The experts who have assessed the prospects for growth of the construction market, which until 2008 was governed by a strong upward, deem that today the analyzed field is more related to the rehabilitation works. The latest statistical measurements performed by specialized institutions revealed that the sector has a market share of about 70%. The main consequence is that the most material suppliers and contractors must rethink the strategies to address business, at least on short and medium term. The same thing also happens in the passive construction field, in which beneficiaries choose to minimize energy consumption while maintaining or even improving the comfort level. Shortly ago, researchers from the Passive House Institute from Darmstadt launched a certification module (EnerPHit) dedicated exclusively to the rehabilitation projects. Even from an early stage, some clear differences between this approach and the one concerning the new constructions could be identified. The most important difference regards the number of thermal bridges. Another challenge for the teams which conducted the experiment concerned the precise determination of heat transfer coefficients corresponding to those regions. A solution to both problems was obtained by developing a new insulation system certification model, dedicated exclusively to such applications. In short, the materials used must meet the EnerPHit thermal resistance requirements, and then there should be a close cooperation between entrepreneurs and experts of PHI, to address the specific problems of each project. Although the standard for passive houses has become a classic tool in the construction of new buildings, yet it cannot be applied in an optimal way to the rehabilitation projects. In these circumstances, the experts have reviewed and simplified the basic criteria used in the evaluation system. Also, the certification system was extended, by including insulation solutions which apply from the inside. In this case, the system used is EnerPHit+i, in which the required amount of energy is higher than the projects with exterior mounted insulation systems. For further information and a detailed analysis of the current TOP-Agenda Constructiilor issue click here!