Warm installation, also known as airtight or layered installation, is currently the most advanced window installation method. It is gradually replacing traditional installation methods based solely on PUR foam. Over time, such sealing may lead to freezing, causing the window to lose its thermal performance in this area. The use of warm installation prevents heat loss in the window sill zone, significantly improving the overall energy balance of the building. It eliminates the effects of thermal bridges and drafts, while also reducing noise transmission. An additional advantage of this system is the much easier installation of the entire window joinery, as warm window sills do not require additional sub-sill profiles. Their profiles ensure proper leveling and high load resistance, both for interior and exterior window sills.