French doors are one of the easiest ways to bring light and space into a home. The name covers more than most people expect: a French door is really any door glazed over most of its height, and it can be a single door or a pair, fitted inside the house or opening onto the garden. Here's what they are, how internal and external differ, and how to choose the right timber, glazing and hardware.
What are French doors?
A French door is a door made largely of glass — glazed over most or all of its height, rather than filled with solid timber panels. That's the whole idea: light passes through the door instead of stopping at it.
From there, two things vary. A French door can be a single door — one fully glazed leaf in a standard opening — or a pair, two leaves that open from the centre to give a wide, unobstructed opening. And it can be fitted internally, dividing two rooms, or externally, opening onto a patio or garden. The term covers all four combinations, which is why French doors turn up in very different contexts.
Single or a pair?
| Single French door | A pair (double) | |
|---|---|---|
| Opening | A standard door-width opening | A wide opening — both leaves swing clear |
| Best for | Bringing light into a normal doorway | Connecting two rooms, or opening a wall onto the garden |
| Feel | Neat and simple | Generous — two rooms read as one when open |
Internal French doors
Indoors, French doors divide rooms without closing them off. A glazed pair between a living room and dining room lets light travel through the house and makes both rooms feel larger, while still giving you the option to shut the space for quiet. A single glazed door does the same job in a standard doorway — useful for a study, or a dark inner hallway that can borrow light from a brighter room.
Internal doors are lighter and built for a controlled indoor environment. Ours come in oak, walnut and primed finishes ready to paint, as pairs and singles — see our internal French doors.
External French doors
Outdoors, a French door opens a room onto a patio or garden. It has to do everything an internal one does and take the weather too, so it's built heavier — with a double-glazed sealed unit, toughened safety glass, weather seals and proper locking.
Here too it can be a single fully glazed door or a pair. Our external French doors are glazed timber doors made for outdoor use, in oak and hardwood. If you want a single glazed door rather than a pair, browse our glazed external doors.
One thing to be clear about: don't fit an internal door outside. It isn't built for rain, wind or security, and it will warp and let you down.
Glazing options
How much you see through the glass is a choice — and it works differently inside and out.
Inside, clear glazing gives the most light and an open view between rooms. Obscured or frosted glass keeps the daylight but blurs the view, which suits a study or a door off a hallway. Decorative and leaded designs add character to a period home.
Outside, the glazing is a double-glazed sealed unit with toughened safety glass, so you keep the warmth and the security along with the light. Obscured glass works here too on a street-facing door, and leaded designs suit a period property.
Timber, finishes and hardware
Inside, oak is the classic choice — warm, characterful, and it takes an oil beautifully. Walnut is darker and richer, and primed doors arrive ready for you to paint. See our oak internal doors, and finish them with door furniture in a matching finish.
Outside, the timber has to handle the weather. Our oak external doors and hard-wearing hardwood external doors are built for it, and they need treating with an exterior oil to stay protected. Finish them with external door hardware — fittings made for outdoor use, so they don't corrode.
Whichever you choose, matching the finish across the handles, hinges and latches is what makes a door look considered rather than ordinary.
Fitting and looking after them
A pair has to be hung square or the two leaves won't meet cleanly in the middle, so the fitting matters — especially outside, where the seal against the weather depends on it. After that they're easy to live with: clean the glass, wipe the timber down, and check the hinges and locks now and then. An external timber door also needs its finish refreshing about once a year to stay protected.
Frequently asked questions
What are French doors?
A door glazed over most of its height, so light passes through it rather than stopping at it. A French door can be a single fully glazed leaf or a pair that opens from the centre, and it can be fitted internally or externally.
Are French doors single or double?
They can be either. A single French door is one fully glazed leaf in a standard opening; a pair is two leaves opening from the centre, which gives a much wider opening.
What's the difference between internal and external French doors?
External French doors are built heavier, with a double-glazed sealed unit, toughened safety glass, weather seals and proper locking, so they can take the weather and keep the home secure. Internal ones are lighter and made for dividing rooms indoors.
Can I use internal French doors outside?
No. Internal doors aren't built for weather or security — they'll warp, let in draughts and fail. Use a door made for external use.
Are French doors draughty?
A well-made, properly fitted door shouldn't be. Draughts usually come from a poor fit or a seal that has perished over time, and both are fixable. An external door should have weather seals as standard.
Are French doors secure?
An external French door should have multipoint locking and toughened glass in a double-glazed unit. Specified that way, it's as secure as a solid door — with far more daylight.
Whether you're opening up two rooms or a wall onto the garden, a French door is one of the simplest ways to bring light and space into a home. Browse our internal French doors and external French doors — and if you'd like help working out what suits your opening, our team is happy to advise.
Related reads
| External doors with glass: fully glazed vs half glazed | How much glass is right for an external opening. |
| Can you use internal doors outside? | Why an internal door won't survive outdoors. |
| Maintaining your internal & external doors | Keep the glass, timber and hardware in good order. |
