This work examines strategies for contemporary renovation of 19th century housing, focusing on three cities with significant ensembles dating from this time: Lisbon and Oporto, in Portugal, and Geneva, in Switzerland. Taking into account the unique urban identity of these areas, the main objective is to examine renovation strategies that make use of original layout and building features to address changes in domestic life and present-day comfort demands, in order to inform future interventions. The study is first directed at typological analyses of housing plans in specific areas, and relies on secondary sources, archive research as primary sources and statistical analyses. The main research issue concerns contemporary renovation strategies, which were examined through fieldwork on recent house renovations, analysis of architecture projects and semi-directive interviews with architects and residents. The analysis was focused, on the one hand, on the changes regarding use of space and distribution and, on the other hand, on how specific comfort demands were addressed: the thermal performance of roofs and walls, the thermal and acoustic performance of windows and the acoustic performance of timber floors. Moreover, the work is supported by a background analysis of the legal framework for the renovation of historical residential buildings, focusing on the topics of heritage protection, measures to promote renovation and housing, as well as the requirements for thermal and sound insulation.