Before we start talking about the cost of bifold doors, whether they are internal or external, we should find out exactly what people mean when they talk about this type of door, and we should look at some of the alternatives available on the market.
What are Bifold Doors?
Bifold doors, also known as accordion folding doors, are made from a collection of panels, usually made from aluminium, timber or uPVC (the same material from which double glazed plastic window frames are made), and are connected together by hinges so that they can open and close like an accordion bellows, The panels have a guide channel fitted to the frame at top and bottom so that the doors can smoothly run within them. When the doors are closed the panels sit edge to edge effectively blocking the opening and when the doors are opened the panels are neatly stacked face to face at one end of the opening.
Bifold doors used to be very expensive and confined only to the wealthier of homeowners but they are becoming more and more popular and so are becoming more in reach of the ordinary householder’s budget. They are a way to open up the inside of the house so there is a seamless join between the inside and outside. They are also useful as internal doors as they can effortlessly change the layout of a house and either have a large room for family gatherings and entertaining or smaller more practical rooms for personal pursuits.
Whichever one you choose, whether they are exterior bifold doors or interior ones, it is far better to have them installed when the house is being built because of the extra support needed for the wall above the wider opening that is usually chosen. That’s not to say that you cannot have bifold doors retrofitted, it just means that there will be longer lintels installed to take the place of load-bearing walls.
Bifold Door Sizes
Bifold door sizes vary depending on whether the doors are internal or external and also vary depending on the manufacturer. Having said that, there are standard sizes that most manufacturers adhere to.
Most of the time the standard height for interior bifold doors will be about 2078mm although the maximum can be up to 2500mm. The measurement that is the most variable, however, is the width and this will determine how many panels you end up with. Basic sets of internal bifold doors will most likely have 2 or 4 panels although most manufacturers also offer 3, 5 or 6 panel options. In order to get the correct width for your internal opening, whether it is for room dividers or wardrobe doors the width of the panels will vary. The width of most internal door panels vary between 700mm to 1000mm. If you want wider panels than these then you will need to look into having some custom made with the obvious substantial increase in cost. Similarly, if you need taller panels than those supplied as standard you will need to have some custom made.
Exterior bifold doors, on the other hand, are usually wider than internal bifolds. External standard bifold door sizes tend to be between 2090mm and 2100mm high (slightly taller than internal bifolds). It is the widths that vary significantly and these will depend on the aperture you have to work with. For a small opening, the width could be 1800mm using 2 panel bifolds or for a large one, it could be 4800mm with 6 panels.
Aluminium bifolds are often used for external applications and these are usually a lot larger than uPVC ones. Aluminium panels can easily be made up to 1000mm wide (although some styles are 1200mm wide) with the complete door being anything up to 6250mm
External Bifold Door Costs
As stated previously the price of the panels can vary depending on size and manufacturer. Similarly, the cost to install the panels will vary depending on where you live and many other factors depending on the site conditions, if radiators and electrics need to be moved or if any structural work is required.
The following prices give an indicative idea of how much selected exterior bifold doors will cost.
| Material | Dimensions | No. of Panels | Material Cost | Installation Cost |
| uPVC | 2700mm | 3 | £1600 to £2000 | £800 to £1000 |
| uPVC | 4700mm | 5 | £2800 to £3500 | £1000 to £1300 |
| Aluminium | 2700mm | 3 | £2300 to £2600 | £700 to £1000 |
| Aluminium | 4700mm | 5 | £4000 to £4300 | £900 to £1100 |
As you can see, aluminium doors prices are much more expensive than uPVC, so why decide to choose this material. Simple, because the material is stronger than uPVC it is possible to have the bifold doors slimmer meaning they take up less room when open. If we look at the aluminium bifold doors prices to install however we can see that they are fairly comparable with the uPVC models.
How Much Do Internal Bi-fold Doors Cost?
Many internal bifold doors are made from louvre doors with ventilation slats where the glass would normally be. It is possible to do this because they don’t have to be weatherproofed. These are usually used as wardrobe, pantry or closet doors. These are really out of our scope in this article, being more interested with internal bifold doors with glass infill within the panels. Internal bifold doors, because they are less prone to weather effects, don’t have to be draught proofed, and are less of a security problem, and so tend to be less structural and less expensive than the external bifold doors.
Although there are many factors that differentiate the internal from the exterior bifold doors, there will be little point in reducing quality on the glass. Glass in the home can be very dangerous especially if the family has young children. These little tykes insist on running around the house and where glass is exposed, such as with glass bifold doors, they run the risk of being seriously injured. Because of this, glass quality fitted into doors and lower windows have to pass a certain level and come under the jurisdiction of the UK Building Regulations. Any reputable manufacturer knows about the regulations and will usually give the purchaser a choice from the varying styles available. Having said that they are still expensive with some oak finished clear glass, 3 panel models retailing at about £820. The following table shows indicative prices for varying sized internal bifold doors.
| Aperture size | Door panel | No. of Panels | Cost |
| 1228mm x 2084mm | 381mm x 1981mm | 3 | £820 |
| 2380mm x 2084mm | 573mm x 1981mm | 4 | £1000 |
| 3138mm x 2084mm | 610mm x 1981mm | 5 | £1300 |
| 3750mm x 2084mm | 610mm x 1981mm | 6 | £1400 |
Which is the best bifold door?
In order to understand which are the best bifold doors, one has to take a careful look at the requirements you think you need and how the various manufacturers go about supplying these. We can look at each of the factors in turn and hopefully gain an idea of which is the best.
- Aluminium is by far the strongest material commonly used in bifold doors. This allows the designers to keep the framework to a minimum allowing more glass in each panel. They are also resistant to flexing and twisting and don’t easily expand or contract with temperature or humidity changes.
- Thermal efficiency. uPVC has the highest thermal efficiency(average U value of 1.7W/m2) compared with timber and aluminium. However, these can warp which will reduce thermal efficiency.
- Aluminium is by far the best for being maintenance free. The metal is usually powder coated and needs no painting. Aluminium will not corrode or rot, discolour or warp. They only need an annual wash with soapy water to keep them in good condition. The finish coat can be customized to withstand salt air on coasts and chlorine in a swimming pool environment. Compared to this, uPVC is also low maintenance but can be damaged by sunlight and can be scratched easily. Timber needs the most maintenance and needs repainting every few years, more frequently if the climate is extreme. Always look for bifold doors that are rated to British Standards.
- For modern finished aluminium is by far the more versatile. The powder coat finish can be colour matched to the purchaser’s requirements. Aluminium allows thinner and less material in the frames which allows for more glass.
- Although price will come into the choice of materials, it shouldn’t be the only factor. Aluminium is the most expensive out of the three common materials but considering that the material has far more advantages than uPVC and timber, it isn’t surprising that many people choose this option.
Alternative Doors
If for any reason you cannot have bifold doors fitted to separate your interior from the garden and patio, because of lack of space or for any planning constraints, there are a number of options you can choose from.
- French casement doors. These are a pair of normal external doors that sit in the same frame and open together. These are sometimes called double doors.
- Single external door. This is a straightforward single door hung from a standard door frame.
- Sliding doors. These are glass panels that slide in runner channels and slide past each other. Usually, they come as two panels with one panel fixed.
Although a comparison of these various doors is outside the scope of this article, it is worthwhile speaking a little about sliding doors because they have increased in popularity like bifold doors.
Sliding Doors
Like bifold doors, Interior sliding doors and external sliding doors have both seen an increase in popularity over the past few years. Although both types allow the rooms to be opened up, sliding doors do not allow as much as bifolds. They tend to be more popular when lack of space, either inside or outside, will prevent the bifolds from folding back when open.
Costs for other types of doors
As explained previously, patio doors can be bifold, sliding or casement french doors. The type you choose will depend on your preference as well as any planning constraints you might have on your property or in the area. Certain buildings with a cultural or historical background may be constrained to use just one type. Similarly, there is the choice of material. Aluminium patio doors are definitely superior to timber or uPVC models for the reasons stated earlier. The following table shows the indicative prices of each of the three types of patio door. In each case, the sizes are comparable.
| Type | Material | Average Cost |
| 3 panel bifold | uPVC | £1600 minimum |
| French doors | uPVC | £800 minimum |
| Sliding doors | uPVC | £1100 minimum |
Conclusion
Well, we briefly discussed the various types of patio doors available and went deeper into the bifold patio doors. We found out that each of the materials used in the manufacture had their own pros and cons but overall the aluminium framed bifold doors were generally superior to the others. They were, however, more expensive than the rest. Whichever one you finally decide to choose, we hope that you have many years use from them.
