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

Rear extension steels · Llandeilo

Rear extension steels in Llandeilo

Rear extension steels in Llandeilo, from free survey to completion certificate.

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Llandeilo

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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

Planning rear extension steels in Llandeilo

Need rear extension steels in Llandeilo? The wider Carmarthenshire area is covered as well. We survey the property, arrange the engineer's design, deal with Carmarthenshire County Council, fit the steel and make good, all under one quote for SA19 addresses.

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.

Key points for your project

  • 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.
  • 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.
  • 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 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.
  • 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.

Four stages, one team

  1. Free visit

    A short visit to Llandeilo to see the job, agree what you want and check the bearings, floors and services that affect the design.

  2. Calculations

    The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.

  3. Building control

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

  4. 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.

How much should I budget in Llandeilo?

As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Llandeilo, 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
Steel goalpost frame£1,800–£5,450Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
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)
Structural calculations for a beam£230–£680Site measure or photos, beam and padstone design and calculations for building control

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

Approvals in Llandeilo

Welsh building regulations treat beams and new openings as controlled building work. We apply to Carmarthenshire County Council on your behalf before anything is removed, give the commencement notice the 2026 Welsh rules require, and the steel is checked before it is boxed in.

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 near Llandeilo

Rear extension steels in Llandeilo: your questions

Do you cover Llandeilo for rear extension steels?

Yes. We carry out rear extension steels in Llandeilo and the SA19 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

How much do rear extension steels cost in Llandeilo?

As a guide, budget £2,300–£6,350 including VAT for opening into a rear extension in Llandeilo, 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.

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.

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.

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.

How soon can rear extension steels start in Llandeilo?

Start dates depend on the engineer's calculations, the building control approval and, where needed, party wall notice periods. We give you a realistic timetable after the survey and keep you updated as each approval comes through.

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.