Bi-fold & sliding door openings · Dundee
Bi-fold & sliding door openings in Dundee
Bi-fold & sliding door openings across Dundee, designed by a structural engineer and built under a building warrant.
- Survey, design and installation in one
- Covering DD1, DD2, DD3, DD4
- Inspected before it is covered
- 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 Dundee
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.
Across Dundee, bi-fold & sliding door openings usually come up when people want more light, a better layout or a way through to a new extension. We cover the city and its surrounding districts. Whatever the reason, the beam is sized from calculations and the work is inspected before anything is covered.
Things to plan for
- Very wide openings, or ones that run close to the corner of the house, may leave too little wall for the beam to bear on. In that case the engineer may specify steel columns or a goalpost frame standing on its own foundations.
- The structural work for a typical bi-fold opening usually takes three to five working days. Doors are often made to order, so the steel goes in once opening sizes are confirmed and the doors are fitted soon after.
- 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.
- 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.
- A wide glazed opening changes the security of the back of the house. During the works the opening is boarded at night if the doors are not yet fitted, and it is worth checking the locking and glass specification of the doors you choose.
How the job runs in Dundee
Free visit
A short visit to Dundee 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 warrant
A building warrant is applied for from Dundee City Council, and work starts only once the warrant has been granted.
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.
What do bi-fold & sliding door openings cost in Dundee?
As a guide, budget £2,300–£6,350 including VAT for rear wall opening for bi-fold or sliding doors in Dundee, based on published UK cost guides adjusted for prices in Scotland (-9%).
| Job | Typical guide range | What it usually covers |
|---|---|---|
| Rear wall opening for bi-fold or sliding doors | £2,300–£6,350 | External wall opened up to about 5 m with steel, propping, cavity tray and making good (doors supplied separately) |
| Opening into a rear extension | £2,300–£6,350 | Original rear wall removed with a beam or goalpost, approvals and propping, coordinated with the extension build |
| RSJ supply and fit (single beam) | £730–£2,280 per beam | Beam supplied, delivered, lifted and packed on padstones, with propping (calculations and approval priced separately) |
| Widening an internal doorway | £910–£2,280 | Opening widened with a new lintel or short beam, approval where structural, and making good |
Figures include our approximate regional adjustment for prices in Scotland (-9%) and are rounded. How these figures are worked out.
Approvals in Dundee
Scottish rules are stricter on timing than in England: the building warrant must be in place before the wall is touched. We prepare the application with the engineer's calculations and submit it to Dundee City Council. The finished work is then certified and a completion certificate submitted for acceptance.
Scotland has no Party Wall Act. Work affecting a shared wall is governed by your title deeds and the general law, and in flats by the Tenements (Scotland) Act 2004, so it is sensible to agree the work with neighbours in writing before starting.
More in Dundee
Local questions answered
Who approves bi-fold & sliding door openings in Dundee?
Structural work in Dundee needs a building warrant from Dundee City Council, granted before work starts. We prepare and submit it with the structural engineer's calculations and arrange the inspections, so the completion paperwork follows the job.
Do you cover Dundee for bi-fold & sliding door openings?
Yes. We carry out bi-fold & sliding door openings in Dundee. Book a free survey visit and we will check the wall, arrange the engineer's calculations and send an itemised written quote.
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.
Can I have a level threshold with bi-fold doors?
Often yes, but it has to be designed. The inside floor, outside paving and drainage all need to work together so water cannot run in, usually with a drainage channel outside and the right damp-proof detail under the door frame. We look at levels at the survey and plan the threshold with the door supplier.
Do I need a steel beam for bi-fold doors?
Usually, yes. Bi-fold and sliding doors need wide openings, and in a load-bearing external wall that span is normally carried on steel. The engineer designs it for strength and stiffness, because glazed doors can stick or be damaged if the beam deflects. A small opening under light loads might only need a lintel, but that is the engineer's call.
What happens at the survey visit in Dundee?
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.