Patio Doors Sizes & How To Measure For Them?

Patio doors rank high among the most popular type of external doors on the market. They can make your home feel bigger and brighter, and they may even add value to your home. The first thing you need to consider when choosing new patio doors is the size. You’ll need to know if there’s a standard size available and the relative sizes of french doors and sliding doors. Most importantly, you’ll need to know how to measure up for your new doors. So, if you’re looking to learn more about what size patio doors you might need, here’s our quick guide on sizing and measuring patio doors.

Are patio doors standard sizes?

When you’re purchasing new doors, there is always a temptation to find an ‘average size’ and order that. The problem is, when it comes to patio doors, there is no standard size. With your average internal door, you have a small margin for error. Err on the side of caution, buy one that’s a little too big and you can simply shave a few centimeters from the edges. And voila, your door fits in its frame. With patio doors, this isn’t possible. They need to fit exactly, in order to provide the highest security and heat insulation possible. The frames are usually an integral part of a patio door set up and you won’t be able to adjust the doors. When it comes to patio doors, you need to find a set that will definitely fit your home right from the start.

What sizes are patio doors?

Although there is no standard size for patio doors, you don’t need to worry about picking from an infinite selection either. The majority of door openings will sit within a limited range (though there are always bespoke options if you struggle to find an exact fit). The majority of doors will be the same height, around 2088mm, but the widths may vary. This difference will be even bigger between french patio doors and sliding doors.

External french door sizes

French doors are almost always sold in pairs, and the stated width is the size of the two doors combined. The majority will be between 1400mm and 1700mm. That’s the size of the doors, not including the frame (or jamb) which adds around 150mm to the width (about 75mm on either side). You can get pairs of doors that are as narrow as 900mm or as wide as 1900mm, if you need them but this is pretty much your limit. If the doors get any wider, that will affect the load acting on the hinges, and the opening circle of the door will be too wide. Make them any narrower and you won’t be able to fit the two doors together comfortably. Of course, if you’re buying a set of doors with the frame included, then you need to add 150mm to those measurements. For even wider openings than that, you may want to consider adding sidelights around your french doors. For taller spaces, consider transoms. Sidelights are slim window panels that sit at the side of the door and reach the full height. Transoms are similar, long, thin windows but they are placed above the doors rather than beside. Transoms and sidelights are very popular for using with french doors, because they can be very decorative.  If you have particularly decadent set of doors, you can often find transoms or sidelights that echo their style.

External sliding door sizes

Sliding patio doors tend to work better in larger openings. Their big, clear, panes of glass make sliding doors the perfect choice when you really want to soak your home in sunshine. Our range of sliding doors at Doors & More runs from 1588mm wide, right through to 4776mm. This includes at least one stationary panel and one sliding panel, plus the frame measurements. Because of the mechanism that works the door will vary in size. It will depend on the material the frame is made from and the type of frame, so it is hard to give an ‘average’ size. Whilst sidelights and transoms can be used around sliding doors, they are generally unnecessary. This is because they offer far more flexibility in size as standard. If you do want to substantially increase the amount of light let in by a set of sliding doors, the best way is to add a couple of extra stationary panels.

Patio doors dimensions

Most patio doors are sold in full sets, with the door jamb/frame included. This is standard to help make them easier to fit and replace.

Extra wide patio doors

If you are looking to really maximise the amount of light entering your home, you may consider buying some extra wide doors. Most manufacturers will have a couple of wider options, though these may be limited as they can affect the workings of the doors. You can also consider investing in a set of bespoke doors, to give you ultimate control over your patio entrance (though there will still be limitations due to functionality). But if you really want to open up that space and let the sunlight soak in, an excellent option is adding extra panels around the doors.

How to measure for patio doors?

Regardless of whether you go for sliding doors or french doors, by now you’ll hopefully realise that your doors need to fit correctly. And that the only way to ensure this is to measure up accurately before you even start looking. You will need to know the size of what is called the ‘rough opening’. This is the opening your doors sit in. It doesn’t include any frames or mouldings. As most people won’t have the luxury of being able to completely remove their old door before they measure for a new one, make sure your measurements include the door frame. Remember they need to cover the whole opening.

Step 1 - Prepare

Grab a tape measure, pen and pencil. If you can grab someone else to give you a hand that’s great as this will help you get an accurate reading. It could also help to quickly sketch out the door, so you know where all your measurements are taken from.

Step 2 - Measure the width

Take three measurements. One at the top, one at the bottom and one in the middle of the opening. If there is any variation in these numbers, make sure you look for a door that will fit in the smallest part. With external openings, the numbers should be very similar, but any slight differences can be addressed using shims or similar.

Step 3 - Measure the height of the opening

Again, take three measurements. One on the right, one on the left and one in the centre. Measure all the way down to the ‘sub-floor’ - that’s concrete that the sill of the door sits on.

Step 4 - Measure everything again

Taking the time to be extra careful at this point can save you a lot of hassle in the long term.

Step 5 - Adjust the measurements

Take 10mm from both measurements to allow for trim, casings etc, that are not necessarily visible. This leaves you with your final numbers. With these measurements in hand you should have everything you need to order a new set of patio doors. Whether you choose bright, open sliding doors, or classically stylish french doors, installing a set of patio doors in your home is a wonderful way to welcome the fresh green beauty of your garden, into the comfy sanctuary of your home. Measuring up and choosing sizes is only the first step on the journey to a more open, airy and brighter home. Check out our range of patio door options to see what kind of style impact you can make on your interior too.