Bi-folding doors measuring example

No two houses are the same, and different people need different size doors. When it comes to ordering, most bi-folding doors are made-to-measure, so getting the right sizes is essential. And that’s the great thing about them – they’re flexible and can be made truly bespoke.

Actually, measuring the opening for bi-folding doors is very similar to how you’d measure patio doors, but with a few key differences. For example, when surveying you need to consider the tracking hardware at the top and the bottom of each door and the height of the threshold. But on the other hand, measuring bi-folds is the same as measuring sliding doors.

We can carry out the survey to obtain all measurements and other details needed to fit bifolding doors correctly. But if you are confident to do it yourself, or you’re a builder looking to install at a client’s building – you can use our guide.

So, how should you measure accurately before ordering your bi-folding doors?

Step 1: Measure the width outside

Measuring example width

For bi-folding doors to fit properly and work smoothly, it’s very important to have the outer frame installed level and square.

So, the first step is to take measurements outside, starting with the width. Assuming the opening is ready, you’ll need to measure side-to-side, from brickwork to brickwork, in three places. Make a note of all them, but we’ll use the smallest measurements as a base for installing the doors.

Step 2: Measure the height outside

Measuring example height

Next – measure the height and, again, take three measurements and make a note of the shortest one.

It’s important to take into account the height of the threshold you currently have, while keeping in mind what type you’ll be needing. Some bi-folding doors have low, or flush thresholds, which make access to wheelchair users and prams very easy.

Measuring accurately is important because:

  • The step over height may need to be tweaked for outwards opening doors.
  • The level transition from outside to inside is something that can be achieved.
  • Doors opening inwards and level don’t scratch the floor inside.

Step 3: Final calculations

Now you’ve measured the height, the width and have made note of the shortest measurements. The bi-folding doors will be slightly smaller than what you’ve measured, so they can fit more easily and allow clearance.

Things may get complicated here, but as a rule of thumb, ensure you deduct 10mm off the smallest width and height size.

In addition to checking all measurements when surveying, our team will also check if all walls are straight and strong enough to how the bi-folding frames.

Sometimes the opening isn’t perfectly square or rectangular, but that’s easily fixed when fitting. You can check this by measuring the diagonals from corner to corner.

What questions you’ll need to answer when contacting us?

  • Which way will the doors fold – inwards or outwards?
  • Will you want a traffic door?
  • Which way should doors fold to when opening – left, right or out from the middle?
  • What’s the floor level (allow extra space for tiles, carpets, patio slabs etc.)

If you have any questions, or need help with your bi-folding doors, just get in touch and our team will be able to assist.