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Greater LondonStructural alterations and knock-throughs

Structural alterations and knock-throughs in Islington

SK Developments designs, gets approval for and builds structural alterations in Islington and across Greater London, with one contract from the first drawing to the building control sign-off.

Guide price in Islington

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

In Islington, 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 Islington?

In Islington, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for London, where labour and materials are typically about 30% above average. Design, structural calculations and council fees are extra.

Guide prices for Islington, 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

The main things that change the cost:

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

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 Islington?

The approval route for Islington is set by planning law 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.

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

What we handle

From survey to sign-off, the job normally involves:

  • Party wall notices where needed
  • Building control sign-off
  • Making good, plastering and flooring repairs
  • Temporary propping
  • Steel beam supply and installation on padstones
  • Structural engineer’s calculations and drawings

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 Islington

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

Islington sits in Greater London, about 2 miles north-east of central London. We cover the whole of Islington, including postcodes EC1P, EC4P, EC50 and N1.

How it works

  1. 01

    Free visit

    We look at the property, talk through what you want and measure up. There is no charge and no obligation.

  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 Islington

Do I need a party wall notice?

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

How much does a structural alteration cost in Islington?

In Islington, 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 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 you build structural alterations in Islington?

Yes. We build structural alterations across Islington, including postcodes EC1P, EC4P, EC50 and N1. Every project starts with a free home visit.

Tell us about your project in Islington 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