Bi-fold & sliding door openings · Mid and East Antrim
Bi-fold & sliding door openings in Mid and East Antrim
Bi-fold & sliding door openings across Mid and East Antrim, designed by a structural engineer and signed off by building control.
- Price fixed in writing once scope is agreed
- Building control arranged
- Temporary works and making good included
- Free survey visit
- Engineer's calculations arranged
- Building control handled
- Fixed written price once scope is agreed
- England, Wales, mainland Scotland & NI
What bi-fold & sliding door openings involve in Mid and East Antrim
Bi-fold and sliding door openings are wide gaps formed in an external wall, usually at the back of the house, to take a run of folding or sliding glazed doors. A steel beam carries the wall, floor and roof loads above, and it is designed stiff enough that its movement does not press on the glass or stop the doors running.
Homes across Mid and East Antrim range from Victorian terraces to post-war semis and newer estates, and bi-fold & sliding door openings look different in each. We work in Larne, Carrickfergus and Ballymena and the surrounding villages. We plan the steel, the temporary support and the approvals around the building, then fix the price in writing once the scope is agreed.
What to expect
- In cavity walls a cavity tray above the new head directs any water in the cavity out through weep vents. Without it, damp can show inside above the doors, so the tray is lapped and sealed correctly as the brickwork is rebuilt.
- The house is open to the weather between taking out the wall and fitting the doors. Temporary sheeting or a boarded frame keeps rain out and the house secure, so the gap between the structural work and door fitting should be kept short.
- New glazed doors must meet the energy efficiency requirements of the building regulations, and a wide opening adds a large area of glazing to the house. The door supplier normally provides the performance data that building control needs.
- Replacing a rear window with doors in a house is usually permitted development, but front elevations, listed buildings, flats and homes where permitted development rights have been removed may need planning permission or another consent.
- 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.
From survey to sign-off in Mid and East Antrim
Free visit
A short visit to Mid and East Antrim to see the job, agree what you want and check the bearings, floors and services that affect the design.
Calculations
The engineer's calculations and a simple drawing are prepared for your opening and shared with you before anything is ordered.
Building control
A full plans application or building notice goes to Mid and East Antrim Borough Council under the Building Regulations (Northern Ireland) 2012 before work begins.
Steel in, made good
On site we prop, open up, fit and pack the steel, then fire protect, box in and plaster once the inspection is done.
How much should I budget in Mid and East Antrim?
As a guide, budget £2,150–£6,000 including VAT for rear wall opening for bi-fold or sliding doors in Mid and East 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) |
| 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) |
| Structural calculations for a beam | £220–£640 | Site measure or photos, beam and padstone design and calculations for building control |
| Opening into a rear extension | £2,150–£6,000 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
Figures include our approximate regional adjustment for prices in Northern Ireland (-14%) and are rounded. How these figures are worked out.
Building control and neighbours in Mid and East 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 Mid and East Antrim that is Mid and East Antrim Borough Council. We submit a full plans application or building notice before work starts and book the inspections.
The Party Wall etc. Act does not extend to Northern Ireland. Shared walls are dealt with under your title and the general law, so we recommend agreeing access and the work with your neighbour before it starts.
Bi-fold & sliding door openings by town
Bi-fold & sliding door openings in Mid and East Antrim: your questions
How soon can bi-fold & sliding door openings start in Mid and East Antrim?
Start dates depend on the engineer's calculations, the building control approval and any agreement needed with neighbours. We give you a realistic timetable after the survey and keep you updated as each approval comes through.
Which towns in Mid and East Antrim do you cover?
We cover towns including Carrickfergus, Ballymena and Larne, plus the villages and smaller towns around them.
Should I order my doors before the opening is made?
It helps to choose them first. The supplier's structural opening size and threshold detail feed into the steel design, so the opening is formed to suit the doors exactly. Many people order once the engineer has confirmed the opening, then time the structural work so the gap is weathered for as short a time as possible.
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.
Why does the beam need to be stiffer for glazed doors?
Because glazed doors tolerate very little movement. Every beam bends slightly under load, and with bi-folds or sliders that movement can make panels bind, tracks drag or glass crack. The engineer sets a stricter deflection limit for these openings, which often means a heavier section than strength alone would need.
Do I need a party wall agreement for bi-fold & sliding door openings in Mid and East Antrim?
There is no Party Wall Act in Northern Ireland. Your title deeds and the general law apply instead, so agree the work with your neighbour in writing before it starts.