The Historical Centre of Old Havana in Cuba is currently undergoing a comprehensive preservation and urban recovering program. Housing units are built in existing vacant plots of the old city. The design of the new buildings should be integrated in the compact urban structure that has developed throughout the past centuries. This compact morphology however obstructs the breezes that are an essential component to achieve thermal comfort by passive means in warm and humid climates. New courtyard buildings should be designed in such a way that natural ventilation and thermal comfort are enhanced. Research on natural ventilation and thermal comfort in compact urban environments however is scarce. This paper first presents an historical overview of the typological evolution of the residential architecture in this part of the city and its relation to natural ventilation and thermal comfort. Next, it provides a partial study of the morphological characteristics of the Historical Centre. From this study, appropriate locations have been selected for field measurements and a limited comfort survey, from which a tentative summer comfort zone for residential buildings in Old Havana is suggested. Finally, based on the historical overview, the measurements and the survey, some preliminary design recommendations for residential buildings in Old Havana are provided.