While carbon dioxide monitoring can be a relatively effective indicator of space ventilation performance in commercial buildings, it is not as appropriate for residential buildings. IAQ in the residential setting may be affected by numerous factors, including off-gassing sources (e.g., furniture, building materials) and emissions from combustion equipment (e.g. furnaces, gas ranges, fireplaces). Since residential units have relatively low occupant densities (compared to most commercial facilities), CO2 is not a reliable predictor of IAQ for this building type. This project has instituted the following measures to track IAQ in the apartment units and in public spaces: 1) Continuous CO2 monitoring in specialized public areas (e.g., Health Club) 2) Carbon monoxide alarms for spaces near combustion equipment 3) IAQ testing of all apartments to develop an air quality profile immediately prior to occupancy (to be performed at least once a year, or when new tenants move in, for a minimum of 5 years). The air quality profile will be conducted for each apartment by either a certified industrial hygienist or a licensed engineer, and meet the following criteria: A)