigger, heavier beam. More wall removed, working upstairs, tight access and needing a goalpost or two beams all push the cost up.
Do I really need a steel beam and an engineer?
If the wall is load-bearing, yes. You need a structural engineer's calculations (usually £300 to £600) and building control sign-off before work starts. It is not optional and skipping it can cause problems when you sell.
Can I fit a steel beam myself?
It is not advised. Getting the propping wrong on a load-bearing wall is dangerous, and building control will want the beam sized and installed to the engineer's calculations. This is a job for an experienced builder.
How long does fitting a steel beam take?
A single beam is typically 2 to 4 days on site, and a larger opening 4 to 7 days once the props, beam and plastering are done. The calculations and building control notice add a week or two beforehand.
Does a steel beam need anything doing to it afterwards?
Yes, and it is the part people do not budget for. Structural steel has to reach a minimum period of fire resistance under Approved Document B, typically 30 minutes in an ordinary two-storey house, so the beam cannot simply be left as bare steel. In practice that means boxing it in with fire-rated plasterboard, or two layers of standard board, and a plaster skim. If you want the beam left exposed for the look that is possible, but it needs an intumescent coating system instead and that costs more than boarding it. Either way your building control inspector confirms what is acceptable in your particular case, so settle it before the plasterer arrives rather than after. Past that, a beam inside a dry house needs nothing at all and will outlast everything around it. The only real long-term risk is corrosion where steel gets wet, so a beam in an external wall or over an exposed opening wants its paint system kept intact.
Is there a cheaper alternative to a steel beam?
For a small non-load-bearing opening a timber lintel may do, which is far cheaper. For any real load a steel beam is usually the sensible option, but keeping the opening to a standard width avoids a heavier, more expensive beam.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing.