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 County Antrim?
In County Antrim, a structural alteration typically costs £3,750–£8,250 for a typical knock-through with steel beam, including VAT at 20% (standard rate). Building costs in Northern Ireland run about 14% below the UK average, and the figures for County Antrim are adjusted to reflect that. 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:
- Floor and ceiling repairs
- Agreements with neighbours on shared walls
- Flush or downstand beam
- 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 County Antrim?
Approvals for a structural alteration in County Antrim follow the rules for 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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical structural alteration we handle:
- Building control application
- Building control sign-off
- Temporary propping
- Fire protection to the steel
- Structural engineer’s calculations and drawings
- Written agreement with neighbours on shared walls
How long does it take?
Build time is typically 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 County Antrim
Across Northern Ireland, bungalows and chalet bungalows are common, so loft conversions and rear extensions are popular projects.
Towns we cover in County Antrim include Belfast, Lisburn, Newtownabbey, Carrickfergus, Ballymena and Antrim.
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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about structural alterations in County Antrim
Do I need planning permission for a structural alteration in County Antrim?
In Northern Ireland removing a load-bearing wall needs building control approval from the council.
How long does a structural alteration take in County Antrim?
Typically 1 to 2 weeks on site for a typical knock-through. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a structural alteration cost in County Antrim?
In County 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.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
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.