During the 17^th-18^th century colonial period on the Indian subcontinent, British colonial architecture flourished – including in the Bengal Delta. Although colonial architecture was inherently different from the traditional architecture of this tropical region, the monsoon climate and deltaic landscape forced colonial style buildings to incorporate a number of tropical architectural features to ensure climatic comfort. In the contemporary period, due to pressure from population density, many colonial buildings have been demolished and replaced with multi-story buildings. However, the tropical forces of this deltaic region need to be evaluated in order to re-create climate responsive architecture. This study aims to identify tropical architectural features inherent within colonial buildings of Khulna, Bangladesh, a city which formed a junction in the deltaic region during the colonial period. Four colonial buildings have been selected as case studies: two residential buildings, one mixed-use building, and a school. Tropical features were analysed from photographic data, and reproductions of plans and sections of the selected buildings, in order to reveal the significant tropical architectural features of these colonial period buildings. The case studies reveal structural and design elements that aided ventilation and air flow, and controlled solar radiation, humidity and driving rain. The findings aim to encourage practicing architects to rethink climate responsiveness in contemporary buildings in Bangladesh, by revealing how, a century ago, colonial buildings were influenced by the tropical deltaic climate, which impacted foreign architectural ideology and practice.