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 Antrim?
In Antrim, a structural alteration typically costs £3,750–£8,250 for a typical knock-through with steel beam, including VAT at 20% (standard rate). That range is adjusted for Northern Ireland, where domestic building work typically costs around 14% below the national average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical knock-through with steel beam | £3,750–£8,250 |
| Higher specification | £8,250–£10,500 |
What moves the price most:
- Span of the opening
- Moving radiators, sockets and pipes
- Flush or downstand beam
- Agreements with neighbours on shared walls
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 Antrim?
Whether you need planning permission depends on your house and its location in Northern Ireland. In Northern Ireland removing a load-bearing wall needs building control approval from the council.
In Northern Ireland building control approval comes from the council, usually through a full plans application or a building notice, with inspections during the work and a completion certificate at the end.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
What we take care of:
- Structural engineer’s calculations and drawings
- Written agreement with neighbours on shared walls
- Fire protection to the steel
- Steel beam supply and installation on padstones
- Building control sign-off
- Temporary propping
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 Antrim
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
We work across Antrim and neighbouring areas such as Ballymena, Newtownabbey and Belfast. Postcodes we cover in Antrim include BT41.
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
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about structural alterations in Antrim
Do I need building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.
Who approves a structural alteration in Antrim?
Planning matters in Antrim go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a structural alteration cost in Antrim?
In Antrim, a structural alteration typically costs £3,750–£8,250 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 Antrim?
In Northern Ireland removing a load-bearing wall needs building control approval from the council.
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.