Aluminium Bi-Fold Doors: Costs, Sizes and What to Know

Bi-fold doors fold back in a concertina to open up a whole wall to the garden — the signature feature of a modern kitchen-diner or extension. Aluminium is the material of choice thanks to its strength and slim sightlines.

How they work and sizing

Panels are hinged together and glide on a track, stacking to one or both sides. Common configurations run from 2 to 7 panels; your opening width and how you want the doors to stack determine the layout. For very large or structural openings, talk to a structural glazing specialist.

What affects the price

• Number and size of panels and overall span.
• Glass spec — thermal, solar-control or toughened safety glass (required at low level).
• Finish — dual-colour powder coating, thresholds and handles.
• Threshold type — a flush threshold for level access costs a little more.

Security and performance

Quality aluminium bi-folds use a thermal break for warmth and multi-point locking for security; look for PAS 24 where accessible. They should still meet the replacement U-value target of 1.4 W/m²K (WER Band B).

Bi-folds, sliding doors and French doors each suit different openings — a local installer will help you choose. Get free quotes and compare.

Frequently asked questions

Bi-fold or sliding doors?

Bi-folds open up almost the entire aperture; sliding doors give bigger panes and slimmer frames with a contemporary look. It comes down to view vs maximum opening.

Are bi-fold doors secure?

Well-specified aluminium bi-folds with multi-point locks and PAS 24 hardware are very secure.