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 Horwich?
In Horwich, a structural alteration typically costs £4,250–£9,000 for a typical knock-through with steel beam, including VAT at 20% (standard rate). The guide for Horwich reflects typical costs in the North West, roughly 6% below the UK-wide figure. 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:
- Floor and ceiling repairs
- Span of the opening
- What sits above the wall
- Party wall involvement
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a structural alteration in Horwich?
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.
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
The work we manage on a structural alteration:
- Fire protection to the steel
- Building control application
- Steel beam supply and installation on padstones
- Building control sign-off
- Temporary propping
- Party wall notices where needed
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 Horwich
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
If your home is in Horwich or close by in Westhoughton, Chorley and Hindley, a free home visit is the first step.
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
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 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 Horwich
How much does a structural alteration cost in Horwich?
In Horwich, 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.
Who approves a structural alteration in Horwich?
Planning matters in Horwich 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 building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
