French doors are a popular choice for many households. Want to know more about what a French door is and more? Here is your guide to French doors!

Table of contents

What are French doors?

French doors are a pair of doors with hinges that allow them to open outwards. They’re usually manufactured with glass panes that typically extend the length of the door. Great for working as both an entrance/exit and a natural light source.

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Cost of French Doors

The average cost of your typical French doors can be anything between £1000 and £3500. The cost of French doors can depend on various factors. Not just the material it is made from or how many you want.

You will need to consider whether you’re creating a brand new opening, converting an existing doorway or window and whether enlarging an existing window or doorway is required for the French door. You will also need to consider the labour costs.

French door styles

Also known as double doors or patio doors, French doors offer a dramatic effect that features a lot of glazing. Due to this, French doors are often used between dining rooms and living rooms. Though they’re also commonly used as an entry/exit to and from patio areas (hence the alternate name).

French doors are designed with functionality and style in mind. They’re slim, sitting within smooth running mechanisms for a perfect finish and optimal thermal performance.

White external French door seen from inside

What to look for when buying French doors

Choosing a French door means looking at more than where you want to put it and what type you want. Here are some things to look out for and help you define your decision when choosing French doors.


The chosen material for a French door will depend on your needs. PVC French doors and aluminium French doors are typically sought after, though solid wood and engineered wood French doors are also available.

However, wooden French doors are often avoided as wood absorbs moisture and changes temperature. This, over time, can cause changes to the appearance of the door. Including allowing gaps to form which can let in draughts.

The positives of this are that engineered wooden doors are designed to withstand the elements. This is thanks to the material being manufactured from different planks of wood, then surrounded by a veneer. In simpler terms, aesthetically pleasing wood on the outer side of the doors and cheaper wood for the interior. In turn, this makes for an authentic solid wood door appearance. It also means warping effects are reduced, as each varying piece of wood will warp differently.

Regardless of the type of wood, you will need to maintain it to make it last. Sometimes, like re-painting or finishing, a wooden door will require a clean frame before doing so to ensure a better-looking finish.

UPVC French doors on the other hand are more commonly used in today’s modern age. Easy to clean, less hassle to maintain and better performing against the elements, it’s no wonder. However, the material is not without its challenges. uPVC may be easier to maintain, but it doesn’t have the strength that other materials hold. So you may need to opt for a thicker frame to accommodate the chosen amount of glass for your project.

Aluminium French doors are a growing choice due to their strength and further options for flush framing. Thinner frames also mean more glass can be installed, meaning more natural light can be let into the home. On top of that, you can enjoy a better view of the outdoors thanks to a wider windowpane.

Closed external French door


Colour choice is of course a key factor in the appearance of French doors. Today modern French doors are no longer restricted to traditional white. Instead, you can now have a variety of different colours. This includes black, grey or even no colour at all if you desire wooden French doors with the existing material’s appearance.

PVC doors commonly have foil or colour finishes. Grained textures are possible with this type of material as well. Aluminium on the other hand typically comes with tough powder-coated colours, woodgrain or metallic finishes. These can be easily cleaned and maintained.

Crystal uPVC French Door Grey Left Handed with Clear Glazing & Cill


Modern French doors come with an array of security choices in the form of locking points. Most commonly you can find four, though there are models with five or even eight. This will depend on the level of security desired.

You can find the security rating of the door on the door cylinder. French doors will usually have high-security cylinders built in.

Particular security features include the use of internal glazing beats to prevent glass removal from the outside, as well as the high-security cylinders designed to prevent drilling, picking and snapping.

It’s also worth noting adding mortice sash locks or mortice security bolts could be beneficial for added security. Laminated glass is also preferable.

House with a Door Superstore Avondale External French Door


Insulation might be an afterthought, but French doors can be a key feature for ensuring the warmth stays in your property. It’s also good for helping lower the cost of heating bills and encouraging energy efficiency.

Aluminium is ideal as it can come with an insulated profile. This creates a polyamide thermal break, ultimately reducing cold bridging. Alternatively, uPVC profiles typically have multiples of chambers and cores that support frame energy efficiency. It improves the strength of the door too!

As a main component of the French doors, glass combined with either material can provide energy efficiency.

Dining room with a French door seen in the background

Standard French door sizes in the UK

Our customers often ask:

What is the standard French door size in the UK?

The good news is that there are indeed common door sizes in the UK when it comes to French doors. The typical French door width options are 120cm, 150cm and 180cm. The standard French door height is 2.1m (around 82″). Although there are varying types, these are your more appropriate French door dimensions for installation.

French door size chart

Size (mm)Size (cm}Size (ft)

Now that you know what sizes are available on the market, how do you measure a French door for a patio?

That’s what we’re going to look at next.

How to measure for French doors

Measuring correctly for a French door is absolutely crucial, so you can purchase the correct size door.

The thing is:

Too big, and it won’t fit. You’ll have to trim it, and that might jeopardise the door’s structural integrity. Too little, and you’ll be left with ugly, uncomfortable gaps you’ll struggle to fill.

So, take your time and don’t rush when getting the measurements. Also, measure at least twice, just to be on the safe side. You’ll thank us later!


French door measurements should be taken from the inside and from the brickwork – not the existing frame or door. Start with the width, measuring at the top, bottom and middle of the opening. This way, you’ll get the most accurate measurements.

Follow this with the height at the left side, right side and middle of the frame. Once again, this method will give you the most accurate measurements. Finally, measure the jamb from the back of the exterior trim to the back of the interior trim. This can ensure the door is flush with the wall.

Round up the height and width measurements. You should have a larger measurement which will need to be noted. However, if there is a large difference between the rounded-up measurements, this means the frame is not plumb and will likely need changing or re-alignment with shims.

If you’re replacing an existing French door, you can also measure it once you’ve removed it from the hinges. However, that’s not necessary.

Final thoughts

With the abundance of choices now available, design possibilities are endless. Check out available French doors to see what you can do to bring more natural light into your property and add a unique entrance/exitway to your home.

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