For the residential home builder

Are you building the house of your dreams?

By choosing Klas1, you receive high-quality windows tailored to the building's architecture—exactly according to your needs. Our windows are manufactured in Kuusamo, and our window solutions are always implemented according to your wishes.

The highest quality timber on the market is our absolute advantage

Pine grown in the harsh conditions of the North is particularly dense-grained and thus lasts throughout the entire life cycle of the building. Knot-free, Finnish pine free of resin pockets is selected as the raw material for our windows and doors. In addition to pine, we also manufacture windows from non-finger-jointed white oak.

Explore our windows and contact us!