Lumar IG is a company that is the leading Slovenian manufacturer of prefabricated buildings. In additon to guaranteeing innovative and environmentally friendly solutions, it can be found in many countries such as Slovenia, Austria, Itaaly, Switzerland and Germany. Till today company has built more than 2.450 prefabricated buildings, among which we can find more than 410 passive houses and three passive nursery schools. This fact implies that the company Lumar ranks first among the Slovenian manufacturers in terms of its constructed passive buildings.