Building Bio Climatic Design Charts (BBCC) are essential for understanding the thermal conditions prevalent inside occupant spaces and aid in assessing the potential of passive and low-energy cooling strategies like evaporative cooling. An intensive field study carried out in 10 selected office buildings using direct and two stage indirect/direct evaporative cooling systems during the summer season in composite climate of Jaipur city. The respondent perception and preference were collected using transverse survey from 1554 samples spread over a total period of two years, covering, wide age groups and clothing types. This dataset was used to test the accuracy of ASHRAE 55's thermal comfort zones for the assessment of indoor thermal comfort in surveyed buildings. Study revealed that the subjects in the evaporatively cooled buildings of this region were comfortable at different temperature and humidity levels than those defined in ASHRAE 55 and ISO 7730 standards. This is attributed to the difference in comfort expectations and preferences, as well as the region-specific adaptation of people living in tropical climates. Redefined thermal comfort zones and design polygons for capturing the full potential of evaporative cooling were outlined corresponding to 80% acceptability criteria, based on field measurements and subject's responses for the indoor airspeed ranges (0-0.5 m/s, 0.5-1 m/s and 1-1.5 m/s). (C) 2018 Elsevier B.V. All rights reserved.