The purpose of this document is to describe a methodology for carrying out an Indoor Environmental Quality Control Plan. The field of application of this document are the indoor environments of all types of enclosures, facilities and buildings, except those that are intended "exclusively" to the activity developed in industrial and / or agricultural processes. This document is designed to ensure the well-being and health of the users of facilities, and does not interfere with compliance with regulatory requirements for the prevention of occupational hazards. This document is also applicable to common areas of hospitals (hospitalization, consultation rooms, outpatient areas, etc.) but not to controlled environment rooms (operating rooms, intensive care units, isolation rooms, etc.) which require more demanding air quality levels. Indoor environmental quality control in controlled environment rooms in hospitals and healthcare centres falls within the scope of application of the UNE 171340 standard. Indoor environmental quality control in hotel establishments falls within the scope of application of the UNE 171350 Standard.