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

Rear extension steels · Letchworth Garden City

Rear extension steels in Letchworth Garden City

Rear extension steels for homes in SG5, SG6, SG7, designed by a structural engineer.

  • Free survey visit in Letchworth Garden City
  • Engineer's calculations arranged
  • Building control handled for you

Free survey in Letchworth Garden City

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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

Planning rear extension steels in Letchworth Garden City

If you live in Letchworth Garden City, rear extension steels can usually be planned and priced after a single survey visit. It sits about 10.7 miles from Luton, which we also cover. We cover SG5, SG6 and SG7, and we fix the price in writing once the layout and scope are agreed.

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.

Things to plan for

  • 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.
  • 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.
  • 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.
  • 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.
  • 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.

From survey to sign-off in Letchworth Garden City

  1. Survey in Letchworth Garden City

    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 Letchworth Garden City?

As a guide, budget £2,650–£7,400 including VAT for opening into a rear extension in Letchworth Garden City, 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
Party wall surveyor (agreed surveyor, per neighbour)£950–£2,120 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 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 control and neighbours in Letchworth Garden City

For Letchworth Garden City, 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 Letchworth Garden City

Local questions answered

Do you cover Letchworth Garden City for rear extension steels?

Yes. We carry out rear extension steels in Letchworth Garden City and the SG5, SG6 and SG7 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

How much do rear extension steels cost in Letchworth Garden City?

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

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 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.

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.

What happens at the survey visit in Letchworth Garden City?

We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.

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.