Steel BeamInstallers
Rear extension under construction with a steel beam over the opening into the house

Rear extension steels · Bridgend

Rear extension steels in Bridgend

Calculations, approvals, propping, steel and making good for rear extension steels across Bridgend.

  • Free survey visit in Bridgend
  • Engineer's calculations arranged
  • Building control handled for you

Free survey in Bridgend

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  • 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 Bridgend: 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.

From the first survey visit to the completion certificate, we take care of rear extension steels across Bridgend. Coverage takes in Coity, Porthcawl and Maesteg and everywhere in between. The engineer sizes the steel, we deal with Bridgend County Borough Council, and our team fits and packs the beam before making good.

Things to plan for

  • 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 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.
  • 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.
  • 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.
  • A single beam works where solid masonry is left at both ends of the opening. Where the opening runs nearly the full width or the corners are weak, the engineer may use columns or a goalpost frame, which is two posts and a beam bolted together.

How the job runs in Bridgend

  1. Survey in Bridgend

    We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.

  2. Engineer's design

    A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.

  3. Building control

    We submit the application or notice to Bridgend County Borough Council under the Building Regulations as they apply in Wales, before work starts.

  4. Install and sign-off

    Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.

Guide prices for rear extension steels in Bridgend

As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Bridgend, based on published UK cost guides adjusted for prices in Wales (-9%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£2,300–£6,350Original 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£2,300–£6,350External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Party wall surveyor (agreed surveyor, per neighbour)£820–£1,820 per neighbourSchedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only)
Side return extension steelwork£3,200–£7,750Beams and posts along the old side wall line, propping and approvals (extension build extra)

Figures include our approximate regional adjustment for prices in Wales (-9%) and are rounded. How these figures are worked out.

Approvals in Bridgend

In Wales, structural alterations come under the Building Regulations 2010 as they apply in Wales. Bridgend County Borough Council handles building control for Bridgend. For work started or approved from 1 July 2026, the Welsh system uses an application to building control, dutyholders appointed in writing, a commencement notice before work starts and a compliance statement at the end.

Where the steel bears into a wall shared with next door, notice must be served under the Party Wall etc. Act 1996. If your neighbour dissents, surveyors agree how the work is done before it starts.

Building rules in Wales

Rear extension steels by town

Rear extension steels in Bridgend: your questions

Can you work on older or listed homes in Bridgend?

Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.

Which towns in Bridgend do you cover?

We cover towns including Coity, Maesteg and Porthcawl, plus the villages and smaller towns around them.

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.

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 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.

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.

How much do rear extension steels cost in Bridgend?

As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Bridgend, based on published UK cost guides adjusted for prices in Wales (-9%). 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.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.