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East SussexStructural alterations and knock-throughs

Structural alterations and knock-throughs in Seaford

SK Developments builds structural alterations in Seaford, about 11 miles east of Brighton. We look after the design, the planning or permitted development check, building control and the build itself.

Guide price in Seaford

£5,000–£10,500 for a typical knock-through with steel beam

In Seaford, a structural alteration typically costs £5,000–£10,500 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 Seaford?

In Seaford, a structural alteration typically costs £5,000–£10,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). That range is adjusted for the South East, where domestic building work typically costs around 12% above the national average. Design, structural calculations and council fees are extra.

Guide prices for Seaford, including VAT at 20% (standard rate)
Size or typeGuide range
A typical knock-through with steel beam£5,000–£10,500
Higher specification£10,500–£13,000

The biggest cost drivers are:

  • What sits above the wall
  • Flush or downstand beam
  • Moving radiators, sockets and pipes
  • Party wall involvement

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 Seaford?

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.

If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.

What we handle

What we take care of:

  • Building control application
  • Steel beam supply and installation on padstones
  • Structural engineer’s calculations and drawings
  • Party wall notices where needed
  • Building control sign-off
  • Temporary propping

How long does it take?

Allow 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 Seaford

Commuter towns across the South East have many 1930s and post-war semis that suit rear extensions and hip-to-gable loft conversions.

Seaford sits in East Sussex, about 11 miles east of Brighton. We cover the whole of Seaford, including postcodes BN25.

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 pricing

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

  3. 03

    Approvals

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

  4. 04

    Build and handover

    Work follows the agreed programme, with inspections along the way and a completion certificate at the end.

Questions about structural alterations in Seaford

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.

How much does a structural alteration cost in Seaford?

In Seaford, a structural alteration typically costs £5,000–£10,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.

Do I need building regulations approval?

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

How long does a knock-through take?

Usually 1 to 2 weeks on site, plus a few days for plastering to dry.

Who approves a structural alteration in Seaford?

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

Get a free, no-obligation home visit for your structural alteration in Seaford.

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

Call 0800 088 6248Get a guide price