The project aims to develop and test an innovative methodological approach to impact assessment directed to the next generation of public policies financed with European Community funds (2021-2027). This methodological approach is anchored in the triangulation of three basic methods: Policy–Scientific Approach, Qualitative Comparative Analysis and Contingent Valuation Method. The implementation and testing of the methodological proposal will focus on Investment Priority 08 of Portugal 2020 and its social housing support operations (developed under the regional operational programmes). This option seeks to build an impact methodology framed in the logic of “theory-based evaluation” and in the “realist evaluation” type that maximizes the potential of combining two essential theories for the current Public Policy Science, programming theory and causal theory, also taking as a milestone the determination of two basic pillars of public governance: the logic of results-oriented public policies and the principle of evidence-based policies. It is considered that the main added value of this proposal is not so much in the overall calculation of the effects of the interventions, but rather in the possibility of knowing in detail the causal relationships that result from them, attributing to it an effective economic value, no longer only in the perspective of the achievements, but above all from the perspective of the real impact.