HVAC (heating, ventilation, and air-conditioning) and lighting are the most important parts of building design in the present-day energy crisis scene. The buzzwords in the building industry are eco-friendly, energy efficiency, and green concepts. The Central Building Research Institute (CBRI), Roorkee, has been vested with the responsibility of generating, cultivating, and promoting building science and technology in the service of the country. CBRI's focus is on green and energy-efficient buildings.

One has to understand that for a comfortable living it is not required to have a so-called modern house with luxuries such as air-conditioning. In fact the best design is one which is close to nature with natural air movement and light.

The design of a house/building for clean air movement and natural light is the need and engineers/architects should provide a comfortable indoor climate. If we observe our old and historic buildings it is well proved that our builders and architects knew that creating good ventilation was critical and provided cross-ventilation, proper ceiling heights and right orientation for the building, depending on the location and climate.

Every architect, building design engineer and student should visit our historic buildings and study the efficiency and energy performances of natural ventilation systems and understand the air flow patterns, air temperature and air velocity distribution.

Jaisalmer is one such city where the natural cooling systems are adopted for a comfortable living. Some of the natural cooling systems used there include: dense clustering of buildings, sun control through orientation and structural projections.