From among all building elements, thermal insulation of external walls and flat roofs has the greatest impact on their energy efficiency.. These partitions are designed to protect the interior and occupants of buildings against the effects of weather conditions and excessive heat losses. Knowing, that leaks through the outer walls 40% all heat losses in single-family houses and approx. 25% in multi-family houses, and through flat roofs, respectively 18% i 6%, it is worth betting on solutions, which will effectively reduce these losses. Therefore, it is recommended to improve the thermal parameters of these partitions by using an insulation system. In the Passive House, the ECOROCK MAX system was used to insulate the external walls and the two-layer insulation of the foundation slab with Rockwool slabs.. They give the users maximum benefits.