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

Rear extension steels · Cambridge

Rear extension steels in Cambridge

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

  • Survey, design and installation in one
  • Covering CB2, CB4
  • Inspected before it is covered

Free survey in Cambridge

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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

About our rear extension steels service in Cambridge

Need rear extension steels in Cambridge? The wider Cambridgeshire area is covered as well. We survey the property, arrange the engineer's design, deal with local building control, fit the steel and make good, all under one quote for CB2 and CB4 addresses.

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.

Key points for your project

  • 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.
  • 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 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 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.

Four stages, one team

  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 Cambridge

As a guide, budget £2,650–£7,400 including VAT for opening into a rear extension in Cambridge, based on published UK cost guides adjusted for prices in the East of England (+6%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£2,650–£7,400Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Steel goalpost frame£2,100–£6,350Two posts and a beam bolted as a frame, pad foundations, base plates and fitting
Side return extension steelwork£3,700–£9,000Beams and posts along the old side wall line, propping and approvals (extension build extra)
Steel column or post£530–£1,590 per columnColumn supplied and fitted with base and cap plates on a pad foundation

Figures include our approximate regional adjustment for prices in the East of England (+6%) and are rounded. How these figures are worked out.

Building rules for Cambridge

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 Cambridge

Local questions answered

Do you cover Cambridge for rear extension steels?

Yes. We carry out rear extension steels in Cambridge and the CB2 and CB4 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

Who approves rear extension steels in Cambridge?

Structural work in Cambridge 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.

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.

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 soon can rear extension steels start in Cambridge?

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.