Rear extension steels · Renfrewshire
Rear extension steels in Renfrewshire
Rear extension steels across Renfrewshire, designed by a structural engineer and built under a building warrant.
- Price fixed in writing once scope is agreed
- Building warrant arranged
- Temporary works and making good included
- 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 Renfrewshire: how it works
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.
Across Renfrewshire, rear extension steels usually come up when people want more light, a better layout or a way through to a new extension. We can survey in places such as Johnstone, Paisley and Renfrew and the villages around them. Whatever the reason, the beam is sized from calculations and the work is inspected before anything is covered.
Worth knowing before you start
- 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.
- 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.
- Soil stacks, waste pipes, boiler flues and gas meters are often fixed to the back wall. These are moved before the wall opens, and any work on gas pipework must by law be carried out by a Gas Safe registered engineer.
- 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.
- 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 Renfrewshire
Free visit
A short visit to Renfrewshire 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 warrant
A building warrant is applied for from Renfrewshire Council, and work starts only once the warrant has been granted.
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 Renfrewshire?
As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Renfrewshire, 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) |
Figures include our approximate regional adjustment for prices in Scotland (-9%) and are rounded. How these figures are worked out.
Building control and neighbours in Renfrewshire
Scottish rules are stricter on timing than in England: the building warrant must be in place before the wall is touched. We prepare the application with the engineer's calculations and submit it to Renfrewshire Council. The finished work is then certified and a completion certificate submitted for acceptance.
There is no party wall notice system in Scotland. Instead, check your title deeds and, for flats, the tenement management scheme, and talk to neighbours early if the beam bears into a shared wall.
Local questions answered
Which towns in Renfrewshire do you cover?
We cover towns including Paisley, Renfrew, Johnstone and Erskine, plus the villages and smaller towns around them.
Can I stay at home while the work is done in Renfrewshire?
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.
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 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.
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.
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 standards 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.