French Doors vs Patio Doors: What's the Difference?

In UK usage, 'French doors' means a pair of hinged doors that swing open from the middle. 'Patio doors' is a broader term that also covers sliding and bi-folding systems. So all French doors are patio doors, but not all patio doors are French doors. When a supplier says 'patio door' unqualified, they usually mean sliding.

French doors give you a clear opening of the full frame width once both leaves swing back, but they need floor space in front (or outside) to open into. Sliding patio doors need no swing space but always keep at least one panel across the opening. Bi-folds concertina to one side. Where floor space is tight, sliding wins.

French doors with proper weather seals and a multi-point locking system are typically weather-rated to Class 4 water resistance — better than most sliding doors, whose track drainage is the weak point. On highly exposed elevations, French doors are usually the more robust choice.

Sliding doors have larger unbroken glass panes. French doors have a central meeting stile that interrupts the view. If the closed-state view matters (most of the UK year), that's a mark against French doors. Slim-frame French doors partially close the gap but never fully match a slider.

French doors: 1.2–2.0m openings, cottage and period properties, elevations facing prevailing weather. Sliding doors: 2.0m+ openings, contemporary extensions, situations where the closed-state view matters. Both are valid — the decision is context-driven, not fashion-driven.