Rear extension steels · Northampton
Rear extension steels in Northampton
Steelwork, approvals and making good for rear extension steels in Northampton and nearby.
- Free survey visit in Northampton
- Engineer's calculations arranged
- Building control handled for you
- 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 Northampton
We carry out rear extension steels in Northampton, covering the NN1, NN2, NN3, NN4 and NN5 postcode districts. We also cover the surrounding towns and villages in Northamptonshire. 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.
Key points for your project
- The steelwork forms part of the extension's building regulations approval, and the engineer's calculations go in with it. Planning for the extension itself is separate; many rear extensions to houses in England fall within permitted development, subject to size limits and conditions.
- 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.
- 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.
- 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.
- 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.
What happens, step by step
Survey in Northampton
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.
What do rear extension steels cost in Northampton?
As a guide, budget £2,450–£6,850 including VAT for opening into a rear extension in Northampton, based on published UK cost guides adjusted for prices in the East Midlands (-2%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Opening into a rear extension | £2,450–£6,850 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| Side return extension steelwork | £3,450–£8,350 | Beams and posts along the old side wall line, propping and approvals (extension build extra) |
| Structural calculations for a beam | £240–£740 | Site measure or photos, beam and padstone design and calculations for building control |
| Steel goalpost frame | £1,950–£5,900 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
Figures include our approximate regional adjustment for prices in the East Midlands (-2%) and are rounded. How these figures are worked out.
Building control and neighbours in Northampton
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.
Rear extension steels near Northampton
- Wellingborough 8.8 mi
- Daventry 11.7 mi
- Rushden 12.2 mi
- Kettering 12.2 mi
- Milton Keynes 15.4 mi
- Market Harborough 15.8 mi
Rear extension steels in Northampton: your questions
Can I stay at home while the work is done in Northampton?
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.
Do I need a party wall agreement for rear extension steels in Northampton?
Yes, if the beam bears into a shared wall: the Party Wall etc. Act 1996 applies in England and Wales, and a party structure notice must be served at least two months before that work starts. We arrange it through a party wall surveyor.
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.
Will my kitchen be out of action while the rear wall is opened?
For a few days, usually. The kitchen often sits against the rear wall, so units, sinks or appliances near the opening may need disconnecting while the wall is propped and removed. The work area is sheeted off and the rest of the house stays in use.
Is the steel included in the extension's building regulations?
Yes. The steelwork is part of the extension, so the engineer's calculations go to building control with the extension application and the steel is inspected before it is covered. The completion certificate issued for the extension then covers the structural work to the rear wall.