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 Belfast?
In Belfast, a structural alteration typically costs £3,750–£8,250 for a typical knock-through with steel beam, including VAT at 20% (standard rate). The guide for Belfast reflects typical costs in Northern Ireland, roughly 14% 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 | £3,750–£8,250 |
| Higher specification | £8,250–£10,500 |
Your quote will depend mainly on:
- Flush or downstand beam
- Agreements with neighbours on shared walls
- Moving radiators, sockets and pipes
- Floor and ceiling repairs
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a structural alteration in Belfast?
Before anything is built in Belfast, we confirm which approvals apply 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.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
What we take care of:
- Building control application
- Building control sign-off
- Structural engineer’s calculations and drawings
- Steel beam supply and installation on padstones
- Temporary propping
- Written agreement with neighbours on shared walls
How long does it take?
The build itself usually takes 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 Belfast
Across Northern Ireland, bungalows and chalet bungalows are common, so loft conversions and rear extensions are popular projects.
If your home is in Belfast or close by in Newtownabbey, Lisburn and Newtownards, 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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about structural alterations in Belfast
How long does a structural alteration take in Belfast?
Typically 1 to 2 weeks on site for a typical knock-through. Design and approvals beforehand usually take 6 to 12 weeks.
What fire protection does a steel need?
Usually fire-rated plasterboard or intumescent paint, as building control requires.
Do I need planning permission for a structural alteration in Belfast?
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.
Do I need building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.
How much does a structural alteration cost in Belfast?
In Belfast, 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.