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

Rear extension steels · Gosport

Rear extension steels in Gosport

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

  • Survey, design and installation in one
  • Covering PO12, PO13
  • Inspected before it is covered

Free survey in Gosport

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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 Gosport

Need rear extension steels in Gosport? Gosport is around 1.7 miles from Portsmouth, and we cover both. 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 PO12 and PO13 addresses.

Building a rear extension is only half of the open-plan result. The original back wall still holds up the first floor and the rear wall of the bedrooms above, so opening it needs steel. Depending on the width and what is left to bear on, that could be a single beam on padstones, a beam on columns, or a full goalpost frame.

Worth knowing before you start

  • 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.
  • 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.
  • 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.
  • 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.
  • Two-storey rear extensions add a second level of loads to think about. Steels at first-floor level may carry the existing rear wall of the bedrooms or tie the new roof into the old one, so the engineer looks at both floors together.

What happens, step by step

  1. Survey in Gosport

    We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.

  2. Engineer's design

    A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.

  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. Install and sign-off

    Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.

What do rear extension steels cost in Gosport?

As a guide, budget £2,800–£7,850 including VAT for opening into a rear extension in Gosport, based on published UK cost guides adjusted for prices in the South East (+12%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£2,800–£7,850Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Side return extension steelwork£3,900–£9,500Beams and posts along the old side wall line, propping and approvals (extension build extra)
Rear wall opening for bi-fold or sliding doors£2,800–£7,850External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)
Structural calculations for a beam£280–£840Site measure or photos, beam and padstone design and calculations for building control

Figures include our approximate regional adjustment for prices in the South East (+12%) and are rounded. How these figures are worked out.

Building rules for Gosport

For Gosport, 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.

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 Gosport

Questions about rear extension steels in Gosport

How soon can rear extension steels start in Gosport?

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.

Can you work on older or listed homes in Gosport?

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.

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.

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.

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.

Can I stay at home while the work is done in Gosport?

Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.

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.