Lammin windows and doors are thoroughly tested by VTT – they meet all the class 1 norms when it comes to air and water proofness and wind pressure.
Opening a window once a day adds up to almost 20000 openings in 50 years. In addition to the ability to keep the cold out and the warmth in, a good window is also strong enough for reliable daily use.
The better the heat insulation of the window, the lower the total expenses of living. Even if a quality window is a bit more expensive to purchase, the difference will soon be more than offset in the form of lower energy bills. Good wondows are also an efficient investment against climate change.