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 Chepstow?
In Chepstow, a structural alteration typically costs £4,250–£8,750 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 Wales, where labour and materials are typically about 8% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £4,250–£8,750 |
| Higher specification | £8,750–£11,000 |
The main things that change the cost:
- What sits above the wall
- Moving radiators, sockets and pipes
- Span of the opening
- 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 Chepstow?
Whether you need planning permission depends on your house and its location in Wales. In Wales removing a load-bearing wall needs building regulations approval with structural calculations, and party wall notices where a shared wall is involved.
Building regulations in Wales are set by the Welsh Government. Approval comes from the council’s building control service or a registered building control approver, with inspections during the work and a completion certificate at the end.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
Handled as part of most structural alterations:
- Building control sign-off
- Making good, plastering and flooring repairs
- Steel beam supply and installation on padstones
- Party wall notices where needed
- Temporary propping
- Fire protection to the steel
How long does it take?
Expect 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 Chepstow
Wales has many terraced valley streets, stone cottages and post-war estates, so extension designs are shaped by slopes, materials and local character.
We work across Chepstow and neighbouring areas such as Caldicot, Monmouth and Newport. Postcodes we cover in Chepstow include NP16.
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 pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about structural alterations in Chepstow
Do you build structural alterations in Chepstow?
Yes. We build structural alterations across Chepstow, including postcodes NP16. Every project starts with a free home visit.
Do I need planning permission for a structural alteration in Chepstow?
In Wales removing a load-bearing wall needs building regulations approval with structural calculations, and party wall notices where a shared wall is involved.
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 Chepstow?
In Chepstow, a structural alteration typically costs £4,250–£8,750 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.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
