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 Mid Glamorgan?
In Mid Glamorgan, 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 Mid Glamorgan 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 |
Your quote will depend mainly on:
- Flush or downstand beam
- Moving radiators, sockets and pipes
- Floor and ceiling repairs
- What sits above the wall
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 Mid Glamorgan?
Before anything is built in Mid Glamorgan, we confirm which approvals apply 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.
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:
- Fire protection to the steel
- Steel beam supply and installation on padstones
- Structural engineer’s calculations and drawings
- Building control application
- Making good, plastering and flooring repairs
- Temporary propping
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 Mid Glamorgan
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
Towns we cover in Mid Glamorgan include Bridgend, Merthyr Tydfil, Pontypridd, Aberdare, Caerphilly and Maesteg.
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 fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about structural alterations in Mid Glamorgan
Do I need planning permission for a structural alteration in Mid Glamorgan?
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 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.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Who approves a structural alteration in Mid Glamorgan?
Planning matters in Mid Glamorgan go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
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 Mid Glamorgan?
In Mid Glamorgan, 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.
