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 Monmouth?
In Monmouth, a structural alteration typically costs £4,250–£8,750 for a typical knock-through with steel beam, including VAT at 20% (standard rate). The guide for Monmouth reflects typical costs in Wales, roughly 8% below the UK-wide figure. 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
- Floor and ceiling repairs
- Moving radiators, sockets and pipes
- Party wall involvement
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a structural alteration in Monmouth?
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.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
The work we manage on a structural alteration:
- Building control sign-off
- Making good, plastering and flooring repairs
- Building control application
- Party wall notices where needed
- Steel beam supply and installation on padstones
- 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. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Monmouth
Wales has many terraced valley streets, stone cottages and post-war estates, so extension designs are shaped by slopes, materials and local character.
If your home is in Monmouth or close by in Chepstow, Abergavenny and Caldicot, a free home visit is the first step.
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 in place
We handle planning, building control and neighbour notices before work starts.
- 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 Monmouth
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Do you build structural alterations in Monmouth?
Yes. We build structural alterations across Monmouth, including postcodes NP25. Every project starts with a free home visit.
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 planning permission for a structural alteration in Monmouth?
In Wales removing a load-bearing wall needs building regulations approval with structural calculations, and party wall notices where a shared wall is involved.
How much does a structural alteration cost in Monmouth?
In Monmouth, 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 long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.