The prefabricated houses can be divided into timber frame construction system and cross-laminated timber system. Timber frame construction includes structures in which the supporting part consists of a wooden frame, between which insulation is obtained, the exterior covering with panels (OSB or Fermacell)  gives the construction static stability. Later comes a classic or wooden facade and an interior covering as desired. The cross-laminated timber system includes constructions of cross-glued wooden elements. Houses that are built in timber frame construction fall under the low-energy or passive objects. All materials have passed the appropriate mechanical and physical tests and are environmentally friendly.