
Rear extension steels · West Yorkshire
Rear extension steels in West Yorkshire
Rear extension steels across West Yorkshire, designed by a structural engineer and signed off by building control.
- Itemised written quote
- Beam sized by a structural engineer
- Covering West Yorkshire and nearby
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Planning rear extension steels in West Yorkshire
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.
Homes across West Yorkshire range from Victorian terraces to post-war semis and newer estates, and rear extension steels look different in each. We work in Keighley, Castleford and Leeds and the surrounding villages. We plan the steel, the temporary support and the approvals around the building, then fix the price in writing once the scope is agreed.
Key points for your project
- Where the extension ceiling and the house ceiling should run through at one level, the steel may need setting higher into the floor zone or tying in with the extension roof structure. That choice changes the steel design, so it is settled before calculations.
- The steelwork forms part of the extension's building regulations approval, and the engineer's calculations go in with it. Planning for the extension itself is separate; many rear extensions to houses in England fall within permitted development, subject to size limits and conditions.
- 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.
- Two-storey rear extensions add a second level of loads to think about. Steels at first-floor level may carry the existing rear wall of the bedrooms or tie the new roof into the old one, so the engineer looks at both floors together.
- The building control 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.
How the job runs in West Yorkshire
Free visit
A short visit to West Yorkshire to see the job, agree what you want and check the bearings, floors and services that affect the design.
Calculations
The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.
Building control
We submit a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.
Steel in, made good
On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.
What do rear extension steels cost in West Yorkshire?
As a guide, budget £2,400–£6,650 including VAT for opening into a rear extension in West Yorkshire, based on published UK cost guides adjusted for prices in Yorkshire and the Humber (-5%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,400–£6,650 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Structural calculations for a beam | £240–£710 | Site measure or photos, beam and padstone design and calculations for building control |
| Steel goalpost frame | £1,900–£5,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Side return extension steelwork | £3,300–£8,100 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
Figures include our approximate regional adjustment for prices in Yorkshire and the Humber (-5%) and are rounded. How these figures are worked out.
Approvals in West Yorkshire
For West Yorkshire, building control is provided by the local council's building control team, or by a registered building control approver if preferred. We send them the engineer's calculations with a building notice or full plans application and book the inspections. Work done without approval can cause problems at sale and is far dearer to put right later.
Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.
Local questions answered
How soon can rear extension steels start in West Yorkshire?
Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.
Can I stay at home while the work is done in West Yorkshire?
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.
Is the steel included in the extension's building regulations?
Yes. The steelwork is part of the extension, so the engineer's calculations go to building control with the extension application and the steel is inspected before it is covered. The completion certificate issued for the extension then covers the structural work to the rear wall.
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.
What is a goalpost frame in an extension?
A goalpost frame is two steel columns with a beam across the top, bolted together and standing on their own foundations. It is used where the opening is so wide that little masonry is left to bear on, or where the existing corners cannot take the load. The engineer decides whether one is needed.
Do I need a party wall agreement for extension steels?
In England and Wales, if a beam bears into a wall shared with a neighbour, or the extension foundations are dug close to theirs, notice under the Party Wall etc. Act 1996 is usually required. We can arrange the notices through a party wall surveyor. There is no equivalent legislation in Scotland or Northern Ireland.
How much do rear extension steels cost in West Yorkshire?
As a guide, budget £2,400–£6,650 including VAT for opening into a rear extension in West Yorkshire, based on published UK cost guides adjusted for prices in Yorkshire and the Humber (-5%). 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.