How to measure
If you’re going to pay someone to install your bifold doors for you then we recommend that you use the same person to measure the opening. If they are happy to take responsibility for fitting the doors, then they should be confident of measuring the opening also. If you are planning to install them yourself then by all means you should measure them up yourself. The measuring of your doors is a key part of the process so take your time and make sure you are one hundred percent confident prior to ordering your doors.
All bi-fold & French doors open out.
To correctly measure for your new bifold doors you need to work out the size of the masons opening and the bottom track detail of the door that you will be ordering. Our garden room doors always arrive with our rebated (fully weather bottom track) option, which is sat on a 190mm external cill, this gives an overall track height of 75mm.

Only our single hinged door open inwards.
Our single hinged access doors will open into the garden room so the rebated track is positioned the other way around reducing the internal overall track height to 56mm but with a small threshold to step over as go in and out of the garden room.

Once you know which bottom track you are going to pick you can measure your opening in the following steps:
- Firstly, check the opening is square and level. Take a large spirit level and measure the cross corners of the aperture, to make sure that the opening is perfectly square and true.
- Take three measurements for the width and three measurements for the height – one at each end, and one in the middle of the opening. Deduct at least 10mm from the smallest of those measurements to get the size of the door. The tolerance is up to you, this can be determined by how level the opening is and how confident you are with your measuring. Always deduct the tolerance from the smallest of the three measurements, this will ensure there are no sizing issues when you come to install the door.
- The width and height of your bi-folding door should be the size of your masons opening, minus a fitting tolerance of between 10 and 15mm. If your opening is already formed and you can’t see set sizes on our website that suit your opening, then you will need to order a bespoke set of bi-fold doors. We can offer this service through our parent company Express Bi-Folding Doors, you can visit their website by clicking here.
- Once you know the size of the doors that you are going to order you need to think about the threshold and the bottom tracks. The total height of the bottom track is 75mm so if you want a flush internal finish with your floor running level with the track then you need the sink the bottom track of the door by 70mm beneath your finished floor level.
- Check the layout of the garden room where the door is being fitted, and make sure you order your doors opening in the direction that best suits your space. Make sure there’s room for the doors to fold outwards into the garden. Bi-fold doors generally take up less space than normal doors so it shouldn’t be an issue, but if space is a premium the doors swinging out to the garden is definitely something you should think about.
The doors are delivered fully assembled as they are all three metres or less. The doors themselves are heavy so installation will be a two-person job. As long as the opening was measured properly and you’ve purchased the correct size, you should find installation to be a relatively stress-free process, the outer frame will need fixing into position level and square and then the panels need glazing and toe and heeling correctly to ensure the doors operate correctly.
Tips
Remember to measure your door frame at three different heights, and subtract 10mm from the smallest measurement, to ensure you get the right door size when purchasing.
Summary
Bi-folding doors are a fantastic product that will transform the way you use and enjoy spending time in your garden room. Floor to ceiling glazing ensures they keep rooms light, bright and airy but with the real wow factor of being opened to create a seamless transition from inside to out. They are perfect in living rooms, kitchens, dining areas, breakfast bars, extensions, new build homes and even in commercial settings such as restaurants and bars so will add a real wow factor to your new garden room space.
Ordering from Express Bifolds Direct couldn’t be easier so measure up your home today and pick out the perfect sized bifold door that will be delivered direct to your home within a matter of days.