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 Uxbridge?
In Uxbridge, a structural alteration typically costs £5,750–£12,500 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Prices across London are typically 30% above the UK average for this kind of work, which is reflected in the range for Uxbridge. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £5,750–£12,500 |
| Higher specification | £12,500–£15,500 |
What moves the price most:
- Flush or downstand beam
- Span of the opening
- Party wall involvement
- What sits above the wall
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 Uxbridge?
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
Handled as part of most structural alterations:
- Steel beam supply and installation on padstones
- Making good, plastering and flooring repairs
- Fire protection to the steel
- Building control sign-off
- Structural engineer’s calculations and drawings
- Party wall notices where needed
How long does it take?
Allow 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 Uxbridge
Many London boroughs have conservation areas and detailed design guides, so early design advice saves time at the planning stage.
We work across Uxbridge and neighbouring areas such as Ruislip, Gerrards Cross and Northolt. Postcodes we cover in Uxbridge include UB8.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about structural alterations in Uxbridge
Do you build structural alterations in Uxbridge?
Yes. We build structural alterations across Uxbridge, including postcodes UB8. Every project starts with a free home visit.
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
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 Uxbridge?
In Uxbridge, a structural alteration typically costs £5,750–£12,500 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.
