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 Lancashire?
In Lancashire, a structural alteration typically costs £4,250–£9,000 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 the North West, where labour and materials are typically about 6% below average. 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 |
The biggest cost drivers are:
- Moving radiators, sockets and pipes
- Flush or downstand beam
- Floor and ceiling repairs
- Span of the opening
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 Lancashire?
Before anything is built in Lancashire, we confirm which approvals apply 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical structural alteration we handle:
- Structural engineer’s calculations and drawings
- Temporary propping
- Building control sign-off
- Steel beam supply and installation on padstones
- Fire protection to the steel
- Making good, plastering and flooring repairs
How long does it take?
Build time is typically 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 Lancashire
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Towns we cover in Lancashire include Preston, Burnley, Blackburn, Blackpool, Fylde and Rossendale.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed 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 Lancashire
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 Lancashire?
In Lancashire, 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 long does a structural alteration take in Lancashire?
Typically 1 to 2 weeks on site for a typical knock-through. Design and approvals beforehand usually take 6 to 12 weeks.
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.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.