Bi-fold doors are sold both off the shelf and as custom-made products, and can be installed as either exterior or interior doors. Your options relating to sizes and configurations will vary depending on which type of door you choose.
This page focuses on custom-made exterior doors and answers common questions around standard sizes, maximum and minimum dimensions, possible configurations and more.
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To decide what size of bi-fold doors you need, you must first assess the opening the doors are going into (known as the aperture).
It’s very important to allow some room for fitting (called a fitting tolerance)—around half an inch. So, once you’ve measured up, the actual size of door you order will be the size of the opening minus the fitting tolerance on both the height and width. This applies whether you choose aluminum, vinyl or wooden bi-fold doors.
To make sure you order the right size, we recommend you hire a building professional—such as an architect, a builder or a structural engineer—to take the measurements. They will advise you on how much of the wall to replace with bi-fold doors and how much wall space to leave around the door.
However, if you want to get an initial sense of the size of door you’ll need, you must take some measurements, as per the following steps:
With a large spirit level, measure the diagonals of the opening from corner to corner, to check that the opening is level.
Measure the width of the opening at the top, bottom and middle. Measure the height on both sides and in the middle. Take the smallest measurements and deduct half an inch (the fitting tolerance) to get the size of the door you need to order.
Consider whether the doors will open in or out and make sure there will be enough space for them to do so.
It depends on the type of door.
The off-the-shelf bi-folds you’ll find in hardware stores and other similar outlets are manufactured to be installed into a particular size of opening. This means you either need to create an opening to fit your chosen door, or find a door that fits your existing opening.
Custom bi-fold doors are made to order and can be manufactured to fit virtually any size of opening. There are minimum and maximum widths and heights to consider, but otherwise you’ll encounter few size restrictions.
The following are general guidelines, and exact measurements will vary from manufacturer to manufacturer.
There are two measurements to consider.
Bi-fold doors consist of several individual door panels, known as leaves. The minimum width of a single panel will depend on the configuration you choose and whether you have an even or odd number of panels.
For even-number configurations, the minimum width of one door leaf is around 28 inches. For odd-number configurations, it’s approximately 16 inches.
Some door companies may allow you to specify panels narrower than this. However, keep in mind that having such narrow panels could make it difficult to both operate the lead door and slide the panels smoothly along their track.
Origin bi-fold door panels have minimum widths of 28 inches (even number of doors) and 15.75 inches (odd number of doors).
Technically, the narrowest set of bi-folds you can buy has two folding doors and no lead door (the main panel that opens first and contains the multi-point locking system). However, most people opt for the three-door set—a lead door and two leaves—as they are more convenient and provide better access.
Again, minimum widths vary between companies, but a three-door set of bi‑folds will have a minimum width of roughly 45–55 inches.
A three-door set of Origin bi-folds has a minimum width of 48 inches.
Your average set of bi-fold doors will have a minimum height of around 60–70 inches, depending on the manufacturer.
Although most door companies can technically make bi-folds with a much lower minimum height, the vast majority of homeowners won’t need their doors to be so short.
Origin can manufacture doors from 15.75 inches upwards—doors this size can be used as pass‑through windows.
Like with minimum width, there are two different measurements—the width of one door leaf and the width of the full set of bi-folds.
The maximum width of a single door leaf can range from 35 to 50 inches. On Origin doors, a door panel can be up to 48 inches wide.
In the US, bi-fold doors need to pass High Velocity Hurricane Zone tests, which are designed to test the doors’ ability to withstand hurricane conditions. The maximum door panel size for hurricane zones is 36 ¾ inches x 96 inches.
The maximum door panel size for non-hurricane zones is 48 inches x 118 inches.
Obviously, this depends on how many doors make up your set of bi‑folds. At Origin we don’t put a limit on the number of door panels and have manufactured door sets with 22 panels, which spanned around 65 foot.
For many bi-fold doors, the maximum height is around 95–98 inches. However, some manufacturers can offer door sets with heights of between 120 and 145 inches. These are designed to bear the extra weight that comes with the added frame material and larger panes of glass—however, the more glass the heavier the doors will be to open.
All custom-made bi-fold doors are made to measure and designed to fit a particular size of opening. However, a “standard” three-door set of bi-folds would be between:
All custom-made bi-fold doors are made to measure, and can fit unusual spaces. Manufacturers tend to be flexible, so even if you think you need doors that exceed the company’s maximum or minimum sizes, it’s always worth contacting them to discuss your options.
Origin doors are custom-made so we can accommodate all types of spaces. The size chart below is simply an overview of common sizes that our customers request—it’s not an exhaustive list!
|approximate opening (feet)|
Panels come in different sizes and depend on your chosen configuration. As explained higher up the page, they have a minimum and maximum width and height, and these measurements vary between door manufacturers.
The table below shows those minimum and maximum dimensions.
General minimum and maximum dimensions for bi-fold door panels
16 inches (odd number of doors)
28 inches (even number of doors)
This depends on the space into which you’re installing the doors. There are few limitations to the number of panels you have—the minimum is two, while there is no real maximum.
Generally, bi-fold doors that accommodate around eight panels will need another track. The way in which doors are transported for delivery means the track can be no longer than around 20 feet. Any doors larger than that will need two different tracks, which are coupled together during installation.
Since panels are available in custom sizes, manufacturers can adjust dimensions to ensure you can have the number of panels you want.
Bi-fold doors made of aluminum (rather than vinyl or wood) have the slimmest frames, as the strength of the metal means the panels can accommodate larger, heavier panes of glass and provide a much wider view as a result.
At Origin, we build our door frames using high-strength aluminum. This enables us to achieve the thinnest possible door frame while maintaining strength and security. The frames measure 3 inches front to back, while the door sashes are around 2.8 inches wide.
There are various configurations, and you can choose whether your doors fold left or right, or some left and some right.
For example, if you have a five-door set, you might choose to have two panels sliding left and three sliding right. Alternatively, you might want them all to slide the same way.
The configuration affects where the lead door is placed. This is the panel that opens first and contains the multi-point locking system. If you pick a configuration that slides two panels left and three panels right, the lead door will sit in the middle of the entire system. If the doors all slide one way, the lead door will sit either on the left or the right.
Bi-fold doors can be configured to open either inwards or outwards, depending on your preference. What this means is when the doors are folded back, the panels will either sit inside your home or open outwards onto your outdoor space.
If you have limited space inside but lots of space outside, we recommend choosing outswinging doors.
Bi-fold doors are flexible and versatile by design and fit even the most unconventional spaces, enabling lifestyles that might initially have been considered unfeasible.
There are many configurations to choose from, including corner bi-folds, which can be supplied with moving or fixed corner posts and installed into 90-degree or 135-degree spaces. Corner bi-fold doors are great for new builds and extensions in particular, allowing homeowners to enjoy a completely uninterrupted view of the outdoors.
Unusual configurations might not be more expensive, but once you begin to increase the size of the doors the price increases too. This is because it costs more for the manufacturers to build the doors as they are required to use more materials.
See typical prices for different configurations of aluminum bi-fold doors on this page.