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 Bangor, Gwynedd?
In Bangor, 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 Bangor 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
- What sits above the wall
- Party wall involvement
- Floor and ceiling repairs
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 Bangor, Gwynedd?
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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
From survey to sign-off, the job normally involves:
- Structural engineer’s calculations and drawings
- Temporary propping
- Making good, plastering and flooring repairs
- Steel beam supply and installation on padstones
- Building control application
- Building control sign-off
How long does it take?
Allow 1 to 2 weeks on site for a typical knock-through. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Bangor, Gwynedd
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
We work across Bangor and neighbouring areas such as Caernarfon, Llandudno and Colwyn Bay. Postcodes we cover in Bangor include LL57.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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 Bangor, Gwynedd
How much does a structural alteration cost in Bangor?
In Bangor, 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.
Do I need planning permission for a structural alteration in Bangor?
In Wales removing a load-bearing wall needs building regulations approval with structural calculations, and party wall notices where a shared wall is involved.
Who approves a structural alteration in Bangor?
Planning matters in Bangor go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
Do I need building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.