Large-scale glazing, especially in the living room, has become wildly fashionable in recent times. To what do they owe their popularity? They achieve a spectacular effect, decorate the interior and the volume of the building itself, and conveniently connect the home and garden areas. But what about the practical aspects? Are such windows airtight, safe, expensive? We answer the most frequently asked questions.

When choosing an HST system, do we expose ourselves to draughts?
The HST construction has become very popular in Poland. It is a solution taken from southern European markets, where we definitely observe a different climate. Consequently, the air-tightness parameter of terrace doors is slightly different from traditional window systems, but still qualifies for the highest, 4th class. This is all thanks to a well-thought-out pressure seal system. In the HST construction, we use a parallel, adjacent sealing system – which performs its functions perfectly.

It is worth remembering that in the case of joinery, a properly executed installation plays a huge role; a well-installed terrace door in the HST system should not cause noticeable ventilation in the house.

Do I need to choose aluminium windows for glass façades?
Façades, or ‘glass walls’, are designed to let as much light into the interior as possible. Often, large dimensions or non-standard dimensions also have an impact on the visual aspect. In practice, the dimension of the planned glass panel also determines the choice of material. In the case of HST constructions, the maximum dimension is 14 m2 , or 7 m2 if the investor envisages a single sheet of glass that will not open. On the other hand, in the case of entrance doors, regardless of the dimensions, aluminium systems are dedicated.

However, we always remind investors that when choosing aluminium windows for large glazings, they can successfully mix solutions and e.g. use PVC for windows with smaller surfaces.

In order to have a threshold-free passage in the case of the HST system, a special threshold must be purchased?
With the FEN 82 HST structure, at any stage the investor can retrofit the sliding window with a flat threshold with concealed rainwater drainage. Throughout the entire depth of the threshold’s installation – nearly 200 mm – the only visible structural element in the light of the passage is a low, 5 mm running rail.

As standard, HS thresholds have a sill height of approximately 30 mm after complete installation – a visible, natural slope for water drainage.

Are large windows expensive?
It is worth remembering that the size of a window affects its price, but it is not the only factor that matters:

Opening type – by far the most economical solution is to use a FIX window, which is a fixed, non-opening design. Among the opening systems – the cheaper will be the PSK tilt and slide system, and the most expensive is the sliding system – HST.
The material from which the window is made – PVC (more economical version), aluminium.
Choice of veneer – from one of two price groups.
Bicolour – i.e. window veneered or painted (in the case of aluminium windows) on the outside and inside.
Extras – i.e. choice of warm frame, warm window installation system etc.
If we were to compare an opaque wall with a glazed one, it is indeed the more expensive solution. However, it is worth remembering that there is a reason why there is a trend towards large-scale glazing, and being in an interior where natural light enters means better comfort and well-being for the occupants. In addition, convenient covers such as façade blinds allow you to freely control the amount of light.

If you want to optimise the price – we recommend non-opening windows of the FIX type, which are also perfect for investments with mechanical ventilation with heat recovery.

Are large windows difficult to clean?
Large glazing can indeed be cumbersome to clean. It is always worth thinking about the practicalities at the design stage of a house – an entire wall in the form of a glass façade will create an amazing effect, but at the same time may generate the need to hire external companies to help or to use a washer on a long telescope.

Lower windows can be successfully cleaned by yourself, and the operation is the same as for all other windows. So why does this question often arise? Let’s remember that if you have a terrace window and children at home, or pets – you inevitably have to clean such a window more often. In this case, builders often use two solutions that make cleaning easier:

The use of Bioclean self-cleaning glazing, which prevents water from settling when it rains, so the glass stays clean for longer. However, it still needs to be cleaned, but much less frequently.
Window cleaning robots – more and more products are appearing on the market that take the chore out of cleaning windows.

Large window – does it affect safety?
When choosing large-size glazing, we should not worry about safety aspects. Each window size has specially selected components, the selection of which is based on numerous safety tests. However, it is worth taking into account the fact that the size of the window may require the use of hardware with a higher load-bearing capacity or safety, toughened or laminated glass. Additionally, at the product selection stage, it is possible to opt for built-in reed switches, enabling connection to any alarm system.

Large windows – what to look out for and what can a builder forget?
In the case of large windows, as with all other windows, it is worth considering what the needs of the future occupants are, who will use the products, what our visual preferences are, what thermal parameters the products should have.

In the case of glass facades, it is additionally important to bear in mind the thermal comfort inside the room and the aspect of providing privacy. In both cases, façade blinds are ideal.