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.
How much does a structural alteration cost in Leigh?
In Leigh, a structural alteration typically costs £4,250–£9,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Building costs in the North West run about 6% below the UK average, and the figures for Leigh are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £4,250–£9,000 |
| Higher specification | £9,000–£11,000 |
Your quote will depend mainly on:
- Flush or downstand beam
- Span of the opening
- What sits above the wall
- Moving radiators, sockets and pipes
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 Leigh?
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.
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
From survey to sign-off, the job normally involves:
- Making good, plastering and flooring repairs
- Fire protection to the steel
- Building control sign-off
- Steel beam supply and installation on padstones
- Building control application
- Temporary propping
How long does it take?
Expect 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 Leigh
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
We work across Leigh and neighbouring areas such as Atherton, Tyldesley and Golborne. Postcodes we cover in Leigh include WN7.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about structural alterations in Leigh
How much does a structural alteration cost in Leigh?
In Leigh, a structural alteration typically costs £4,250–£9,000 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 you build structural alterations in Leigh?
Yes. We build structural alterations across Leigh, including postcodes WN7. Every project starts with a free home visit.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
Do I need building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.
