A code is a set of guidelines that offer a broad, subjective set of recommendations and means to achieve a certain end. The end in this case is a green building, or a structure that has a minimal negative impact on the environment and consumes minimal resources (water, energy, power) during its construction, operation and demolition stages.

There are certain rating systems based on existing national and international "building codes" like regular codes as the Energy Conservation Building Code (ECBC) and the National Building Code. One such system is the Leadership in Energy and Environmental Design (LEED) rating system. This system is developed by the United States Green Building Code (USGBC) and now adapted by Indian Green Building Council (IGBC). In India, TERI has developed its independent rating system called the Green Rating for Integrated Habitat Assessment (GRIHA) rating system. GRIHA is now endorsed by the Ministry of New and Renewable Energy, Government of India.

All such systems help compare the green quotient of buildings with nationally/ internationally acceptable standards. Usually there are ratings scales to determine whether you deserve a 5 star rating for your efforts to preserve the environment, or lesser such ratings.

The ECBC, as prepared by the BEE under the Ministry of Power, helps make an air-conditioned building energy efficient. However, this doesn't help categorise a building as green as there are many more issues other than power conservation which need to be addressed. Issues such as water and waste management, renewable energy applications, low embodied energy materials use also need to be considered before calling any building "green".