Energy and architecture form a natural marriage if indoor comfort and respect for environment are secured [1]. Although energy conservation is an important issue in present days but human thermal comfort is the primary concern in case of buildings. But energy conservation becomes a necessity rather than an option in both commercial and residential buildings without compromising the human thermal comfort. The use of day lighting and solar energy for heating and cooling as well as enhanced natural ventilation not only reduce the commercial energy demand but also minimize the negative impact on environment too.

The level of thermal comfort greatly affects the human’s physical as well as psychological health. In building design the weather condition or the climatic parameters, i.e. air temperature, relative humidity, solar radiation, rainfall (precipitation), wind speed and direction, etc. plays an important role. This fact is well supported by the studies on vernacular architecture as well as modern architecture throughout the world. For specified and systematic approach, classification of climates is done based on human perception. It is not a natural environmental occurrence rather it is an outcome of human attitude based on its need and use. We have carried out the detailed study on traditional architecture (Vernacular architecture) across the regions covering 42 residential houses. The houses covered under the study are constructed about 70–100 years back. Almost all the houses showed advanced passive features in construction, material use, orientation, window arrangement for ventilation, use of day lighting and construction techniques, etc. [2]. The residents of these buildings has general perception that these houses provides better thermal comfort and match the traditional requirements in comparison to modern buildings made up of modern materials.

India is kept under the tropical rainy climate (group A according to Koppen classification) and in sub group: tropical savanna climate (Aw) and tropical monsoon climate (Am). No doubt that this classification has its own importance but the information generated is quite general and qualitative in nature. This information can seldom be used for any engineering application in designing energy efficient buildings. For engineering application and designing energy responsive buildings we need to have very specific information. Hence, the primary aim of the present work is to identify the different bio-climatic zones in north-east India and to generate some specific information regarding temperature and humidity variation throughout the year which would provide architects and engineers an overall view of an appropriate climate responsive building design strategy that are conductive to make use of the natural environment and resources during the initial conceptual design stage itself.