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 Wilmslow?
In Wilmslow, 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:
- Flush or downstand beam
- What sits above the wall
- Span of the opening
- Moving radiators, sockets and pipes
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a structural alteration in Wilmslow?
Before anything is built in Wilmslow, 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.
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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
Handled as part of most structural alterations:
- Making good, plastering and flooring repairs
- Building control sign-off
- Structural engineer’s calculations and drawings
- Temporary propping
- Steel beam supply and installation on padstones
- 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 Wilmslow
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
Our Wilmslow coverage includes postcode districts SK9, and we also work in nearby places such as Cheadle Hulme, Hazel Grove and Altrincham.
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
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about structural alterations in Wilmslow
Do I need building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.
Do I need a party wall notice?
In England and Wales, if the beam sits in a party wall, yes.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
How much does a structural alteration cost in Wilmslow?
In Wilmslow, 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.
Do you build structural alterations in Wilmslow?
Yes. We build structural alterations across Wilmslow, including postcodes SK9. Every project starts with a free home visit.
