Rear extension steels · Hounslow
Rear extension steels in Hounslow
Rear extension steels in Hounslow, from free survey to completion certificate.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Hounslow and nearby
- 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 Hounslow
We carry out rear extension steels in Hounslow, covering the TW1, TW2, TW3, TW4 and TW5 postcode districts. We also cover the surrounding towns and villages in London. The job starts with a free survey visit so the engineer's calculations are based on your actual walls, floors and loads.
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.
- 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.
- Opening the rear wall is usually the dustiest stage of an extension project. The work face is sheeted off from the rest of the house, and the kitchen is often out of use for a few days while the opening is formed and the steel goes in.
- 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.
From survey to sign-off in Hounslow
Free visit
A short visit to Hounslow to see the job, agree what you want and check the bearings, floors and services that affect the design.
Calculations
The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.
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.
Steel in, made good
On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.
How much should I budget in Hounslow?
As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Hounslow, based on published UK cost guides adjusted for London prices (+28%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £3,200–£8,950 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Steel column or post | £640–£1,920 per column | Column supplied and fitted with base and cap plates on a pad foundation |
| Rear wall opening for bi-fold or sliding doors | £3,200–£8,950 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Steel goalpost frame | £2,550–£7,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Building rules for Hounslow
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.
Questions about rear extension steels in Hounslow
How soon can rear extension steels start in Hounslow?
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.
Do you cover Hounslow for rear extension steels?
Yes. We carry out rear extension steels in Hounslow and the TW1, TW2, TW3, TW4 and TW5 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
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.
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.
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 stay at home while the work is done in Hounslow?
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.