
Rear extension steels · Salisbury
Rear extension steels in Salisbury
Rear extension steels for homes in SP1, SP2, designed by a structural engineer.
- Survey, design and installation in one
- Covering SP1, SP2
- Inspected before it is covered
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Rear extension steels in Salisbury: how it works
Our rear extension steels service in Salisbury covers everything from the first visit to the completion paperwork. The wider Wiltshire area is covered as well. Postcode districts we cover here include SP1 and SP2.
Building a rear extension is only half of the open-plan result. The original back wall still holds up the first floor and the rear wall of the bedrooms above, so opening it needs steel. Depending on the width and what is left to bear on, that could be a single beam on padstones, a beam on columns, or a full goalpost frame.
What to expect
- 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.
- 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.
- 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 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.
- 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.
From survey to sign-off in Salisbury
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 Wiltshire Council, 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.
Guide prices for rear extension steels in Salisbury
As a guide, budget £2,600–£7,200 including VAT for opening into a rear extension in Salisbury, based on published UK cost guides adjusted for prices in the South West (+3%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,600–£7,200 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Steel goalpost frame | £2,050–£6,200 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Structural calculations for a beam | £260–£770 | Site measure or photos, beam and padstone design and calculations for building control |
| Side return extension steelwork | £3,600–£8,750 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
Figures include our approximate regional adjustment for prices in the South West (+3%) and are rounded. How these figures are worked out.
Building rules for Salisbury
Structural openings in English homes need building regulations approval before work starts. Wiltshire Council 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.
If the beam bears into a wall you share with a neighbour, the Party Wall etc. Act 1996 applies, and a party structure notice must be served at least two months before that work starts. We arrange this through a party wall surveyor.
Rear extension steels near Salisbury
- Andover 16.4 mi
- Totton 16.9 mi
- Southampton 20.5 mi
- Eastleigh 20.6 mi
- Winchester 20.7 mi
- New Milton 22.4 mi
Local questions answered
Do you also work near Salisbury?
Yes. We also cover nearby towns including Andover, Totton, Southampton and Eastleigh.
How much do rear extension steels cost in Salisbury?
As a guide, budget £2,600–£7,200 including VAT for opening into a rear extension in Salisbury, based on published UK cost guides adjusted for prices in the South West (+3%). 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 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.
Can I have a flat ceiling between the house and the extension?
Often, yes, but it depends on the floor depth above and the loads involved. The steel can sometimes be set up into the floor zone so the ceiling runs through level, which usually means more work to the joists. This needs deciding before the engineer designs the steel.
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.
Do I need a party wall agreement for rear extension steels in Salisbury?
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.