The Ultimate Buyers’ Guide To Folding Doors


Open Your Space With Folding Doors

As much as we need shelter and homes, we also long to be more connected with nature. As much as we appreciate shelter from the wind and rain, we enjoy a fresh draft on a nice day. As much as we need the shade to protect us from the sun’s heat, we don’t want to be enclosed in darkness.

If you really think about it, windows and doors are one of the main things that separate a house from a medieval hovel or a cave. They’re our way of keeping out the bad weather (or unwanted guests) and letting in the good weather (and invited guests).

The doors and windows to your home or business make a statement.

Small windows and strong doors are imposing; large windows and wide doors relate openness and acceptance. Many consider windows to be a sign of vulnerability. After all, they’re made out of a material that can be easily shattered. As society became safer, windows became larger. Eventually, we even started to use clear window panes as doors. This is what triggered the evolution of the folding glass door.

Today, we’re going to be giving you an in-depth look at glass folding doors. Sometimes referred to as glazed folding doors, we’ll go over the differences between bi-folding doors, accordion doors, and panoramic doors. Aside from the surface differences, we’ll also be taking a deeper look into the various technical specifications that buyers and contractors should be aware of. From door frame materials, energy efficiency, security, and even hurricane-proof folding doors- we’ve got you covered.

By the time you finish reading this guide, you’ll know folding doors inside and out (pun intended). So, whether you’re a contractor looking for a creative solution for your client or a homeowner who’s looking to modernize their space and open up their home- this guide’s for you!

Folding Doors | A Look At Your Options

Installing folding doors into your new home is a big decision. It will usually involve some significant modification of your existing walls and doorways. Once installed, your new door system is going to become a permanent fixture of your home, so you want to make sure that you’re choosing the right option.

In this section, we’re going to be going over the two main styles of folding doors:

  • Bi-Fold or “Accordion” Doors
  • Panoramic Doors

While there are several other types of moving or “sliding” doors on the market, we’re going focusing specifically on the latest hi-tech folding door solutions available. These window and door systems have been developed with patented mounting technology and cutting-edge scientific solutions to create a truly impressive result.

All of these doors have one thing in common-

They’re designed to transform what would otherwise be a boring wall into a window that can be freely opened or walked through.

However, each system has their perspective history, uses, benefits, and drawbacks when compared to each other. As you’re reading and deciding what’s best for your home, make sure that you keep your home layout and individual situation in mind.

Bi-Fold Doors

Bi-Fold doors are the most common form of folding doors available. They consist of multiple glass door panels, which are held together by hinges. The door panels can be folded and arranges parallel to the doorframe. Depending on the design, they can either be folded inwards or out. In most cases, they’re folded outwards to minimize intrusion into the interior space and furniture placement. 

When all of the panels are folded to the side, they have a stacked looked. This is where the term “accordion doors” comes from. Accordion doors are actually quite different- they’re the thin, flimsy, plastic or paper-like doors that are often used as pantry doors or to provide added privacy in an interior space. However, the term is thrown around quite loosely and is sometimes used to refer to bi-folding exterior doors.


Bi-fold folding door systems work by installing the panes into a simple tracking system which runs along the top and bottom edges of the door frame. The panes are usually held on the track by a few rolling wheels or a magnetic system, which allows the doors to fold into one another easily.

The doors usually come in pairs, which is why they are called “bi-fold.” Smaller folding door systems may only have 2 or 3 pairs of folding doors per track, while larger setups may have up to 7 or 8 pairs of doors. How many panels you install in your home depends a lot on the structural integrity of the walls.

Often, some of your walls will have to be removed entirely or torn down to make space for the track setup. As you can imagine, this can severely upset the balance of your homes and could result in some unintended consequences. That’s why it’s usually best to have a professional install your bi-folding doors.

Most homeowners aren’t going to fully open all of the panels every day of the week. Because of this, many bi-fold door setups will include a primary door that functions just as a normal single-action front door would. It usually includes a typical door handle, locking system, and hinging off the existing track system.

Bi-folding doors are usually anchored on the sides and can be folded outwards from the middle. However, some systems fold all of the door panels into one side or the other. Should you wish to ventilate your room a little bit, all you need to do is open your primary door or fold half of your panes to the side. This will keep the other half of your windows in-place and make sure that too much air doesn’t get in.


  • Sturdy design.
  • Opens up rooms with more light and space.
  • The folding accordion-style design allows users to easily slide multiple door panels at once.
  • Doors can be folded outwards so that space isn’t taken up indoors.


  • Because door panels are connected in pairs, there can be more wear and tear on the tracking system.
  • More visible hardware and hinges create a more traditional look.

Panoramic Doors

Panoramic doors are a newer concept. They were originally designed to incorporate the best aspects of both sliding doors and bi-fold doors into one system. On the surface, they look almost identical to bi-fold doors; they’re tall, wide, feature all-glass panels, and can turn an entire wall into a window.

However, the main difference lies in how the glass panels are connected to each other.

In a bi-fold system, the window panes are connected in pairs and joined with a few hinges in the center. Each pair of doors/windows is designed to connect into the adjacent pair with a series of push-in locks or pins. Whenever you open your bi-fold system, you’ll be moving two panels at once.

In a panoramic folding door system, though, each door panel is separated from the others. There are no hinges that connect pairs together. Instead, each door panel has a series of built-in quick-connect hinges that can easily be separated from the next panel or re-connected in seconds. These hinges are held within the sides of the doors and are practically invisible from the front and back sides of the panels. This means you won’t see any of your standard bolt-on hinges and locking mechanisms, making for a sleeker, more modern design.


One of the main advantages of this type of door system is that they’re more durable. Because panels aren’t connected to each other when they’re moved, there isn’t as much lateral “shearing” force put on the hinges and window tracks. One of the main problems that can arise with bi-fold doors over the years is that the doors can become disconnected from the tracks. This happens for less often with a panoramic door design.

When installing panoramic folding doors, you’ll also have the option to create a primary door just as you would with a bi-fold installation. This door will operate on a swinging hinge but can be re-connected/disconnected from the main track at any time. The primary door will also contain the locking mechanism for the system. Once you lock the primary door, it will be impossible to slide open the other panels. This makes for a system that’s equally as secure as bi-fold doors.


  • Each door panel can be systematically spaced-out for superior ventilation.
  • Should one door panel malfunction, you’ll only need to replace the one instead of a pair.
  • Because door panels aren’t connected, they undergo less strain/wear and tear.
  • Fewer hinges and hardware help to create a more sleek design.


  • Can be more expensive than traditional bi-fold doors.
  • Because panels aren’t connected in pairs, each panel has to be moved individually. A full open can take a bit longer than bi-fold doors.

Technical Considerations When Buying A Folding Door System

As you can tell, both folding door systems have their benefits and drawbacks. Ultimately, the decision comes down to personal taste, preference, ease of use, and how the doors will look with the rest of your home’s interior and exterior design aspects. We’re not here to convince you to choose either one. We just want to show you what your options are.

Aside from deciding on the style of the folding door that you want, however, you’ll also want to compare the various technical specifications of each brand of door. Although panoramic doors are generally considered “more modern and high-tech,” here are some bi-fold doors that are better built than panoramic doors. When it comes to any home renovation you plan on doing, materials and specifications are everything. Fancy looks can often come with lower-than-average design if you don’t know what to look for.

In this section, we’re going to go over all of the technical features that you need to take into consideration when selecting a glazed door, accordion door, bi-fold door, or panoramic folding door system. We intend to be quite thorough with the following information as this guide is written for contractors as much as it is for the average homeowner. So, it’s okay if you don’t understand every small detail. If you have any further questions, please don’t hesitate to contact us!

Door Frame Materials

The material that you choose for your folding door frame is usually the first step you’ll take when purchasing the doors. The frame is what the casing of the door is made out of and also what holds the window panes in place. As such, it’s one of the most important aspects of door design.

Depending on the design of your home, your budget, style preference, needed durability, and ease of installation, each material has its own benefits when compared to the others. The most commonly used door frame materials are aluminum, vinyl, and wood. In some cases, steel is used, but it’s heavier and therefore not quite as common. In addition to the type of material that you choose, you’ll also want to double-check the quality of said material.



Aluminum folding doors are very common and are known for their durability. Aluminum is an incredibly popular metal for home goods and materials. It’s strength to weight ratio is incredibly high- this means that it’s both strong and lightweight, making it the perfect material for any door. Everything from aircraft to bicycles and even computer/phone cases are made with it. If you’re building large doors, then using lightweight aluminum will not only make installation easier but will also make the doors easier for the homeowner to open and close regularly.

One of the key advantages of aluminum is that it doesn’t rust. Once refined, the metal contains virtually no trace of Iron or Iron oxides which are known for falling victim to a destructive oxidation process (rust) when exposed to open air and water. While exposed aluminum goes through its own oxidation process, it actually results in creating a harder, more impervious barrier that makes it even stronger. This can be seen if you look at aluminum ladders- new ones are slick and shiny, old ones have a more faded white appearance (but are just as strong).

Most aluminum folding door frames are powder coated from the factory with paint. By the time they’re installed in your home, they’ve already been sealed against outside elements, so you won’t even have to worry about aluminum oxidation in the first place. If you’re looking for overall durability against the elements- aluminum is probably your best option.

Although aluminum is one of the most abundant elements found in the earth’s crust, the process of refining it is lengthy. This means that it can be a bit more expensive when compared to synthetic vinyl materials or engineered wood.

One of the other drawbacks of aluminum that homebuilders commonly cite is that it’s not the most energy-efficient material. Because it’s a metal, it tends to retain heat. If you’re purchasing high-quality aluminum doors, then the manufacturer probably sealed and insulated the door to counteract this. However, if you’re purchasing one of these discount aluminum doors, then you could stand to lose some of your valuable cold or hot air in the winters and summers.

Before deciding on an aluminum folding door, always make sure that you research the manufacturer and assess the quality of aluminum that they’re making. While you do want a lightweight aluminum, you still want a sturdy, efficiency-optimized door.



For homeowners that are looking for a more luxurious style, then hardwood is the way to go. Not only is hardwood incredibly durable, but it’s also a great natural insulator which makes it a great choice for energy-efficiency. The most commonly used woods are:

  • Oak
  • Ash
  • Poplar
  • Walnut

Hardwoods are heavy, sturdy, and resistant to temperature changes. As long as the wood is sealed properly (they almost always come with a factory stain and seal), then you won’t have to worry about water leaking into your space either.

Soft Wood

Some brands utilize softer wood, such as pine, cypress, or fir. While these types of woods are lighter and more economical, they aren’t built to last as long as hardwood doors. If you’re already investing a significant amount into room renovation, tearing down walls, and a tracking system, then it’s usually worth the extra money to use a wood that’s going to last.

Engineered Wood

Engineered wood can be a nice compromise between great looks and affordability. Engineered wood typically consists of a hard plywood interior. This means that the interior is made up pieces of shredded wood mixed with a composite glue that holds them together. The exterior sides of engineered wood are hardwood veneers- thin pieces of real hardwood plating to give the door the appearance of being 100% hardwood.

Although engineered woods is mostly man-made and less expensive than hardwood, sometimes it can be even more stable and last longer than hardwood. While 100% pure hardwood is a nice luxury feature, engineered hardwood can often be an equally great option if you’re comparing looks and durability.

Aluminum Wood

If you like the idea of sturdy, lightweight, rust-proof aluminum doors, but you want the appearance of a wood door, then you can have both! Quite a few brands offer hybrid folding door designs like this. The supportive frame of the door will be made up of aluminum and the outer plating will consist of the same hardwood veneers used to create engineered wood doors.

This can be a great option if you live in a humid area where the climate could cause typical wood doors to expand and contract. The aluminum will ensure that the doorframe maintains its integrity, but you won’t have to sacrifice that beautiful wood finish you’re looking for.

Vinyl (UPVC)

If you’re looking for the most affordable option, then vinyl is going to be the way to go. The technical term is UPVC (unplasticized polyvinyl chloride). Depending on which company you’re looking at, you may see both terms used. Just keep in mind that they’re the same thing.

UPVC is an incredibly durable material. In fact, it’s the same material that they make plumbing-grade PVC pipes out of. If you’ve ever done any plumbing work, then you’ll know just how hard they are to break or damage. If you look at your average cookie-cutter home or apartment complex, the chances are that all of the windows and even some of the exterior door frames are made of UPVC.


Vinyl is also an incredibly energy-efficient material. If you’re looking at a folding door company’s “green” options, the door frame is likely made of this material. Last, but not least, vinyl is a very lightweight material, which means you’ll typically pay less in shipping costs, and installation may be quicker and easier.

The main reason why it’s more affordable is that it’s easier to create and more abundant- as is the case with many artificial compounds. Pretty much the only technical drawback of vinyl folding doors is that they aren’t as resistant to heavy winds, which means they wouldn’t be the best option if you’re looking for a hurricane-proof option.


Although it’s not as common as aluminum or vinyl, some manufacturers offer or even specialize in steel folding doors. The main advantage of steel is that it’s incredibly durable. If you need a solution that provides great security and is also able to withstand hurricane-force winds, then this metal can be a great option.

The main disadvantages of steel doors is that they can be incredibly heavy and sometimes quite expensive as well. However, if you’re looking for extra security, this material can give you some peace of mind. When coupled with storm-proof glass (or even bulletproof), then your “wall of windows” can be as impenetrable as the Presidential Limo.

Ease Of Ventilation

One of the main reasons why many homeowners opt for a folding door system is so that they can easily ventilate their home during the best seasons of the year. While both standard bi-fold doors and panoramic-style doors both give you the option to open up an entire wall of your home, the panoramic-style doors can provide easier options for ventilation.

This is because panoramic doors consist of individual panels. For instance, you could slide one panel to the side, leaving a 1-meter gap in your window system. You could then position the remaining panels to allow small gaps of air to get through each opening. Just like this:


In order to ventilate a bi-folding door system, you would have to slide both connected panels to the side, which would result in a larger opening. This could be undesirable if you’re worried about birds or leaf debris flying into your home.


After you’ve selected the material that you want for the door frame, the next most important part is the type of glass that you want. There are tons of different options for glass, and most folding door companies offer multiple options depending on what type of solution you’re looking for. Here’s a look at some of the most common options you’ll find when comparing brands and door styles.

Soundproof Glass

If you’ve ever been in a glass room, then you probably remember that glass can actually amplify a sound. Its hard surface makes it the perfect material for sounds to bounce off of, and many sounds can actually make it through a thin sheet of glass. If you live in a noisy area, have loud machinery, airplanes, or train tracks around your home, then you may want to consider using a soundproof glass solution.

This can be done in a number of ways.

One of the most common solutions is just to go with thicker glass. The thicker the glass is, the lower the chance of outside noise coming in. The only problem is that this can create a heavier folding door panel, which may need to be supported with a stronger tracking system.

Another common solution is to place a piece of transparent plastic material between two outer sheets of glass. Plastic has superior sound absorption properties, which makes it the perfect material for soundproofing your folding door system. Other systems utilize multiple thin windows panels stacked on top of each other.

Different companies each provide different sound-proofing solutions that are designed to work with the overall design of the door panel and tracking system.

Glazed Glass

Glass-glazing refers to the process of layering glass panels in a door or window system. Single-glazed windows are the most common and consist of a single glass panel separating the interior from the exterior. Double and triple-glazed windows refer to windows that consist of two or three separate glass panes layered on top of each other.

 The more panes there are in your folding door system, the less sound can get through, and the more energy-efficient they’ll be. Sometimes the glass panes are even coated with a metallic oxide to create “low emissivity.” This effectively creates a temperature barrier that keeps your home better insulated.

Laminated Glass

If you’re looking for glass that’s both secure and storm-proof, then you may want to opt for laminated glass windows. Essentially, this involves placing a thin invisible plastic film over the surface of the glass. In the event that strong winds, flying debris, or a burglar with a baseball bat decides to hit your windows, they’ll shatter, but will still be held together. This means that even if your glass is damaged, you’ll still have a protective barrier up to protect you from the storm or keep a burglar out.

Some folding door companies offer glass lamination as an additional additive to multi-pane glazed windows as well.


Frosted Glass

Frosting glass involves the process of sand-blasting or acid-etching the surface of a clear glass window. This creates a window that has a “frosted” or “foggy” look, and is an excellent solution if you’re looking for more privacy. Customers who are using a folding door for their bedroom or bathroom area will sometimes select this option as it can be easier than installing a curtain or blind system.

Window Tinting

If your folding door system is going to be installed on the side of your home that recieves a lot of sunlight throughout the day, then you may want to consider adding a tint on the outside-facing side of the glass. There are multiple options for tint that are each designed to provide more or less protection from light and UV rays.

Not only can tinting ensure that your home stays energy-efficient, but it can also give you some added privacy and keep people outside from looking in. If your folding door company doesn’t offer factory tints, then you can usually hire a third-party tinting company to handle the job after installation.

Door Handles

Whether you select a bi-fold door system or panoramic doors, one or two of your panels will be designated as “primary doors.” These doors will serve as your everyday single-action doors that you’ll walk in and out of your home with. The primary door will usually be the only panel that contains a door handle as well as the locking mechanism.

That being said, you’ll need to select a handle for your folding doors. The most commonly-used one is your typical L-shape handle. These are easy to grasp, require minimal force to unlatch the door, and also look nice with the wide aesthetic of glazed door panels. Should you desire a different type of handle, though, most folding door companies will be happy to meet your wishes. You may even be able to install a code-locked door handle for added security!

Door Threshold

One of the technical aspects that most people don’t consider is the type of door threshold that they want. The threshold is the lip at the bottom of the door where the door closes against. While it may seem like a small thing, the type of threshold you have can make a big difference if you’re looking at things like mobility or weatherproofing.


Weathered Threshold

Weathered thresholds are the most common. They include a small lip facing the exterior of your home. When your folding doors are closed, the lip provides a water-tight seal so that rainwater or flooding can’t get under your door and inside of your home.

The only disadvantage to weathered thresholds is that they can be a hindrance to elderly people or those using mobility devices and wheelchairs. The weathered lip means that you’ll have to take a larger step to cross the threshold; if you have a mobility device, you’ll have to gain some momentum to cross the threshold.

Non-Weathered Threshold

Non-weathered thresholds are flush with the ground. This means that they look a lot better. They’re also easier for anything with wheels to cross- whether that’s a stroller or a wheelchair. The main disadvantage is that they’re not as watertight as a weathered threshold. Most non-weathered threshold systems include a small drain system directly in front of the door to prevent water from crossing the threshold and entering your home. While this can protect you from a typical rain shower, it won’t do much in the event of a true flood.

H2 Locking Mechanism

H3 PAS-24 Accreditation


The size of your door is a very important consideration and will play a large role in determining the overall cost of your folding door system. The average folding doors used in homes are between 5 and 8-feet tall. However, depending on the design of your home, you may opt for an even taller door system.

Door panels themselves are around 1-meter wide, which is just over 3-feet. Keep in mind that the larger the door panels are, the heavier they’ll be to move. Even with today’s hi-tech tracking systems, a 10-foot tall door can require a bit of arm strength to move.

Energy Efficiency

Energy efficiency is one of the most important aspects to look at when comparing folding door models. In the “Glass” section, we covered a few of the glass options that you can choose from to make your folding doors more energy efficient. We also mentioned that selecting weathered thresholds can provide a better door seal and prevent drafts or leaks from getting under.

Many door companies have a special line of “energy-efficient folding doors,” which are designed with the latest thermal insulation technology, but some companies will allow their buyers to hand-pick all of the materials used to make their doors, so it helps to know your options.


Depending on where you live, local governments will have different mandates for the required U-value of your doors and windows. U-value is a measurement that describes the amount of heat transferred between two sides of the door or window. The higher the U-value, the more heat transfers from one side to the other; the lower the number, the less heat transfers.

Many states and countries have a minimum U-value of 1.8 or 2, but this number can vary from state to state or by country. Most folding door companies utilize materials that put the U-value between 1 and 1.3 so that they’re well above industry standards.

Polyamide Thermal Break

Remember earlier in the guide where we mentioned how some windows are soundproofed by the insertion of a thin film of plastic between the sheets of glass? Well, in order to make windows more energy-efficient and give them a lower U-value, many manufacturers do something similar.

A polyamide thermal break involves placing a thin strip of plastic polymer material between two panes of glass. This creates a thermal barrier that helps to lower the transfer of energy between two surfaces, keeping your interior climate-controlled and the exterior out.

Other Considerations

Now that we’ve got a lot of the technical specifications out of the way, here are some of the most commonly-asked questions about folding door systems that we’ve been asked.

What’s The Cost?

Let’s be honest- if you wanted a “cheap” option, then you would have just kept your existing square windows from the 1980s. On average, most high-quality folding door systems will run you from $700-$1,500 per linear foot. The price can vary depending on the type of materials you choose, the size of the panels, and any extra specifications that you choose.

Aside from purchasing the folding door system itself, you’ll also need to pay for any additional renovations that you may need. This could include knocking down a wall, rerouting plumbing and electrical wires in said wall, adding extra supports, and replacing/painting new drywall. After all of this, you’ll still need to pay a licensed contractor to install the doors. After paying for the folding doors, renovations, and installation, you could easily be looking at $7,000 to $10,000 minimum.

Do Folding Doors Pose A Safety/Burglary Risk?

Some customers have safety concerns when it comes to folding doors. While they are made of glass, they are just as “safe” as a glass front door to your home. If you’re looking to make them more secure, you can choose laminated glass or impact-resistant glass. In addition to this, you can add a modern laser security system that will trigger an alarm in the event that the glass is shattered or the door opens/closes when the system is armed.

Do I Need Planning Permission To Install Folding Doors?

If you’re replacing an existing doorway or entrance, such as a pre-existing sliding glass door with bi-fold or panoramic doors, then you likely will not need permission. However, suppose you’re widening an existing doorway, knocking down walls, and rerouting electrical/plumbing. In that case, you or your contractor may need to apply for a permit from your local city council.

In addition to your local city council, your neighborhood HOA may also want to review your plans for modifying your house. It’s always best to make sure that your paperwork is covered on both ends of the spectrum in order to save time lost and prevent any headaches.


Final Thoughts

We hope that this guide has helped you understand folding doors, how they work, and your options. Modern folding doors are durable, energy-efficient, and easy to install and operate. While they can be expensive, they’re no more costly than renovating your kitchen, bathroom, or any other space in your home.

If you’re looking for a stunning addition to your home that will bring in more light, allow better ventilation, and open your house to the outside world, then folding doors are one of the best investments that you can make. If nothing else, they’ll undoubtedly raise the value of your home and make it an eye-catching choice on the real estate market further down the line.