A French door is a door consisting of two door leaves placed side by side, hinged on opposite sides of the opening. Both leaves swing open — inward or outward — providing a wide opening. French doors are also called double doors or opening doors.
French door vs. single door
| Feature | French door | Single door |
|---|---|---|
| **Opening width** | 1.20 – 2.40 m | 0.70 – 1.20 m |
| **Number of leaves** | 2 | 1 |
| **Opening direction** | Both leaves to the same or opposite side | One leaf |
| **Application** | Living room, garage, terrace, shed | Bedroom, bathroom, hallway |
Types of French doors
Opening patio doors
The classic French door for a terrace connection. Both leaves swing outward or inward. Often fitted with double glazing.
Bi-fold doors
The leaves fold double when opening — handy when the swing arc of an opening door is too large. Popular for terrace and garden partitions.
Garage door with leaves
Two solid doors that swing outward. Simple and inexpensive, but requires space for the swing arc.
Interior French door
In a large hall or living room, for example between a suite or salon. Can be solid timber, glass or a combination.
Fitting a French door — key considerations
- Check the frame size — a French door requires a wide opening (minimum 1.20 m)
- Determine the swing arc — outward-opening is often better for exterior use
- Threshold — for an external door: watertight threshold or threshold-free profile
- Espagnolette lock — the inactive leaf is secured with bolts top and bottom
- Sealing — rubber seals all round for wind and watertightness
Energy performance
- For external doors, always choose low-E double glazing or better
- Pay attention to the U-value of the door (not just the glass)
- Good sealing around both leaves is crucial
Related terms
- Frame
- Sill
- Glazing
- Casement
- Espagnolette
- Sliding patio door