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

Rear extension steels · Croydon

Rear extension steels in Croydon

Rear extension steels for homes in CR0, CR2, CR7, designed by a structural engineer.

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

Free survey in Croydon

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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 Croydon

Planning rear extension steels in Croydon? Our team covers CR0, CR2, CR7, CR9 and SE19 and the streets around them. The wider London area is covered as well. You get one written quote for the calculations, approvals, propping, steel and making good.

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.

What to expect

  • 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.
  • In terraced and semi-detached houses one end of the beam often bears into the party wall. In England and Wales that is notifiable under the Party Wall etc. Act 1996, and the extension's own foundations near the boundary may need notices as well.
  • 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.
  • 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.
  • 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.

What happens, step by step

  1. Look and measure

    We check the wall, the span you want and what the wall is carrying, and photograph anything the engineer needs to see.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  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. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

Guide prices for rear extension steels in Croydon

As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Croydon, 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
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)
Steel goalpost frame£2,550–£7,700Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
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.

Building control and neighbours in Croydon

Structural openings in English homes need building regulations approval before work starts. The local council's building control team can deal with it, or you can use a registered building control approver. Either way the steel is inspected before it is covered, and a completion certificate is issued at the end. Keep it safe for when you sell.

Terraced and semi-detached homes often need party wall notices, because cutting into a shared wall to take a beam end is notifiable under the Party Wall etc. Act 1996. Allow at least two months for the notice period unless your neighbour agrees sooner.

Building rules in England

Rear extension steels near Croydon

Local questions answered

How much do rear extension steels cost in Croydon?

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

How soon can rear extension steels start in Croydon?

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.

When does the back wall come out during an extension build?

Usually once the extension walls and roof are up and the new space is weathertight. That keeps the house secure and dry while the opening is formed. The steel goes in, building control inspects it, and the builder then carries the floors and ceilings through.

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 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.

Can you work on older or listed homes in Croydon?

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.

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.