Rear extension steels · Richmond
Rear extension steels in Richmond
Rear extension steels for homes in SW14, TW1, TW2, designed by a structural engineer.
- Price fixed in writing once scope is agreed
- Building control arranged
- Temporary works and making good included
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Rear extension steels in Richmond: how it works
For homes in Richmond and the SW14, TW1, TW2, TW3 and TW7 districts, we handle rear extension steels from survey to sign-off. We also cover the surrounding towns and villages in London. The beam is sized by a structural engineer and inspected before it is boxed in.
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.
What to expect
- 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 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.
- 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.
- 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.
- 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.
From survey to sign-off in Richmond
Survey in Richmond
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.
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.
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.
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.
Guide prices for rear extension steels in Richmond
As a guide, budget £3,200–£8,950 including VAT for opening into a rear extension in Richmond, 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 |
| Side return extension steelwork | £4,500–£10,900 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| Structural calculations for a beam | £320–£960 | Site measure or photos, beam and padstone design and calculations for building control |
| Steel column or post | £640–£1,920 per column | Column supplied and fitted with base and cap plates on a pad foundation |
Figures include our approximate regional adjustment for London prices (+28%) and are rounded. How these figures are worked out.
Building rules for Richmond
In England, taking out a load-bearing wall or putting in a beam is building work under the Building Regulations 2010. It needs approval from building control, either the local council's building control team or a registered building control approver, through a full plans application or a building notice. Part A covers the structure and Part B covers fire safety, which is why steel in homes is usually fire protected.
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.
Questions about rear extension steels in Richmond
Can I stay at home while the work is done in Richmond?
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.
How soon can rear extension steels start in Richmond?
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 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.
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.
Can I use my own builder for the extension and you for the steels?
Yes. We can supply and fit the steel package while another builder handles the extension shell and finishes. Dates are agreed with them so the rear wall is opened at the right stage, and the engineer's details are shared so levels, padstones and foundations line up.
Do you also work near Richmond?
Yes. We also cover nearby towns including Isleworth, Hounslow, Barnes and Chiswick.