What to look for when buying a patio door?

Choosing patio doors is a real challenge. After all, they are to serve for many years. So you need to conduct an analysis of what type we need and what solution the conditions at home allow us to install. Then you should get acquainted with the technical parameters of options available on the market. In this article, we suggest what to consider when making a purchasing decision.

Table of contents:

Hinged or sliding solutions?

There are two basic types of doors to choose from. The first is classic, open-ended solutions. The second one is modern sliding systems.

Sliding doors are more aesthetic, functional and also more convenient. One of the main advantages of sliding patio doors is that they do not require additional opening space. However, whether it is worth investing in their installation is determined by the width of the available opening in which they are to be installed. This is due to the fact that with a smaller width, the sliding door will be non-functional, because only one part is movable in it, and the width of the passage is less than half of the entire structure. Thus, for an opening width of 180 cm, for example, the passage clearance will be only 70-80 cm.

It follows from the above that with openings up to two meters wide, a classic opening balcony door with a movable post should be used. The movable post after opening both sashes means that no element will be left in the frame light. At the fixed post, the sash divider remains in the frame.

Swing doors

In the case of pull-apart solutions, depending on where we will install such doors, we can choose balcony or terrace doors.

A balcony door is essentially just a tall window mounted just above the floor. Thanks to the perimeter fittings mounted on all sides, they have functionality identical to windows, so they can be opened and tilted. They are operated with a standard window handle only from the side of the room. They are usually made of standard window profiles, but larger dimensions are made of wide profiles dedicated to patio doors. This type of door is available in single-leaf or double-leaf options with a movable mullion and opens practically only inwards.

The terrace doors are visually very similar to the balcony doors. They differ from them mainly by the lock. The patio door can only be opened and has no tilt function. They can be closed and opened both from inside and outside. Patio doors can be single or double-leaf and are most often equipped with a movable mullion. They can open inwards or outwards – depending on the needs. The profiles from which the patio door leaves are made are wider and more massive than the window profiles. Hinges are also elements of increased load capacity.

Sliding doors

When deciding on sliding solutions, we have a choice of two basic types: tilt and slide doors (i.e. PSK) and lift and slide doors (HST). Folding doors are definitely a less popular option, which, however, occasionally finds willing buyers.

Tilt and slide doors (PSK) use the same profile solutions as patio doors, but differ in the opening mechanism. Instead of hinges, special trolleys are used, which makes the active sash extend from the frame and can be moved parallel to the window to the other side, which is usually not opened. An additional function is the possibility of tilting them. Moreover, the leaf of the PSK sliding door can be made much wider than the swing door leaf, which is why such solutions are often chosen when the glazing is at least 2.5 meters wide.

Lift and slide doors (HST) are the largest and heaviest solutions. Their wing can be over 3 meters wide and weigh 400 kilograms! A support mechanism in the handle helps to lift this heavy door, making it easier to slide. When closing, the leaf falls down, sealing the entire structure. Most often, HST doors are constructed of a fixed part and a movable leaf that moves along a path parallel to the fixed part. But other opening patterns are also possible, for example with two middle sections sliding sideways where both outer elements are fixed glazing. There are also solutions in which both parts are movable and slide along parallel tracks.

Finally, one can also mention the folding door (FS) . This is the rarest type of opening. Most often, one of the wings is a classic tilt wing, while the other wings can be folded in the shape of a harmonica. Folding leaves run on two rails, one at the top and one at the bottom of the frame. It is possible to make a multi-leaf structure, which allows for glazing even a few meters long exit to the terrace. After opening such doors, the passage clearance covers almost the entire width of the frame.

Large glazings in the house

Workmanship and functionality

Once we have assessed what patio doors we can install, and we have chosen the appropriate system, aspects related to the quality of their performance should be taken into account. They are influenced by many factors: the material from which the door was made, the quality and class of components used, as well as performance parameters.

PVC, wood or aluminium?

The most popular on the market are products made of PVC. They are also the most affordable options. However, they have their limitations.

Due to the flexibility of the profiles, it is not possible to make really large glazing. However, this does not mean that PVC constructions have to be small. In their case, the wing can weigh up to 300 kilograms!

PVC is also less resistant to weather conditions. Years of exposure to strong winds, strong sun and extreme temperatures can lead to wear, especially aesthetic.

Wooden solutions are much more expensive than their PVC counterparts. However, the design possibilities and limitations are similar. However, they are dominated by the aesthetics of workmanship and the traditional elegance of wood.

The largest glazing, even several meters long, can be constructed thanks to aluminum systems. They are also the most durable and resistant to extreme weather conditions. And they do not require maintenance. Unfortunately, the price must follow the quality. These are quite expensive solutions, but if someone wants a first-class door that will retain its functional and visual parameters for many decades, then it is worth considering investing in aluminum.

The most demanding customers may be interested in wood and aluminum solutions. While maintaining all the advantages of aluminum joinery, we also get a product that is visually characterized by the class of wooden joinery. It is therefore a combination of the best features of both materials. By investing in wooden and aluminum terrace doors, we can be sure that we receive a product that is both technologically and visually perfect.

Performance parameters

The two most important parameters that we should pay attention to when choosing patio doors are their watertightness and wind resistance.

The water-tightness class of the windows informs customers about the tightness of the terrace door structure. Structures with a threshold made of a frame profile, i.e. with the same frame around, achieve the highest class of water resistance. Such windows obtain the E1050 class, which means that they remain airtight in the wind that blows at a speed of nearly 150 km / h! Structures with a low threshold, as well as lift and slide doors (HST), despite the use of a complex sealing system, achieve slightly lower classes of water resistance.

The wind load resistance parameter tells us how much our door can withstand. Wind load resistance is described by two symbols: a letter and a number. Due to the deflection of the frame, three classes are distinguished: A, B and C, while in terms of pressure, there are six classes: 1, 2, 3, 4, 5 and Exxxx (where xxxx is the value of the test pressure). Class C structures boast the best resistance to wind load. The maximum deflection of the structure is no more than 1/300 of the length, i.e. twice less than in class A windows.

Low threshold

Seen from the comfort perspective, the threshold height is a key aspect of patio doors. The use of a low threshold reduces the risk of tripping, and can also be extremely desirable in homes with small children, the elderly or people with mobility impairments.

Not in all the solutions discussed above, the low threshold is achievable. In balcony doors, its implementation is optional, although not very common. Patio doors usually have a low threshold as standard.

In the case of sliding structures, a low threshold is impossible to implement in PSK or folding doors. The reason is the need for a lower rail. In HST solutions, the low threshold is most often offered as standard.

Exit to the terrace.


Large glazing is also a characteristic feature of modern construction. Therefore, it is worth buying a product that will blend in perfectly with the body of the entire building, but at the same time characterized by very good parameters and quality of workmanship. If we choose patio doors from a reputable manufacturer, such as MS more than WINDOWS , we can count on high comfort of use and good thermal and acoustic insulation.

When making a selection, we can also equip the door with additional functions, such as automation, allowing to open the door remotely (available in HST solutions), or optional security elements, for example, safe tempered glass, door handles with a key, anti-burglary fittings or reed switches. There are many options, but each of them is worth considering and analyzing whether it will be useful at home, even if not now, maybe in a dozen or several dozen years.

Patio doors in the MS offer more than WINDOWS

See also…

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