To efficiently move towards a more sustainable dwelling stock in Belgium, priorities need to be defined. Accordingly, it should be questioned if the new policy measure requiring the passive standard for newly built residential buildings from 2020 onwards is justified. This paper emphasises on the energy related aspects of the results of a PhD research. In the research residential buildings in the Belgian context were optimised from a life cycle environmental impact and cost perspective. The results proved that not for all dwelling types and layouts the passive standard is the optimal variant. A well-considered design, orientation and choice of dwelling type will be necessary to make the future requirement of the passive standard technically feasible and efficient.