Bjelovar, CROATIA - Croatian manufacturer of PVC windows and windows for passive houses since 2006, developed a special type of window. The aim was to obtain confirmation of the European Patent Office that their windows in all five points of the requested innovation acceptable and to serve energy efficiency. Now the goal is achieved. Technical solutions company "Troha Dil" from Bjelovar open the door to wider European markets, especially the northern regions where the demand for energy-efficient solutions on the rise. Based on the test result window was excellent, the windows are characteristically so far unique in test laboratories Passivhaus Institute in Germany. Continue to develop other products, entrance doors, sliding doors, balcony windows and other building elements for passive houses that have the same characteristics as the tested windows.