
Rear extension steels · Gerrards Cross
Rear extension steels in Gerrards Cross
Steelwork, approvals and making good for rear extension steels in Gerrards Cross and nearby.
- 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
What rear extension steels involve in Gerrards Cross
We carry out rear extension steels in Gerrards Cross, covering the SL9 and UB9 postcode districts. Gerrards Cross is around 5.6 miles from Slough, and we cover both. 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.
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.
- 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.
- 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.
- In older houses the rear wall may be solid brick in lime mortar, with timber lintels and shallow footings beneath. The engineer may ask for trial holes to see what the wall stands on before deciding where the steel will bear.
- In terraced and semi-detached houses one end of the beam often bears into the party wall. In England and Wales that is notifiable under the Party Wall etc. Act 1996, and the extension's own foundations near the boundary may need notices as well.
From survey to sign-off in Gerrards Cross
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.
Design and price
Calculations come back from the engineer and we confirm your fixed written price, line by line.
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.
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 Gerrards Cross
As a guide, budget £2,800–£7,850 including VAT for opening into a rear extension in Gerrards Cross, based on published UK cost guides adjusted for prices in the South East (+12%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,800–£7,850 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Party wall surveyor (agreed surveyor, per neighbour) | £1,000–£2,250 per neighbour | Schedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only) |
| Steel goalpost frame | £2,250–£6,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Steel column or post | £560–£1,680 per column | Column supplied and fitted with base and cap plates on a pad foundation |
Figures include our approximate regional adjustment for prices in the South East (+12%) and are rounded. How these figures are worked out.
Approvals in Gerrards Cross
For Gerrards Cross, 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.
Rear extension steels near Gerrards Cross
- Chalfont St Peter 1.6 mi
- Uxbridge 4.1 mi
- Rickmansworth 5.0 mi
- Slough 5.6 mi
- Ruislip 5.7 mi
- Amersham 6.2 mi
Rear extension steels in Gerrards Cross: your questions
Can I stay at home while the work is done in Gerrards Cross?
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 much do rear extension steels cost in Gerrards Cross?
As a guide, budget £2,800–£7,850 including VAT for opening into a rear extension in Gerrards Cross, based on published UK cost guides adjusted for prices in the South East (+12%). 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.
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.
What is a goalpost frame in an extension?
A goalpost frame is two steel columns with a beam across the top, bolted together and standing on their own foundations. It is used where the opening is so wide that little masonry is left to bear on, or where the existing corners cannot take the load. The engineer decides whether one is needed.
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.
Who approves rear extension steels in Gerrards Cross?
Structural work in Gerrards Cross needs a building notice or full plans application to the local council's building control team or a registered building control approver. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.