You are using an outdated browser. Please upgrade your browser to improve your experience.

JavaScript seems to be disabled in your browser. You must have JavaScript enabled in your browser to utilize the functionality of this website.

skip to main content

Origin Doors

< Advice Centre

Bi-fold door features—what they are and how they can benefit your home

Deciding whether to install bi-fold doors means understanding exactly how they will benefit your home.

Bi-folds have many features that set them apart from other doors. We cover the main ones here:

Glazing

By design, bi-fold doors consist of thin frames (aluminum, wood, vinyl) enclosing large panes of glass. Because they are mostly glass, only certain types of glass are suitable.

When buying bi-fold doors you’ll need to make decisions around the specific kind of glass you want. This means choosing between:

  • double glazing or triple glazing
  • toughened or laminated safety glass
  • standard glass or noise reduction glass
  • standard glass or low-E glass (glass with an energy efficient coating)
  • glass with or without integral blinds

Double glazing and triple glazing

Bi-fold doors typically come with double glazing as standard, but you’ll have the option to substitute it with triple glazing if you prefer.

They both work the same way. Panes of glass enclose a sealed cavity (or cavities) filled with air or a noble gas such as argon or krypton. This system stops heat transferring from the inside of the home to the outside—or cold air going the other way—keeping the room well insulated.

Obviously, triple glazing has the advantage of an extra pane. So not only is it more energy efficient than double glazing, it’s more secure and better at stifling noise from outside too. That’s before you consider swapping regular glass for safety glass or noise reduction glass (see both sections below).

Read more about choosing between double and triple glazing here

Safety glass

Because some glass breaks easily, folding doors must incorporate strengthened safety glazing. Building codes usually specify this. The safety glass is both to keep the home secure and to protect the people inside if the glass does break.

Safety glazing can mean either toughened glass (also called tempered glass) or laminated glass.

Toughened glass

Laminated glass

  • Made by heating ordinary glass in a very hot furnace then cooling it quickly
  • Hardens the glass and makes it up to five times stronger
  • Less likely to break if struck or exposed to extreme temperatures
  • If it does break, shatters into small, blunt pieces rather than long, sharp shards
  • Made by sandwiching a plastic interlayer between two thin panes of glass under heat and pressure
  • The plastic acts as a glue that bonds the two panes together
  • If the glass breaks, the tough interlayer holds it in place—there’s no hole or shattering into pieces on the floor

Both types of glass are designed to be shatterproof, meaning when they do break there’s less chance of someone cutting themselves on sharp fragments.

While you’ll find plenty of bi-fold doors with toughened glass, laminated glass is typically the better option. This is because it:

  • has a layered structure that makes it thicker than toughened glass, meaning it’s more resistant to shock and damage
  • provides more insulation
  • is better at reducing noise (see below)

On the other hand, laminated glass is heavier, so you might find that only bi-fold doors with aluminum frames can support the weight. It’s also more expensive than toughened glass.

Noise reduction glass

On account of their design—two or three panes of glass enclosing one or more plastic interlayers—double and triple glazing are very good at blocking out noise, whatever type of glass is used.

It becomes more effective, however, when it uses laminated glass. This is because laminated glass:

  • disrupts the noise by changing its frequency
  • reflects the sound back towards where it came from
  • absorbs the noise within the glass

Using glass of different thicknesses on each side of the plastic interlayer(s) will stifle the sound even further. Most laminated glass is capable of reducing the sound by up to 10 decibels, which, to the human ear, sounds around 50% quieter.

Low-emissivity (low-E) glass

Bi-fold door glass can be treated with an extremely thin, transparent coating that stops heat escaping through it. This is known as low-emissivity (low-E) glass, and is significantly more energy efficient than ordinary glass.

The special coating also limits how much ultraviolet (UV) and infrared light can travel through the glass and into the home. By blocking these types of natural light, it makes rooms less stifling in hot weather, or uncomfortably cold in winter.

Thermal breaks

Bi-fold doors are designed to be very efficient in stopping heat escaping your home and cold air finding its way in. This is called thermal efficiency.

The thermal efficiency of folding door systems is measured by something called the U-factor. This figure measures the rate at which heat is transferred through one square meter of material, and tells you how effective the doors are at restricting heat flow and providing insulation. The lower the U-factor, the more energy efficient the doors are.

The U-factor is particularly important for aluminum bi-fold doors. As aluminum is a natural conductor, it can draw heat out of a room or in from outside. To prevent this, they are fitted with a thermal break—a thermally efficient component that separates the interior and exterior parts of the door.

Read more about thermal efficiency of bi-fold doors here

Weathered and non-weathered thresholds

The threshold is the bottom part of the doors—the track along which the doors slide to give them their smooth operation. With bi-fold doors, you usually have the choice of a weathered or non-weathered threshold.

  • A non-weathered (level) threshold is completely flush with the floor, meaning there’s no step or lip. Some people like their bi-fold patio doors to be totally level and not disturb the path between the inside of the home and the outdoor living space. A level threshold can also be safer, as there’s no risk of anyone tripping. However, level thresholds aren’t guaranteed to keep water out.
  • A weathered threshold is slightly raised off the floor, and is designed to provide better protection against rainwater and inclement weather. We recommend weathered thresholds for external use.

Read more about bi-fold door thresholds here

Security features—locking systems, handles and bi-fold door hardware

Locks and locking systems

Most bi-fold doors come with multi-point locking systems as standard. These systems secure the doors at various points around the frame and track.

You’ll find that different bi-fold door companies offer different kinds of systems—some with five points, six points or, like Origin, eight points.

A 5-point system, for example, typically has two hook bolts at the top and bottom of the frame, a combination of latch and deadbolt in the middle of the door, plus a pair of additional points of locking around the door frame.

An 8-point system has the same, but with extra shoot bolts at the top and bottom of the track and additional security hooks.

Door handles

The handle was once considered one of a door’s weakest and most vulnerable pieces of hardware. Today’s bi-fold doors, however, tend to be equipped with strong, heavy duty metal lever handles which are designed to withstand brute force attacks from housebreakers.

When deciding on handles and hardware for your bi-fold or sliding doors, you’ll generally have a choice of styles, colors and materials. Style and color is more a matter of personal taste, but when picking a material you should consider what will stand the best chance of withstanding regular use and the effects of the weather outside.

Stainless steel, chrome and nickel are all very good bi-fold hardware options, as they fare very well in all weathers and need very little maintenance.

Read more about bi-fold door safety and security here

Child-safety features

Finger-safe gaskets

If there are children in your household, you want to be sure that opening and closing your bi-fold won’t put their safety at risk in any way.

Young children do have a habit of putting their fingers in places they shouldn’t, so look for bi-fold doors that come with finger-safe, child-proof gaskets. These are designed to provide soft cushioning should a young child get their fingers caught between the sliding door panels.

Magnetic catches

Perhaps the main reason for fitting bi-fold doors is the chance to fold them back and open them up. Bi-folds have a magnetic catch (also called a magnetic keep) that holds them securely in place while the doors are open.

Hurricane protection

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

Also make sure you choose doors with laminated glass and a weathered threshold.

Configurations—including corner options

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 six-panel door, three 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 yard or outside space

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

However, there’s also the option to install corner bi-folds. Doing this means taking away one complete wall or window and an adjacent wall, and replacing that section of space with bi-fold doors.

Read more about installing corner bi-fold doors here

Read more about other bi-fold door configurations here

Color options

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:

  • White
  • Black
  • Bronze
  • Wood grain

Read more about bi-fold door colors here

Download the Origin Bi-Fold Door brochure here

Share this article on social media: