How to replace windows? Everything you need to pay attention to
Unfortunately, in most older buildings, built a dozen or even several dozen years ago, the window joinery is not of the highest standard. What is the reason for that? First and foremost, due to the technological limitations of the time. Today, advanced window solutions are within our reach, but this requires thermo-modernisation. If you are determined to do so, here is what you need to look out for in the context of window replacement. How do we choose the best windows for our home?

Window glazing
The first element we need to think about is the glazing. Representing up to 85% of the surface area of the entire window, they cannot be ignored. Window panes perform a number of functions. Firstly, they determine the level of thermal insulation of the house. Therefore, it is essential to check the heat transfer coefficient Ug for a particular pane of glass. This is the amount of heat lost through 1 m2 of glass. Obviously, the lower such a coefficient is, the less energy will escape through our windows. Secondly, the better the glazing, the higher the level of noise protection. This is especially important from the perspective of those living in the city – or who have neighbours with specific musical tastes or a noisy dog. Thirdly, the glass lets light through and illuminates the interior. But not all will be equally good in this respect. Therefore, check the light transmission coefficient Lt for a particular window pane – the higher it is, the brighter it will be. This has a key impact on our daily wellbeing, especially in the months when light is scarce.

Fourthly, glazing determines safety. Of course, secure glazing must be accompanied by high-quality window joinery. Nowadays, customers are mainly offered glazing with increased burglary resistance. No window pane can guarantee 100% protection during a burglary, but it can significantly delay it. That is why at AIMWIN we have come up with an initiative which significantly increases the security of your home – the safeHOME package. It allows the installation of burglar alarm sensors already at the construction stage, The sensors are fully integrated with AIMWIN joinery elements, thanks to which the whole looks aesthetically pleasing.

Aluminium, PVC or timber windows?
Another consideration is the choice of their profile. Apart from typical aesthetic issues, such as colour or texture, we should primarily focus on the material used. Which window models can we find? Aluminium, PVC and wooden windows. The latter are rather being abandoned, mainly due to their high price and technical parameters, so let’s focus on PVC and aluminium windows. What is the main difference? The former are usually used in private homes. This is primarily due to the extremely good insulation parameters of PVC windows. Aluminium windows, on the other hand, are more commonly found in hotels or office buildings, as they allow large glazing areas to be created. However, windows covering almost the entire wall are also a visible trend in the case of private investments based on modern designs. If you are interested in this solution, please see our Aluminium joinery section.

Burglarproof window – Bet on safety
Does an anti-burglary window guarantee one hundred per cent protection against a thief? Unfortunately not, but they can considerably slow him down, and very often also discourage him, after a few/several minutes of fixing with the window. What determines whether a window is qualified as burglar-proof? We’ve already mentioned burglar-proof glazing, but it’s not just the glazing that makes a difference to the level of security. It is also the choice and positioning of the fittings and the way the windows are installed. Let’s check what burglary resistance class the selected fittings have. Security hardware is characterised by, for example, a higher number of anti-burglary strikers. However, our proposal for a safe window is the aforementioned safeHOME.

Is eco-windows worth it?

An energy-efficient window, but it is worth summarising a few points. Is we are betting on an energy-efficient house, eco windows are essential – choosing the right windows is even crucial. They will allow us to significantly reduce our heating bills because, firstly, they let much less heat outside and, secondly, they illuminate the interiors well. Whether a window is energy-efficient and can be used in a passive house is determined by the properties of the glazing, but also the profile itself and even the size and arrangement of the windows.

The greater the number of panes in a glazing package, the better the insulation of the glass. It is also worth paying attention to the solar energy transmittance coefficient. A high value indicates that more natural light will find its way inside the building.
The Uw heat transfer coefficient tells us how much heat escapes from inside the building through the windows. Energy-efficient windows guarantee a low Uw coefficient of no more than 0.9 W/(m2.K). Aimwin offers windows achieving even lower values – for some solutions it is even 0.75 [W/m2K].

Proper installation of windows is a guarantee that no thermal bridges will occur. It is best if it is carried out by the manufacturer himself, who knows his product best.
As far as profiles are concerned, the depth and width of profiles influence the degree of window insulation. A greater profile depth means that a larger glazing package can be used. On the other hand, a large profile width means a greater percentage of the total window construction, which has an impact on the Uw energy transmittance coefficient.
Southern exposure of windows means more natural light and better insulation. In passive houses, the installation of windows on the north wall is discouraged.

Choose a reliable window manufacturer
Finally, if you’re going to replace your windows, go for a reliable and reputable window manufacturer.  It’s best to opt not just for windows, but a whole set of joinery for the house from one manufacturer, so that a consistent effect can be achieved for the whole project.

How long does it take and how much does it cost to replace the windows?
The cost estimate for window replacement depends on a number of factors – their number, size, type (balcony, terrace, roof, etc.), the glazing selected, profiles, hardware, and the area of the investment. Replacing all the windows in a house is usually a considerable expense, but it is worth remembering that this is an investment for many years. An investment that can pay us back to some extent – for example by choosing energy-efficient windows. On the other hand, the time needed to replace windows depends mainly on the number of windows. Several windows can be replaced in just one day.

Replacing windows may seem like a complicated matter, but the most important thing is to have the support of a proven window manufacturer. They will advise, answer questions and above all, choose the best windows for us.