This paper proposes a critical analysis of the intervention, over time, in the housing estates built under the Improvement Plan for the city of Porto. This plan enabled the construction of a significant number of dwellings within a limited period of time, promoting a broad and impactful urban and social restructuring of the city in the mid-twentieth century. Several post-construction interventions over the last decades were important opportunities to improve the quality of life of the inhabitants and to enhance the energy performance of the buildings. However, these buildings are still subject to architectural and construction challenges in terms of ‘energy poverty’ and the adaptation of the domestic comfort parameters. Thus, this research analyses the intervention strategies used in these buildings and the constraints resulting from current legislation and funding conditions that significantly impact design decisions. The study points to significant changes in the implementation of measures to improve the state of buildings, becoming progressively more concerned with energy consumption and thermal comfort. The discussion also highlights the impact of current measures on the comfort of interior spaces, current problems, and alternative means of balancing energy and comfort. The relevance of this research lies in the joint analysis of the interventions and frequent efficiency and comfort problems as a motto to improve the implementation of future strategies in developing a more energetically balanced housing stock. The paper also aims to deconstruct the preconceptions often associated with interventions geared towards thermal comfort, especially in social housing.