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EssexStructural alterations and knock-throughs

Structural alterations and knock-throughs in Brentwood

Thinking about a structural alteration in Brentwood? We can take it from first ideas to finished, signed-off work, with a written programme before work starts.

Guide price in Brentwood

£4,750–£10,000 for a typical knock-through with steel beam

In Brentwood, a structural alteration typically costs £4,750–£10,000 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 Brentwood?

In Brentwood, a structural alteration typically costs £4,750–£10,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). That range is adjusted for the East of England, where domestic building work typically costs around 6% above the national average. Design, structural calculations and council fees are extra.

Guide prices for Brentwood, including VAT at 20% (standard rate)
Size or typeGuide range
A typical knock-through with steel beam£4,750–£10,000
Higher specification£10,000–£12,500

Your quote will depend mainly on:

  • Party wall involvement
  • What sits above the wall
  • Floor and ceiling repairs
  • Flush or downstand beam

Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.

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

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.

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

On a typical structural alteration we handle:

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

How long does it take?

Allow 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 Brentwood

Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.

If your home is in Brentwood or close by in Billericay, Upminster and Hornchurch, 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 pricing

    Design options, then a fixed quote based on the chosen drawings and specification.

  3. 03

    Permissions sorted

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

  4. 04

    Construction and completion

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

Questions about structural alterations in Brentwood

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.

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 Brentwood?

In Brentwood, a structural alteration typically costs £4,750–£10,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.

Who approves a structural alteration in Brentwood?

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

Do I need a party wall notice?

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

Tell us about your project in Brentwood 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