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

Rear extension steels · Bexley

Rear extension steels in Bexley

Rear extension steels for homes in DA5, DA6, DA7, designed by a structural engineer.

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

Free survey in Bexley

Tell us about the rear extension steel job in Bexley.

Please enter your name.
Please enter a UK phone number.
Please enter a valid email.
Please enter a UK postcode.
Please tell us a little about the job.
  • Free survey visit
  • Engineer's calculations arranged
  • Building control handled
  • Fixed written price once scope is agreed
  • England, Wales, mainland Scotland & NI

About our rear extension steels service in Bexley

We carry out rear extension steels in Bexley, covering the DA5, DA6, DA7, DA8 and DA14 postcode districts. Our coverage runs across London, so nearby villages are included too. 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

  • 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.
  • 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 opening is usually formed once the extension walls and roof are up, so the house stays secure and dry. Leaving it too late can hold up plastering and floor screeding, so the steel date is agreed with the builder early on.
  • 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 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.

From survey to sign-off in Bexley

  1. Free visit

    A short visit to Bexley 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 Bexley?

As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Bexley, 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
Structural calculations for a beam£320–£960Site measure or photos, beam and padstone design and calculations for building control
Steel goalpost frame£2,550–£7,700Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
Rear wall opening for bi-fold or sliding doors£3,200–£8,950External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)

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

Building rules for Bexley

For Bexley, 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 Bexley

Questions about rear extension steels in Bexley

Do you also work near Bexley?

Yes. We also cover nearby towns including Welling, Dartford, Swanley and Eltham.

How soon can rear extension steels start in Bexley?

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.

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.

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 control 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.

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.