While choosing the door and window system, you must decide after performing a research on their surface maintenance, the resistance of the ingredients and their compliance with the building, whether it requires additional expenses after construction. The value of ALKOSAN windows is not calculated per part; the value they will provide to the building on which they will be installed and the life quality they provide are taken into consideration. In order to understand whether a system is economic for the building, in which it will be applied, ALKOSAN recommends you to review the following items: