Rear extension steels · Dumbarton
Rear extension steels in Dumbarton
Rear extension steels for homes in G82, designed by a structural engineer.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Dumbarton 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 Dumbarton
For homes in Dumbarton and the G82 district, we handle rear extension steels from survey to sign-off. We also cover the surrounding towns and villages in West Dunbartonshire. The beam is sized by a structural engineer and inspected before it is boxed in.
We work alongside your builder or as the steel package within the wider build. We arrange the engineer's design, coordinate building standards, prop and open the rear wall at the right stage of the programme, and fit and pack the steels so the extension can be finished around them.
Worth knowing before you start
- 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.
- 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.
- The original rear wall of most houses is load-bearing because it supports first-floor joists and the bedroom wall above. Even where the joists run parallel to it, the masonry overhead still needs carrying, so steel is almost always part of opening it up.
- 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.
- 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.
Four stages, one team
Free visit
A short visit to Dumbarton 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 West Dunbartonshire 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.
Guide prices for rear extension steels in Dumbarton
As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Dumbarton, 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 column or post | £460–£1,360 per column | Column supplied and fitted with base and cap plates on a pad foundation |
| 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.
Approvals in Dumbarton
Steel beam work in Dumbarton needs a building warrant from West Dunbartonshire Council. The structural design is part of the application, and the council's building standards team accepts the completion certificate once the work is done as approved.
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.
Questions about rear extension steels in Dumbarton
How soon can rear extension steels start in Dumbarton?
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 party wall agreement for rear extension steels in Dumbarton?
There is no Party Wall Act in Scotland. Your title deeds and the general law apply instead, and the Tenements (Scotland) Act 2004 for flats, so agree the work with your neighbour in writing before it starts.
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.
Who designs the steels for a rear extension?
A structural engineer. Your architect's drawings show the layout, but the engineer calculates the beams, columns, connections and foundations. We arrange those calculations, or work from an engineer's design you already have, and make sure the details suit the builder's programme.
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.
Do you cover Dumbarton for rear extension steels?
Yes. We carry out rear extension steels in Dumbarton and the G82 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.