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

Basement & cellar steels · Sevenoaks

Basement & cellar steels in Sevenoaks

Basement & cellar steels for homes in TN13, TN14, designed by a structural engineer.

  • Survey, design and installation in one
  • Covering TN13, TN14
  • Inspected before it is covered

Free survey in Sevenoaks

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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

Basement & cellar steels in Sevenoaks: how it works

Need basement & cellar steels in Sevenoaks? We also work in nearby Maidstone, roughly 14.2 miles away. We survey the property, arrange the engineer's design, deal with local building control, fit the steel and make good, all under one quote for TN13 and TN14 addresses.

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.

What to expect

  • 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.
  • 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.
  • In terraced and semi-detached homes, basement work nearly always affects shared walls. Excavating near a neighbour's foundations and underpinning a party wall are both notifiable under the Party Wall etc. Act 1996 in England and Wales.
  • Below-ground rooms need a waterproofing design, often a cavity drain membrane, a tanking system or both. Column bases and beam bearings that pass through the waterproofing are detailed so they do not become a route for water.
  • 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.

What happens, step by step

  1. Survey in Sevenoaks

    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 the local council's building control team, 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 Sevenoaks?

As a guide, budget £2,800–£7,300 including VAT for basement or cellar steelwork in Sevenoaks, 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)
Fire protection to a steel beam£170–£670 per beamFire-rated board boxing or an intumescent coating system as specified
Party wall surveyor (agreed surveyor, per neighbour)£1,000–£2,250 per neighbourSchedule of condition and award where a neighbour dissents; serving notice alone, where the neighbour consents, costs far less (England and Wales only)
Steel column or post£560–£1,680 per columnColumn 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.

Building rules for Sevenoaks

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.

Building rules in England

Basement & cellar steels near Sevenoaks

Basement & cellar steels in Sevenoaks: your questions

Do you cover Sevenoaks for basement & cellar steels?

Yes. We carry out basement & cellar steels in Sevenoaks and the TN13 and TN14 postcode districts. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.

Do I need planning permission to convert a cellar?

Converting an existing cellar into living space usually does not need planning permission if the outside of the house is unchanged, though listed buildings need consent. Digging a new basement, extending under the garden or adding lightwells may need planning permission, and building regulations approval is needed either way.

Do I need a party wall notice for basement work?

In England and Wales usually yes, if you are excavating near a neighbour's foundations within the distances the Party Wall etc. Act 1996 sets, or underpinning a shared wall. Notice periods apply before that work starts. We arrange a party wall surveyor to handle the notices, though we do not give legal advice.

Will columns be needed in my basement?

Quite often. Below ground there may be no suitable wall to support the end of a beam, so a column carries the load down to a foundation. The position can usually be agreed with you at design stage so the column sits within a wall line, a kitchen island or a storage area.

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.