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

Rear extension steels · Derbyshire

Rear extension steels in Derbyshire

Survey, engineer's design and installation of rear extension steels anywhere in Derbyshire.

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

Free survey in Derbyshire

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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 Derbyshire

Rear extension steels are the beams, columns and frames that let the original back wall of a house be opened up into a new extension. Sized by a structural engineer, they pick up the floor, wall and roof loads that the old wall carried and pass them into bearings or foundations, so the new and old spaces join as one open room.

We carry out rear extension steels throughout Derbyshire, for homeowners, landlords and builders who need the structural part done properly. Coverage takes in Long Eaton, Staveley and Ripley and everywhere in between. You get an itemised written quote that shows the calculations, approvals, steel, labour and finishing as separate lines.

Things to plan for

  • 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.
  • 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.
  • 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.

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 Derbyshire

As a guide, budget £2,450–£6,850 including VAT for opening into a rear extension in Derbyshire, based on published UK cost guides adjusted for prices in the East Midlands (-2%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£2,450–£6,850Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Structural calculations for a beam£240–£740Site measure or photos, beam and padstone design and calculations for building control
Party wall surveyor (agreed surveyor, per neighbour)£880–£1,960 per neighbourSchedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only)
Rear wall opening for bi-fold or sliding doors£2,450–£6,850External 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 prices in the East Midlands (-2%) and are rounded. How these figures are worked out.

Building control and neighbours in Derbyshire

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.

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 in Derbyshire: your questions

Which towns in Derbyshire do you cover?

We cover towns including Derby, Chesterfield, Long Eaton and Ilkeston, plus the villages and smaller towns around them.

How much do rear extension steels cost in Derbyshire?

As a guide, budget £2,450–£6,850 including VAT for opening into a rear extension in Derbyshire, based on published UK cost guides adjusted for prices in the East Midlands (-2%). 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.

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.

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.

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.

Do I need a party wall agreement for rear extension steels in Derbyshire?

Yes, if the beam bears into a shared wall: the Party Wall etc. Act 1996 applies in England and Wales, and a party structure notice must be served at least two months before that work starts. We arrange it through a party wall surveyor.

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.