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 Thatcham?
In Thatcham, a structural alteration typically costs £5,000–£10,500 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 South East, where labour and materials are typically about 12% above average. 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 |
The biggest cost drivers are:
- Moving radiators, sockets and pipes
- Flush or downstand beam
- Party wall involvement
- Floor and ceiling repairs
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 Thatcham?
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Making good, plastering and flooring repairs
- Structural engineer’s calculations and drawings
- Building control sign-off
- Temporary propping
- Party wall notices where needed
- Fire protection to the steel
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 Thatcham
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 Thatcham (RG18) 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
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 Thatcham
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
How much does a structural alteration cost in Thatcham?
In Thatcham, 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.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Do you build structural alterations in Thatcham?
Yes. We build structural alterations across Thatcham, including postcodes RG18. Every project starts with a free home visit.
