Standards for choosing the right window
Windows represent one of the most important architectural elements of a building. Energy-saving, comfort and well-being of the interior depend on their characteristics. Finding the right window is a difficult and demanding task, both because generally the purchase of windows represents a choice of great value that must be done pondering in an appropriate way several aspects, both because of the many types that exist on the market, and without a right knowledge of the subject, they risk complicating the enterprise!
Let’s see, therefore, what are the standards to take into account to choose a good window:
1. TRANSMITTANCE AND WEATHER RESISTANCE
Each of us has surely happened, approaching a window, to feel a shiver of cold due to a decrease in the temperature of the air closest to the window or from some draught. During the winter season, due to these phenomena, 23% of the energy normally used to heat a house is dispersed from the windows. This dispersion value, also called “transmittance”, can be reduced depending on the material with which the window is made and the type of glass used. The lower the transmittance value, the greater the insulation, and therefore also the comfort, within the house. It is also important to contextualize the area of installation of fixtures and meet the requirements for thermal insulation established by law that vary from region to region, since in Italy each location has its climatic characteristics: It is clear that those who live in Aosta will have to take into account a much lower transmittance value than those who live in Catania. In general, it is good practice to stay below a transmittance value (Uw) of 2 W/mqk. Consequently, I would say that the first aspect to be taken into account in the choice of the window is its ability to insulate indoor environments or its thermal performance, the maximum yield of which will be only and exclusively if the installation is carried out in accordance with the law since the connection knot of the windows to the wall is in 70% of the cases the most dispersing element of the whole window system. By thermal performance I mean not only the transmittance value but also the weather resistance (rain, wind, snow and even excessive sunlight) for which there are several specific reference standards (Air-tight insulation according to UNI-EN 12207; Water leak seal according to UNI-EN 12208; Resistance to wind stress according to UNI-EN 12210)
2. SAFETY AND SOUND INSULATION
Doors and windows are the weak point of the structure, as well as from the point of view of the thermal insulation just seen, also for the safety issue. They represent the main access point for criminals who want to break into the house illegally. For this reason the safety of a window is essential. Beyond its basic structure, windows can be equipped with anti-burglary components, which help to increase their security against the phenomenon of burglary in the apartment.
There are different levels of security of fixtures determined by the use of anti-foundation glass and the type of closing mechanism chosen, passing from a standard level of protection, to a first, a second and so on.
Sound insulation is also a very important parameter to keep in mind especially for those who live in very noisy environments. Noise from the outside, in fact, represents a real problem that can undermine the comfort of the interior. A good window must therefore guarantee a high degree of sound insulation that depends on the type of glass installed (better if with single or double chamber), the number of gaskets mounted and the correct installation of the whole system. Also from the acoustic point of view, the fixtures can have a certification that determines the good insulation performance.
3. DURABILITY AND MAINTENANCE
A quality window is an investment that should last a lifetime! The conditional is obligatory because it depends on the window choice. It is important to choose windows made of materials that guarantee a good mechanical hold and that last over time, avoiding to carry out continuous maintenance work. It is therefore necessary to assess first of all the stability and robustness of the mechanical structure and whether it can support the weight of the glass pane without difficulty. It is good that the external surfaces are made of weatherproof materials, that a good opening and closing hardware with special alloys is used, whether the seals used are made of EPDM or PVC with great memory and high elastic power to resist cold and hot.
Last but not least, it is the aesthetic parameter. Considering the window also a piece of furniture, it is essential to harmonise it with the outdoor facades and the interiors in which it fits; here it becomes important to choose the material also for the aesthetic purpose. The colour, the finish, the lines, the dimensions and above all the details, for example the glass stopper or the hardware, make the difference and it is good that they are made choices in the respect of the style of the interior furnishing.