Thermo-FRAME is a main element of STROPEX EMO frame system. The research carried out by Institute of Buliding Technology’s has confirmed Thermo-FRAME’s declared performance properties regarding admission to use in the energy-efficient and passive construction. The whole window’s statics has been considerably improveed by the increased window frame’s stiffness created by its mechanical connection to the Thermo-FRAME. Thermo-FRAME is made of two magnesium oxide wallboards filled with closed-cells rigid polyurethane foam.