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 Lisburn?
In Lisburn, 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 |
The main things that change the cost:
- What sits above the wall
- 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 Lisburn?
Here is how the rules work for a structural alteration in Northern Ireland. In Northern Ireland removing a load-bearing wall needs building control approval from the council.
Northern Ireland has no Party Wall Act. Work on shared walls relies on agreement with the neighbour and common law, so we agree the arrangements in writing before work starts.
We check this for your address before design work starts, so there are no surprises later.
What we handle
What we take care of:
- Building control sign-off
- Building control application
- Steel beam supply and installation on padstones
- Structural engineer’s calculations and drawings
- Making good, plastering and flooring repairs
- Temporary propping
How long does it take?
The build itself usually takes 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 Lisburn
Northern Ireland has many detached and semi-detached homes on generous plots, which suits single-storey rear extensions and garage conversions.
We work across Lisburn and neighbouring areas such as Belfast, Newtownabbey and Newtownards. Postcodes we cover in Lisburn include BT27 and BT28.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 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 Lisburn
How long does a knock-through take?
Usually 1 to 2 weeks on site, plus a few days for plastering to dry.
Can the beam be hidden?
Often, by setting it within the ceiling depth. It depends on the joists and span.
Do I need planning permission for a structural alteration in Lisburn?
In Northern Ireland removing a load-bearing wall needs building control approval from the council.
Do you build structural alterations in Lisburn?
Yes. We build structural alterations across Lisburn, including postcodes BT27 and BT28. Every project starts with a free home visit.
How much does a structural alteration cost in Lisburn?
In Lisburn, 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 building regulations approval?
Yes. Removing a load-bearing wall is building work that needs approval, with calculations for the beam.