Rear extension steels · Derby
Rear extension steels in Derby
Rear extension steels for homes in DE1, DE3, DE21, designed by a structural engineer.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Derby and nearby
- 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 Derby: how it works
If you live in Derby, rear extension steels can usually be planned and priced after a single survey visit. The wider Derbyshire area is covered as well. We cover DE1, DE3, DE21, DE22 and DE23, 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.
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 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.
- 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.
- 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.
- Where the extension ceiling and the house ceiling should run through at one level, the steel may need setting higher into the floor zone or tying in with the extension roof structure. That choice changes the steel design, so it is settled before calculations.
What happens, step by step
Survey in Derby
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 Derby City Council, 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 Derby
As a guide, budget £2,450–£6,850 including VAT for opening into a rear extension in Derby, 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 |
| Rear wall opening for bi-fold or sliding doors | £2,450–£6,850 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Steel column or post | £490–£1,470 per column | Column supplied and fitted with base and cap plates on a pad foundation |
| 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.
Approvals in Derby
For Derby, building control is provided by Derby City Council, 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.
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 Derby
- Belper 6.9 mi
- Ilkeston 7.7 mi
- Heanor 8.1 mi
- Ripley 8.3 mi
- Long Eaton 8.7 mi
- Burton upon Trent 10.6 mi
Rear extension steels in Derby: your questions
Do you cover Derby for rear extension steels?
Yes. We carry out rear extension steels in Derby and the DE1, DE3, DE21, DE22 and DE23 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
What happens at the survey visit in Derby?
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.
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 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 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.