A Guide to Bi-fold Doors

Quick links:

• What are bi-fold doors?
• Why homeowners choose bi-fold doors
• What to think about when buying bi-fold doors
• How to tell you’re buying high-quality bi-fold doors
• Installation

What are bi-fold doors?

Bi-fold doors have several panels that fold together and slide off to the side. When fully opened, there’s nothing blocking your view from the inside of your home to the outside. And the doors’ slim-line frames means you still have a great view even when the doors are closed.

The panels consist of glass panes within frames made of either aluminum, timber or vinyl. All Origin’s bi-fold doors have aluminum frames.

Bi-fold doors are also known as:

• sliding glass doors
• folding glass doors
• folding glass walls
• foldable doors
• concertina doors

They look like this:

Why homeowners choose bi-fold doors

• Excellent thermal efficiency and insulation
• Choice of flush or weathered thresholds
• Protection from hurricanes
• Effective safety features
• Customization to suit your tastes and space
• Easy to maintain

What to think about when buying bi-fold doors

Size

While there are minimum and maximum heights and widths for bi-fold doors, usually it’s a case of making the doors to order, to fit the size of opening you’ve decided on. Read more about measuring your space to establish what size doors you need here.

The standard height of one bi-fold door is usually between 80 and 96 inches.

The following sizes are those most commonly requested by Origin customers:

Color

You’ll usually have an extensive choice of colors. Depending on the manufacturer, you might also have the option of dual colors (one color on the outside of the door, another on the inside) and effects such as wood grain. Most manufacturers or door retailers will be able to provide small samples of colors to help you decide.

The most popular colors tend to be:

Read about Origin’s color options here and download our popular colors guide here.

Thresholds

You have the choice of a weathered or non-weathered threshold:

• With a non-weathered threshold—which is completely flush with the floor—there’s no step or lip, leaving your path outside completely unrestricted
• A weathered threshold has a small upstand—only 0.6 inches high—but provides better protection against the 

Diagram of a non-weathered threshold

Diagram of a weathered threshold

Read more about bi-fold door thresholds and their advantages here.

Thermal efficiency and insulation

The best bi-fold doors are incredibly energy efficient, designed to prevent heat escaping your home and cold air finding its way in.

Look for the Energy Star certification, which tells you that the doors meet strict energy performance standards.

U-factors are used to measure the energy efficiency of bi-fold doors. The lower the U-factor, the better the doors are at restricting heat flow and providing insulation. Ensure that you are viewing the U-factor of the overall doors system and not just the center pane U-factor.

Origin’s bi-fold doors have U-factors of 0.27 (triple-glazed) and 0.34 (double-glazed). This is considered very low, and well within Energy Star’s conditions for certification.

Read more about thermal efficiency and why it matters here.

Configurations

Bi-fold doors can be configured so that:

• all panels open the same way
• some panels open one way and some the other (for example, if you have a seven-panel door, four could open to the left and three could open to the right)

You can also decide whether your doors open in or open out.

• Opening in—the doors will need space to open into, and fold back into, your home
• Opening out—the doors will open into your garden or outside space

Most people prefer the doors to open outwards as this means they don’t take up room inside.

Read more about bi-fold door configurations here.

Maintenance

While most bi-fold doors are built to last, aluminum doors in particular require very little maintenance.

Cleaning the frames and glass panels with warm, soapy water and a non-abrasive cloth should be enough to keep them looking new. Click here for more useful advice on how best to clean bi-fold doors.

Protection from hurricanes

If you live in a region which is prone to hurricanes, it’s wise to install bi-fold doors which have passed Florida’s HVHZ (High Velocity Hurricane Zone) testing.

Without compromising on thermal efficiency, these doors use locking mechanisms that protect your home against:

• very strong wind and rain
• debris
• extremes in air pressure that can cause buildings to collapse

Customization to suit your tastes and space

Most bi-fold doors can be customized to your exact needs and preferences. You have a wide choice of colors, hardware (such as door handles and security features), configurations and sizes.

Read more on bi-fold door sizes and configurations here.

Effective safety features

Safety and security are high priorities when deciding which bi-fold doors to buy. Look for doors with the following safety features:

• Multi-point locking systems
• High-security hinges and handles
• Finger-safe gaskets
• Low thresholds suitable for disabled access
• Strong magnetic keeps to hold the door firmly in place

Read more on safety and security for bi-fold doors here.

How to tell you’re buying high-quality bi-fold doors

Before you buy, use the following questions as a checklist:

1. How many companies are involved in the manufacturing process?

It’s often the case—though not always—that the more companies involved in manufacturing the complete door system, the lower the quality. Because each company will have different standards and manufacturing methods, the quality of their products can vary.

2. Have the doors passed quality tests and ratings?

Standards established through hurricane testing and energy efficiency ratings demonstrate that the quality of the bi-fold system has been assessed by an independent, neutral party.

3. What are the doors made of?

Bi-fold door frames are usually made of aluminum, timber or vinyl. Aluminum is the more durable of the three and—unlike timber or vinyl—won’t warp. (Warping tends to be the main cause of leaks and drafts.) Aluminum will also stay in its best condition for much longer than other types of doors.

The aluminum used to make bi-fold doors is either:

• made from scrap
• produced from prime billets (i.e. hasn’t been used before)

Because scrap aluminum is re-melted, it doesn’t have the same level of purity as aluminum made from prime billets. This will be evident in the powder-coated finish, which is likely to have some imperfections and look and feel less smooth.

For the best-quality bi-fold doors, look for a product made from the highest-grade aluminum.

Read more on how aluminum compares to other bi-fold door materials here.

4. Do individual components appear to be well made?

The quality of individual components such as handles and locks contributes significantly to the doors’ overall quality. Make sure they:

• have been cycle-tested for strength and security
• are covered by the warranty

5. What is the U-factor of the door system?

U-factor is explained here. The lower the U-factor the better.

6. Is there a long warranty?

A long warranty—say, 10 years—is the ultimate sign of a high-quality door system.

Always examine what the warranty covers, as some manufacturers provide a long warranty on the powder-coating finish but not the doors as a whole.

Installation

We don’t recommend trying to install bi-fold doors yourself. Most bi-fold doors are custom-made products that must be fitted in a very specific way, by installers with the appropriate training. Installing these doors without a full understanding of how they work could lead to problems later.

At Origin, we work with accredited partners who are fully trained in how to install our products. This way, you know your bi-fold doors have been fitted correctly.

Read more about installation and delivery here and download Origin’s installation guide here.

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