Rear extension steels · Portsmouth
Rear extension steels in Portsmouth
Rear extension steels in Portsmouth, from free survey to completion certificate.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Portsmouth 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 Portsmouth
Portsmouth has a mix of housing, and rear extension steels need a slightly different approach in each. Our coverage runs across Hampshire, so nearby villages are included too. Whatever the age of the property, the steel goes in on proper bearings with temporary support in place throughout.
We work alongside your builder or as the steel package within the wider build. We arrange the engineer's design, coordinate building control, prop and open the rear wall at the right stage of the programme, and fit and pack the steels so the extension can be finished around them.
Things to plan for
- Two-storey rear extensions add a second level of loads to think about. Steels at first-floor level may carry the existing rear wall of the bedrooms or tie the new roof into the old one, so the engineer looks at both floors together.
- The opening is usually formed once the extension walls and roof are up, so the house stays secure and dry. Leaving it too late can hold up plastering and floor screeding, so the steel date is agreed with the builder early on.
- 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.
- 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 Portsmouth
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 Portsmouth 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 Portsmouth
As a guide, budget £2,800–£7,850 including VAT for opening into a rear extension in Portsmouth, 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 |
| Steel goalpost frame | £2,250–£6,700 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| Structural calculations for a beam | £280–£840 | Site measure or photos, beam and padstone design and calculations for building control |
| 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 Portsmouth
Structural openings in English homes need building regulations approval before work starts. Portsmouth City Council 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.
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 Portsmouth
- Gosport 1.7 mi
- Fareham 5.3 mi
- Havant 6.1 mi
- Waterlooville 6.2 mi
- Chichester 13.8 mi
- Hythe 14.2 mi
Rear extension steels in Portsmouth: your questions
Do I need a party wall agreement for rear extension steels in Portsmouth?
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.
Do you also work near Portsmouth?
Yes. We also cover nearby towns including Gosport, Fareham, Havant and Waterlooville.
When does the back wall come out during an extension build?
Usually once the extension walls and roof are up and the new space is weathertight. That keeps the house secure and dry while the opening is formed. The steel goes in, building control inspects it, and the builder then carries the floors and ceilings through.
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 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.
Can you work on older or listed homes in Portsmouth?
Yes. Older homes often have lime mortar, timber lintels or shallow footings, which the engineer allows for. Listed buildings need listed building consent for internal structural changes as well as building regulations approval, and that must be in place first.