“One experiment is better than a thousand expert assumptions” formed the point of departure for a cross-European demonstration programme of six Active Houses. Here, we look into post-occupancy evaluations. The paper presents the main common denominators among the houses and identifies learnings by analysing quotes from the families, and via methodology, developed as a result of social monitoring. The scientific reports and conclusions form a platform for discussion, definition and suggestion of common denominators. It concludes with recommended learnings which can be transferred to the wider housing stock, new as well as existing.