Steel BeamInstallers
Rear extension under construction with a steel beam over the opening into the house

Rear extension steels · Portishead

Rear extension steels in Portishead

Rear extension steels in Portishead, from free survey to completion certificate.

  • Price fixed in writing once scope is agreed
  • Building control arranged
  • Temporary works and making good included

Free survey in Portishead

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  • 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 Portishead

Rear extension steels in Portishead are planned around the house, not a standard kit. We also cover the surrounding towns and villages in Somerset. We visit, measure and check what the wall carries, then arrange calculations and building control approval before any steel is ordered.

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 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.
  • During the opening, props stand both inside the house and within the extension footprint. Where props bear on a newly laid slab, the propping plan checks that the slab can take those point loads, using spreaders where needed.
  • Opening the rear wall is usually the dustiest stage of an extension project. The work face is sheeted off from the rest of the house, and the kitchen is often out of use for a few days while the opening is formed and the steel goes in.
  • 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 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.

From survey to sign-off in Portishead

  1. 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.

  2. Design and price

    Calculations come back from the engineer and we confirm your fixed written price, line by line.

  3. Building control

    We submit a building notice or full plans application to North Somerset Council, so approval is in place before the wall is touched.

  4. Fit, inspect, finish

    The work is propped and the steel installed and packed tight. After inspection the opening is boxed, plastered and left clean.

How much should I budget in Portishead?

As a guide, budget £2,600–£7,200 including VAT for opening into a rear extension in Portishead, based on published UK cost guides adjusted for prices in the South West (+3%).

JobTypical guide rangeWhat it usually covers
Opening into a rear extension£2,600–£7,200Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build
Structural calculations for a beam£260–£770Site measure or photos, beam and padstone design and calculations for building control
Party wall surveyor (agreed surveyor, per neighbour)£930–£2,060 per neighbourSchedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only)
Rear wall opening for bi-fold or sliding doors£2,600–£7,200External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately)

Figures include our approximate regional adjustment for prices in the South West (+3%) and are rounded. How these figures are worked out.

Approvals in Portishead

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 North Somerset Council 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.

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.

Building rules in England

Rear extension steels near Portishead

Local questions answered

What happens at the survey visit in Portishead?

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.

How much do rear extension steels cost in Portishead?

As a guide, budget £2,600–£7,200 including VAT for opening into a rear extension in Portishead, based on published UK cost guides adjusted for prices in the South West (+3%). 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.

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.

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.

Do you also work near Portishead?

Yes. We also cover nearby towns including Nailsea, Clevedon, Kingswood and Mangotsfield.

Planning to take a wall out?

Book a free survey visit. You get an itemised written quote covering calculations, building control, steel and making good.