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Greater LondonStructural alterations and knock-throughs

Structural alterations and knock-throughs in Coulsdon

SK Developments builds structural alterations in Coulsdon, about 13 miles south of central London. We look after the design, the planning or permitted development check, building control and the build itself.

Guide price in Coulsdon

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

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

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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 Coulsdon?

In Coulsdon, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). That range is adjusted for London, where domestic building work typically costs around 30% above the national average. Design, structural calculations and council fees are extra.

Guide prices for Coulsdon, 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:

  • Party wall involvement
  • Span of the opening
  • Moving radiators, sockets and pipes
  • What sits above the wall

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 Coulsdon?

Whether you need planning permission depends on your house and its location 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.

Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.

We check this for your address before design work starts, so there are no surprises later.

What we handle

What we take care of:

  • Building control application
  • Building control sign-off
  • Making good, plastering and flooring repairs
  • Temporary propping
  • Fire protection to the steel
  • Party wall notices where needed

How long does it take?

Expect 1 to 2 weeks on site for a typical knock-through. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.

Building in Coulsdon

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 Coulsdon or close by in Purley, Wallington and Banstead, a free home visit is the first step.

How it works

  1. 01

    Survey and brief

    We visit, discuss your ideas and budget, and survey the property or site at no cost.

  2. 02

    Design and fixed quote

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

  3. 03

    Approvals in place

    We handle planning, building control and neighbour notices before work starts.

  4. 04

    Construction and completion

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

Questions about structural alterations in Coulsdon

How much does a structural alteration cost in Coulsdon?

In Coulsdon, 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.

Do I need building regulations approval?

Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.

Who approves a structural alteration in Coulsdon?

Planning matters in Coulsdon go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.

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 Coulsdon.

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

Call 0800 088 6248Get a guide price