Rear extension steels · Greater Manchester
Rear extension steels in Greater Manchester
Calculations, approvals, propping, steel and making good for rear extension steels across Greater Manchester.
- Free survey visit in Greater Manchester
- Engineer's calculations arranged
- Building control 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
What rear extension steels involve in Greater Manchester
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.
From the first survey visit to the completion certificate, we take care of rear extension steels across Greater Manchester. Towns we cover include Oldham, Manchester and Bury, among other places in the area. The engineer sizes the steel, we deal with building control, and our team fits and packs the beam before making good.
Worth knowing before you start
- The opening is usually formed once the extension walls and roof are up, so the house stays secure and dry. Leaving it too late can hold up plastering and floor screeding, so the steel date is agreed with the builder early on.
- 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.
- Opening the rear wall is usually the dustiest stage of an extension project. The work face is sheeted off from the rest of the house, and the kitchen is often out of use for a few days while the opening is formed and the steel goes in.
- 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.
- In terraced and semi-detached houses one end of the beam often bears into the party wall. In England and Wales that is notifiable under the Party Wall etc. Act 1996, and the extension's own foundations near the boundary may need notices as well.
What happens, step by step
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 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.
Fit, inspect, finish
The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.
How much should I budget in Greater Manchester?
As a guide, budget £2,400–£6,700 including VAT for opening into a rear extension in Greater Manchester, based on published UK cost guides adjusted for prices in the North West (-4%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,400–£6,700 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Rear wall opening for bi-fold or sliding doors | £2,400–£6,700 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Side return extension steelwork | £3,350–£8,150 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| Structural calculations for a beam | £240–£720 | Site measure or photos, beam and padstone design and calculations for building control |
Figures include our approximate regional adjustment for prices in the North West (-4%) and are rounded. How these figures are worked out.
Approvals in Greater Manchester
Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.
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.
Rear extension steels by town
- Manchester
- Oldham
- Wigan
- Bolton
- Stockport
- Salford
- Rochdale
- Sale
- Bury
- Altrincham
- Middleton
- Ashton-under-Lyne
- Leigh
- Stretford
- Urmston
- Chadderton
- Eccles
- Tyldesley
- Hyde
- Walkden
- Prestwich
- Radcliffe
- Cheadle Hulme
- Heywood
- Denton
- Stalybridge
- Ashton in Makerfield
- Westhoughton
- Farnworth
- Saddleworth
- Hindley
- Golborne
- Droylsden
- Whitefield
- Swinton
- Royton
- Atherton
- Dukinfield
- Failsworth
- Hazel Grove
Rear extension steels in Greater Manchester: your questions
Do I need a party wall agreement for rear extension steels in Greater Manchester?
Yes, if the beam bears into a shared wall: the Party Wall etc. Act 1996 applies in England and Wales, and a party structure notice must be served at least two months before that work starts. We arrange it through a party wall surveyor.
Which towns in Greater Manchester do you cover?
We cover towns including Manchester, Oldham, Wigan and Bolton, plus the villages and smaller towns around them.
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 control inspects it, and the builder then carries the floors and ceilings through.
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.
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.
Will my kitchen be out of action while the rear wall is opened?
For a few days, usually. The kitchen often sits against the rear wall, so units, sinks or appliances near the opening may need disconnecting while the wall is propped and removed. The work area is sheeted off and the rest of the house stays in use.
What happens at the survey visit in Greater Manchester?
We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.