Steel BeamInstallers
Basement conversion with steel beams and a steel column on a concrete floor

Basement & cellar steels · Portsmouth

Basement & cellar steels in Portsmouth

Basement & cellar steels for homes in PO1, PO2, PO3, designed by a structural engineer.

  • Itemised written quote
  • Beam sized by a structural engineer
  • Covering Portsmouth and nearby

Free survey in Portsmouth

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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

Planning basement & cellar steels in Portsmouth

Basement & cellar steels in Portsmouth are planned around the house, not a standard kit. The wider Hampshire area is covered as well. We visit, measure and check what the wall carries, then arrange calculations and building control approval before any steel is ordered.

Underpinning and waterproofing are specialist trades, and we coordinate the steelwork with them rather than replacing them. Our part is the engineer's steel design, building control, temporary propping, and fitting the beams, columns and base plates at the right point in the dig, so the structure is sound before finishes go in.

Worth knowing before you start

  • Converting a cellar into a habitable room is building work needing building regulations approval, covering structure, fire escape, ventilation and damp protection. Digging out a new basement may also need planning permission, depending on the council and the scale of the work.
  • Underpinning deepens the existing foundations so walls can go lower, and a specialist carries it out in a strict bay-by-bay sequence. Steelwork has to fit around that sequence, which is why the engineer plans the two together from the start.
  • Basement projects run for weeks rather than days, and the steel goes in at set points during the dig. Noise, spoil removal and deliveries peak during excavation, and with careful planning the house above can often stay occupied.
  • Headroom is precious below ground, and a deep downstand beam can make a room feel cramped. The engineer may use a shallower but heavier section or set the steel into the ground floor zone, and that choice is made at design stage.
  • Temporary works for basements are more involved than for a single opening. The design covers propping the house above, supporting the sides of the excavation, and keeping loads off freshly cast concrete until it has gained strength.

How the job runs in Portsmouth

  1. 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.

  2. 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.

  3. 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.

  4. 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.

How much should I budget in Portsmouth?

As a guide, budget £2,800–£7,300 including VAT for basement or cellar steelwork in Portsmouth, based on published UK cost guides adjusted for prices in the South East (+12%).

JobTypical guide rangeWhat it usually covers
Basement or cellar steelwork£2,800–£7,300Beams and columns with pad foundations under the floor above (excavation and waterproofing extra)
Structural calculations for a beam£280–£840Site measure or photos, beam and padstone design and calculations for building control
Building control fees£280–£730Building notice or full plans fee and inspections; varies by council or approver
Temporary works and propping£170–£560Props, spreaders, needles and sole plates for a typical opening, installed and struck

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

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 Portsmouth City 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.

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.

Building rules in England

Basement & cellar steels near Portsmouth

Basement & cellar steels in Portsmouth: your questions

Who approves basement & cellar steels in Portsmouth?

Structural work in Portsmouth needs a building notice or full plans application to Portsmouth City Council 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.

Do you cover Portsmouth for basement & cellar steels?

Yes. We carry out basement & cellar steels in Portsmouth and the PO1, PO2, PO3, PO4 and PO5 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 paperwork will I get for basement steelwork?

You should end up with the engineer's calculations and drawings, the building control completion certificate, the waterproofing details and, where it applied, the party wall paperwork. Keep them together, as surveyors and solicitors usually ask for them when the property is sold or remortgaged.

Can I stay at home while basement steels are installed?

Many people do, particularly for cellar conversions where the dig is limited. Expect noise, dust and deliveries during the heavier stages, and some rooms above may be out of use while props are in place. For large excavations, moving out for part of the programme can be more comfortable.

Do you do the underpinning for a basement?

Underpinning is specialist work, and we coordinate the steelwork with the underpinning contractor rather than carrying it out ourselves. The engineer designs the steel and the underpinning sequence together, so beams, columns and new foundations fit the order in which the walls are deepened.

Do you also work near Portsmouth?

Yes. We also cover nearby towns including Gosport, Fareham, Havant and Waterlooville.

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.