SK Developments Free home visit0800 088 6248 Get a quote

Greater LondonStructural alterations and knock-throughs

Structural alterations and knock-throughs in Chelsea

We take on structural alterations in Chelsea, about 2 miles south-west of central London, handling the drawings, approvals and construction so you deal with one company throughout.

Guide price in Chelsea

£5,750–£12,500 for a typical knock-through with steel beam

In Chelsea, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate).

Book a free home visit

Tell us about your project. We reply to arrange a visit and a fixed quote.

Free home visit and measured survey
Fixed price for the agreed specification
Drawings, approvals and build in one contract
Building control sign-off arranged
England, Wales, Scotland and Northern Ireland

What is a structural alteration?

Steel beam installed across a wide opening with props in place during a knock-through

A structural alteration changes how a house carries its loads, most often by removing a load-bearing wall and replacing it with a steel beam. It is how kitchens and dining rooms become open-plan, and how extensions are joined to the original house.

How much does a structural alteration cost in Chelsea?

In Chelsea, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). The guide for Chelsea reflects typical costs in London, roughly 30% above the UK-wide figure. Design, structural calculations and council fees are extra.

Guide prices for Chelsea, including VAT at 20% (standard rate)
Size or typeGuide range
A typical knock-through with steel beam£5,750–£12,500
Higher specification£12,500–£15,500

What moves the price most:

  • Span of the opening
  • Party wall involvement
  • Floor and ceiling repairs
  • Flush or downstand beam

Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.

Do you need planning permission for a structural alteration in Chelsea?

Here is how the rules work for a structural alteration in England. In England removing a load-bearing wall does not need planning permission but does need building regulations approval with an engineer’s calculations. If the beam bears on a party wall, a party wall notice must be served.

Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.

At the survey we check your house’s planning history and any restrictions, and tell you which route applies.

What we handle

What we take care of:

  • Building control sign-off
  • Temporary propping
  • Building control application
  • Party wall notices where needed
  • Fire protection to the steel
  • Steel beam supply and installation on padstones

How long does it take?

The build itself usually takes 1 to 2 weeks on site for a typical knock-through. Before that, surveys, drawings and approvals usually take 6 to 12 weeks, longer if the council asks for changes.

Building in Chelsea

Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.

If your home is in Chelsea or close by in Battersea, Wandsworth and Kensington, a free home visit is the first step.

How it works

  1. 01

    Visit and measured survey

    A free visit to understand the project, check access and take measurements.

  2. 02

    Design and fixed quote

    Drawings, structural calculations and an itemised, fixed price for the agreed specification.

  3. 03

    Approvals

    Planning or permitted development confirmation, building regulations and any party wall matters.

  4. 04

    Construction and completion

    We build, put right any snags and hand over the building control certificate.

Questions about structural alterations in Chelsea

What fire protection does a steel need?

Usually fire-rated plasterboard or intumescent paint, as building control requires.

How much does a structural alteration cost in Chelsea?

In Chelsea, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.

Can the beam be hidden?

Often, by setting it within the ceiling depth. It depends on the joists and span.

How long does a structural alteration take in Chelsea?

Typically 1 to 2 weeks on site for a typical knock-through. Design and approvals beforehand usually take 6 to 12 weeks.

How do I know if a wall is load-bearing?

Only a survey can confirm it. Walls that carry floor joists, roof loads or walls above are load-bearing. We check on site and the engineer confirms.

Start with a guide price, then book a free survey for a fixed quote in Chelsea.

Call 0800 088 6248 or get an instant guide price online.

Call 0800 088 6248Get a guide price