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

Rear extension steels · Coulsdon

Rear extension steels in Coulsdon

Steelwork, approvals and making good for rear extension steels in Coulsdon and nearby.

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

Free survey in Coulsdon

Tell us about the rear extension steel job in Coulsdon.

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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

What rear extension steels involve in Coulsdon

We carry out rear extension steels in Coulsdon, covering the CR5, CR8 and SM6 postcode districts. The wider London area is covered as well. The job starts with a free survey visit so the engineer's calculations are based on your actual walls, floors and loads.

We work alongside your builder or as the steel package within the wider build. We arrange the engineer's design, coordinate building control, 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.

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.
  • Columns carry concentrated loads, so each normally sits on a pad foundation designed by the engineer. Digging these inside an existing kitchen or through a solid concrete floor takes planning, especially where drains run close to the back wall.
  • 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.
  • 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.
  • 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.

From survey to sign-off in Coulsdon

  1. Free visit

    A short visit to Coulsdon 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 a building notice or full plans application to the local council's building control team, so approval is in place before the wall is touched.

  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 Coulsdon?

As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Coulsdon, based on published UK cost guides adjusted for London prices (+28%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£3,200–£8,950Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Steel column or post£640–£1,920 per columnColumn supplied and fitted with base and cap plates on a pad foundation
Party wall surveyor (agreed surveyor, per neighbour)£1,150–£2,550 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£4,500–£10,900Beams and posts along the old side wall line, propping and approvals (extension build extra)

Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.

Approvals in Coulsdon

For Coulsdon, building control is provided by the local council's building control team, or by a registered building control approver if preferred. We send them the engineer's calculations with a building notice or full plans application and book the inspections. Work done without approval can cause problems at sale and is far dearer to put right later.

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.

Building rules in England

Rear extension steels near Coulsdon

Rear extension steels in Coulsdon: your questions

Do you also work near Coulsdon?

Yes. We also cover nearby towns including Purley, Banstead, Wallington and Sutton.

Who approves rear extension steels in Coulsdon?

Structural work in Coulsdon needs a building notice or full plans application to the local council's building control team or a registered building control approver. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.

Do I need a party wall agreement for extension steels?

In England and Wales, if a beam bears into a wall shared with a neighbour, or the extension foundations are dug close to theirs, notice under the Party Wall etc. Act 1996 is usually required. We can arrange the notices through a party wall surveyor. There is no equivalent legislation in Scotland or Northern Ireland.

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.

Do I need a steel beam for my rear extension?

If the original back wall is being opened up into the extension, almost certainly yes. That wall normally carries the first floor and the wall above, so a beam, columns or a goalpost frame takes over the job. A structural engineer confirms exactly what is needed once the opening width and loads are known.

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.