Rear extension steels · South Lanarkshire
Rear extension steels in South Lanarkshire
Calculations, approvals, propping, steel and making good for rear extension steels across South Lanarkshire.
- Free survey visit in South Lanarkshire
- Engineer's calculations arranged
- Building warrant handled for you
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
About our rear extension steels service in South Lanarkshire
Rear extension steels are the beams, columns and frames that let the original back wall of a house be opened up into a new extension. Sized by a structural engineer, they pick up the floor, wall and roof loads that the old wall carried and pass them into bearings or foundations, so the new and old spaces join as one open room.
We carry out rear extension steels throughout South Lanarkshire, for homeowners, landlords and builders who need the structural part done properly. We work in High Blantyre, East Kilbride and Blantyre and the surrounding villages. You get an itemised written quote that shows the calculations, approvals, steel, labour and finishing as separate lines.
What to expect
- The building standards completion certificate for the extension covers the steelwork to the old rear wall. Keep it with the engineer's calculations and drawings, as a buyer's solicitor will expect to see the structural paperwork for the extension.
- When bi-fold or sliding doors sit directly beneath the new steel, the beam has to stay stiff enough not to bind the door panels. The engineer sets a tighter deflection limit, which can mean a deeper or heavier section than strength alone would need.
- During the opening, props stand both inside the house and within the extension footprint. Where props bear on a newly laid slab, the propping plan checks that the slab can take those point loads, using spreaders where needed.
- In older houses the rear wall may be solid brick in lime mortar, with timber lintels and shallow footings beneath. The engineer may ask for trial holes to see what the wall stands on before deciding where the steel will bear.
- A single beam works where solid masonry is left at both ends of the opening. Where the opening runs nearly the full width or the corners are weak, the engineer may use columns or a goalpost frame, which is two posts and a beam bolted together.
How the job runs in South Lanarkshire
Look and measure
We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
Building warrant
A building warrant is applied for from South Lanarkshire Council, and work starts only once the warrant has been granted.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
Guide prices for rear extension steels in South Lanarkshire
As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in South Lanarkshire, based on published UK cost guides adjusted for prices in Scotland (-9%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,300–£6,350 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Steel goalpost frame | £1,800–£5,450 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Side return extension steelwork | £3,200–£7,750 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| Structural calculations for a beam | £230–£680 | Site measure or photos, beam and padstone design and calculations for building standards |
Figures include our approximate regional adjustment for prices in Scotland (-9%) and are rounded. How these figures are worked out.
Building rules for South Lanarkshire
In Scotland, structural alterations need a building warrant under the Building (Scotland) Act 2003, and work must not start until the warrant is granted. For South Lanarkshire, warrants are handled by South Lanarkshire Council's building standards service. When the work is finished, a completion certificate is submitted and has to be accepted by the council.
Scotland has no Party Wall Act. Work affecting a shared wall is governed by your title deeds and the general law, and in flats by the Tenements (Scotland) Act 2004, so it is sensible to agree the work with neighbours in writing before starting.
Rear extension steels by town
Local questions answered
How much do rear extension steels cost in South Lanarkshire?
As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in South Lanarkshire, based on published UK cost guides adjusted for prices in Scotland (-9%). The exact figure depends on the span, what the wall carries, access and the finish, and is fixed in writing once the scope is agreed.
How soon can rear extension steels start in South Lanarkshire?
Start dates depend on the engineer's calculations, the building warrant and any agreement needed with neighbours. We give you a realistic timetable after the survey and keep you updated as each approval comes through.
Do I need a steel beam for my rear extension?
If the original back wall is being opened up into the extension, almost certainly yes. That wall normally carries the first floor and the wall above, so a beam, columns or a goalpost frame takes over the job. A structural engineer confirms exactly what is needed once the opening width and loads are known.
Can I use my own builder for the extension and you for the steels?
Yes. We can supply and fit the steel package while another builder handles the extension shell and finishes. Dates are agreed with them so the rear wall is opened at the right stage, and the engineer's details are shared so levels, padstones and foundations line up.
How wide can a rear extension opening be?
There is no fixed limit, and openings across the full width of a house are common with the right steel. The engineer sizes the beam or frame for the span and the loads above. Wider spans need deeper or heavier steel and possibly columns, which affects headroom and cost.
When does the back wall come out during an extension build?
Usually once the extension walls and roof are up and the new space is weathertight. That keeps the house secure and dry while the opening is formed. The steel goes in, building standards inspects it, and the builder then carries the floors and ceilings through.
Can I stay at home while the work is done in South Lanarkshire?
Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.