There are serious reasons why we need to change the windows. I don't think there is anyone who changes the windows in their house or apartment just because of fashion or because they are bored with them. There is usually a very serious reason for doing so: thermal and sound insulation or irreparable damage to old windows. If we have to change them, we should at least be as well informed as possible and choose the best option for us.
Types of windows
There are four options: PVC, wood, aluminium and aluminium-wood combination. The strongest are aluminium and the weakest are PVC. Both PVC and aluminium can have foils applied to imitate wood.
I won't go into details about PVC and aluminium windows, because I'm not a specialist in such materials and I don't want to get it wrong. As far as wood is concerned, I can give you more information.
Wooden double glazed windows
Wooden windows can be made of various woods - resinous, oak, mahogany. The wood used can be solid or laminated. Single-piece solid wood windows are becoming less and less popular because of the instability of the wood. Laminated wood windows are much more stable, as there is very little variation in the wood's moisture content.
The problem with windows is the length of the elements. Dimensional variation can cause these elements to bend or twist. Laminated wood eliminates defects in solid wood, and lamination produces a strong and more stable wood derivative. Lamination also helps with thermal and sound insulation, as layers of wood with long but different grain layings make it harder for the wood to pass through.
The term double glazing refers to the glass of the window, not to the time of material used for the frame construction or the construction solution. Thermally insulated glazing is that sandwich of 2 or 3 layers of glass, with airless spaces between them or filled with gas preventing penetration, so that sound and heat insulation is ensured. Thermopane windows are only those that have such glass embedded in the frame.
The window must be constructed in such a way that the water does not puddle. The water level should be inclined at an angle. The condition for the window to last as long as possible is precisely this construction solution that removes water.
Finishing windows to make them last as long as possible
Special materials resistant to weather conditions and UV radiation are used to finish the window frames. The more solar radiation passes through the finish, the less resistant it will be over time. From this, the most resistant frames are the painted ones, where the wood fibre is completely covered, and the least resistant are those with a transparent finish. In the case of transparent finish, the least resistant are fully transparent glossy windows, and the most resistant are matt, semi-transparent ones.
The durability of finishing materials for wooden windows ranges from 3-4 years to 10 years, sometimes even 12-15 years. That doesn't mean that after 10 years you have to change them. This is the time after which the first cracks are likely to appear. In order to prolong the life of windows, it is best to have them serviced every 2 years. This means washing them and applying a maintenance oil (available in almost all shops) with a cloth or spray. Weathering will eat from this layer and the finish will be protected.
The durability of the finish depends very much on weather conditions. So, in the same house, windows on the side that is more exposed to rain and wind will last less than those in the more sheltered area. This is why it is very difficult to obtain a guarantee from varnish and paint manufacturers. And if you do get one, it's a real book, with instructions on window construction solutions and finishing technology.
If the windows of the old houses cannot be recovered, they can be replaced with double-glazed windows with wooden frames. There are companies that reproduce the original windows exactly, even if there are arches, double glazing or other construction details. So there is no excuse for old buildings to be mutilated.
I hope these few guidelines will help you when you want or need to change windows. At least, don't start from scratch in this action.
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There were some pretty serious errors in the article but the most glaring ones are in the paragraph below:
"As we know, solid wood has dimensional variations depending on atmospheric conditions (temperature and humidity) and, at large sizes, it can bend. Laminated timber has no such problems. It is made from layers of timber arranged perpendicular to each other and glued together. The result is a wood derivative that is very strong and stable over time."
Wood varies in size only due to humidity. Temperature does not affect it if the humidity remains constant. Variation in size becomes a problem with joints that have not been made with this in mind. Bending occurs when the joinery has not been designed correctly, when there are large variations between the humidity inside the house and outside and when the wood used has not been selected, seasoned, cut or finished properly for the joinery.
Laminated wood profiles do not completely solve the above problems but they do help dimensional stability. In addition, as you can see from the pictures in the article, unlike plywood, laminated profiles for joinery have all layers of wood with the grain in the same direction. It is not correct to say that "it is made of layers of timber arranged perpendicular to each other and glued together". .
Thank you for the clarification. Regarding the dimensional variation of the wood I was referring to the atmospheric conditions saying "temperature and humidity". You yourself say that temperature does not affect if the humidity remains constant. So, together, temperature and humidity can cause dimensional variation of wood.
Regarding the laminated wood joinery profiles, you are right and I will make the necessary modification.