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Greater LondonStructural alterations and knock-throughs

Structural alterations and knock-throughs in Hayes

Our structural alteration service covers Hayes and the surrounding parts of Greater London. Every project starts with a free visit and ends with a completion certificate.

Guide price in Hayes

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

In Hayes, 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 Hayes?

In Hayes, 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 Hayes, 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

Your quote will depend mainly on:

  • Party wall involvement
  • Floor and ceiling repairs
  • Moving radiators, sockets and pipes
  • What sits above the wall

A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.

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

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.

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.

Our first visit includes a check of your planning history, so you know the route before paying for drawings.

What we handle

On a typical structural alteration we handle:

  • Building control application
  • Steel beam supply and installation on padstones
  • Building control sign-off
  • Party wall notices where needed
  • Structural engineer’s calculations and drawings
  • Fire protection to the steel

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 Hayes

Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.

We work across Hayes and neighbouring areas such as Richmond, Chiswick and Barnes. Postcodes we cover in Hayes include TW8 and TW9.

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

    Permissions sorted

    Applications, building control and neighbour arrangements, all before the start date.

  4. 04

    Build and sign-off

    We run the build to a written programme and hand over the completion certificate.

Questions about structural alterations in Hayes

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 Hayes?

In Hayes, 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.

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.

Do I need a party wall notice?

In England and Wales, if the beam sits in a party wall, yes.

Who approves a structural alteration in Hayes?

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

Tell us about your project in Hayes and we will arrange a free home visit.

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

Call 0800 088 6248Get a guide price