This standard identifies thermals comforts, indoor air quality, lighting comfort and acoustic comfort as four critical elements of IEQ. Each of these elements have been covered by defining their threshold levels of IEQ parameters. Three levels for defining threshold values have been created; Class A (Aspirational), Class B (Acceptable) and Class C (Marginally Acceptable). The defined threshold levels become more stringent for class B and class A. Some parameters have been omitted in Class B and Class C as the standard is applicable to variety of buildings ranging from unconditioned residences to large air conditioned commercial complexes. Class A is comparable with internationally prevalent standards.