What is a structural alteration?
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.
Structural work needs an engineer’s calculations and building control approval before work starts. In England and Wales, cutting into a party wall to support a beam also needs a party wall notice.
What we handle
- Structural engineer’s calculations and drawings
- Building control application
- Party wall notices where needed
- Temporary propping
- Steel beam supply and installation on padstones
- Fire protection to the steel
- Making good, plastering and flooring repairs
- Building control sign-off
Options to consider
Kitchen and dining knock-through
The most common open-plan change.
Chimney breast removal
Removing a breast needs support to the chimney above.
Opening to an extension
A wide opening between the house and a new extension.
Flush ceiling beam
The beam is hidden within the ceiling depth where possible.
How much does a structural alteration cost?
A structural alteration typically costs £4,500–£9,500 for a typical knock-through with steel beam across the UK, including VAT at 20% (standard rate). Build time is usually 1 to 2 weeks on site for a typical knock-through. Design, structural calculations and council fees are extra.
| Region | Guide range (for a typical knock-through with steel beam) |
|---|---|
| London | £5,750–£12,500 |
| South East | £5,000–£10,500 |
| East of England | £4,750–£10,000 |
| South West | £4,500–£9,750 |
| West Midlands | £4,250–£9,250 |
| East Midlands | £4,250–£9,000 |
| North West | £4,250–£9,000 |
| Yorkshire and the Humber | £4,250–£8,750 |
| North East | £4,000–£8,500 |
| Wales | £4,250–£8,750 |
| Scotland | £4,250–£9,250 |
| Northern Ireland | £3,750–£8,250 |
What changes the price:
- Span of the opening
- What sits above the wall
- Flush or downstand beam
- Party wall involvement
- Moving radiators, sockets and pipes
- Floor and ceiling repairs
Use the guide price tool for a figure based on your measurements, or see all guide prices.
Do I need planning permission?
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.
Wales
In Wales removing a load-bearing wall needs building regulations approval with structural calculations, and party wall notices where a shared wall is involved.
Scotland
In Scotland removing a load-bearing wall needs a building warrant before work starts.
Northern Ireland
In Northern Ireland removing a load-bearing wall needs building control approval from the council.
Even when planning permission is not needed, building regulations approval (a building warrant in Scotland) usually is. We make the applications and book the inspections.
How long does it take?
Typically 1 to 2 weeks on site for a typical knock-through. Surveys, design and approvals usually take 6 to 12 weeks beforehand.
How it works
- 01
Free visit
We look at the property, discuss what you want and measure up.
- 02
Design and fixed quote
Drawings, calculations and an itemised price for the agreed specification.
- 03
Approvals
Planning or permitted development, building regulations and neighbour matters.
- 04
Build and sign-off
Built to a written programme, with a completion certificate at the end.
Structural alterations and knock-throughs: questions and answers
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 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.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Do I need a party wall notice?
In England and Wales, if the beam sits in a party wall, yes.