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 Walton-on-Thames?
In Walton-on-Thames, a structural alteration typically costs £5,000–£10,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Prices across the South East are typically 12% above the UK average for this kind of work, which is reflected in the range for Walton-on-Thames. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £5,000–£10,500 |
| Higher specification | £10,500–£13,000 |
Your quote will depend mainly on:
- What sits above the wall
- Moving radiators, sockets and pipes
- Party wall involvement
- Flush or downstand beam
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 Walton-on-Thames?
Before anything is built in Walton-on-Thames, 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
The work we manage on a structural alteration:
- Building control application
- Making good, plastering and flooring repairs
- Fire protection to the steel
- Party wall notices where needed
- Temporary propping
- Building control sign-off
How long does it take?
Build time is typically 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 Walton-on-Thames
The South East has a broad mix of housing, from Victorian terraces in the towns to post-war semis and newer estates, so extension types vary street by street.
Projects in Walton-on-Thames (KT12) are surveyed in person before we quote, so the price reflects your actual property.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about structural alterations in Walton-on-Thames
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.
How much does a structural alteration cost in Walton-on-Thames?
In Walton-on-Thames, a structural alteration typically costs £5,000–£10,500 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 Walton-on-Thames?
Planning matters in Walton-on-Thames 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 a party wall notice?
In England and Wales, if the beam sits in a party wall, yes.
