Bi-fold & sliding door openings · Antrim
Bi-fold & sliding door openings in Antrim
Steelwork, approvals and making good for bi-fold & sliding door openings in Antrim and nearby.
- Itemised written quote
- Beam sized by a structural engineer
- Covering Antrim and nearby
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
Bi-fold & sliding door openings in Antrim: how it works
We cover bi-fold & sliding door openings in Antrim (BT41) and the streets around it. We also cover the surrounding towns and villages in Antrim and Newtownabbey. Each job is designed by a structural engineer and approved through Antrim and Newtownabbey Borough Council before work begins.
We coordinate the structure with your door supplier's sizes, so the finished opening matches the frame. The survey visit, structural calculations from a qualified engineer, building control, propping, steel, cavity trays, weather protection while the wall is open and making good are all covered in one itemised written quote.
Key points for your project
- Width, what sits above, whether columns or a goalpost are needed, outer leaf support, threshold works and how much brickwork needs matching all affect the price. The doors themselves are normally supplied separately unless agreed otherwise.
- Both leaves of a cavity wall need support over the opening. Depending on the design, the outer brickwork may sit on a plate fixed to the beam or on a separate external lintel, and the engineer specifies which suits the loads and the look.
- Glazed doors need a stiffer beam than a plain opening of the same width. If the steel bends even slightly under load, folding panels can bind, sliders can stick and glass can be stressed, so the engineer sets a tighter deflection limit for door openings.
- Level or flush thresholds are popular with bi-fold doors, but the floor inside and the patio outside need planning together. Drainage at the threshold and a proper damp-proof detail stop water running in when the outside is close to floor level.
- New brickwork at the reveals and above the opening should match the existing in colour, size and bond. Sound bricks from the wall being removed are often cleaned and reused, and the mortar colour is matched as closely as possible.
What happens, step by step
Survey in Antrim
We visit, look at the wall and what sits above it, measure the opening and note services, access and how the steel can be brought in.
Engineer's design
A structural engineer sizes the beam, padstones and any posts, and sets out the temporary support needed while the wall is out.
Building control
A full plans application or building notice goes to Antrim and Newtownabbey Borough Council under the Building Regulations (Northern Ireland) 2012 before work begins.
Install and sign-off
Props go in, the opening is formed, the steel is set and packed, building control inspects it, and we make good.
How much should I budget in Antrim?
As a guide, budget £2,150–£6,000 including VAT for rear wall opening for bi-fold or sliding doors in Antrim, based on published UK cost guides adjusted for prices in Northern Ireland (-14%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Rear wall opening for bi-fold or sliding doors | £2,150–£6,000 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Lintel replacement | £340–£1,030 per lintel | Propping, removing the old lintel, new lintel set on beds and brickwork made good |
| Steel goalpost frame | £1,700–£5,150 | Two posts and a beam bolted as a frame, pad foundations, base plates and fitting |
| RSJ supply and fit (single beam) | £690–£2,150 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.
Building rules for Antrim
In Northern Ireland, structural work comes under the Building Regulations (Northern Ireland) 2012 and is approved by the local council's building control. For Antrim that is Antrim and Newtownabbey Borough Council. We submit a full plans application or building notice before work starts and book the inspections.
Northern Ireland has no Party Wall Act, so there is no statutory notice to serve. Where the steel bears into a shared wall, the title deeds and the general law apply, and agreeing the work with your neighbour in writing first is good practice.
Bi-fold & sliding door openings near Antrim
- Ballymena 10.4 mi
- Newtownabbey 12.7 mi
- Lisburn 15.1 mi
- Magherafelt 16.1 mi
- Carrickfergus 16.2 mi
- Castlereagh 16.4 mi
Bi-fold & sliding door openings in Antrim: your questions
What happens at the survey visit in Antrim?
We look at the wall, the floor and ceiling either side and what sits above, measure the opening you want, and note cables, pipes and access for the steel. It usually takes under an hour and there is no charge.
Can I stay at home while the work is done in Antrim?
Usually, yes. The work area is screened and floors are protected. The rooms either side of the opening are out of action for a few days, and there is some noise and dust while the masonry comes out.
Do I need planning permission for bi-fold doors?
Usually not for a rear opening in a house, as this generally falls within permitted development. Planning or another consent may be needed for front elevations, flats, listed buildings, conservation areas with extra controls, or homes where permitted development rights have been removed. We flag this at survey so you can check before work is booked.
What does a bi-fold opening quote include?
Our itemised written quote covers the survey, calculations, building control, propping, removing the wall, steel and padstones, outer leaf support, cavity trays and closers, temporary weather protection and making good. Doors, threshold drainage and patio work are shown separately unless agreed. The price is fixed in writing once the opening size and specification are agreed.
How wide can a bi-fold door opening be?
There is no fixed limit, as it depends on the loads above and what the beam can bear on. The engineer designs the steel and, for very wide openings or ones near a corner, may specify columns or a goalpost frame. The door system's own maximum panel sizes and configurations also need checking.