The use of tracer elements to measure the air infiltration rates within residential and commercial buildings. A number of tracers and capillary absorption tubes are placed within the facility. Natural air infiltration forces the migration of tracers to the capillary absorption tubes. After a set time period, the capillary absorption tubes are analysed using a gas chromatograph. The level of tracer found within the capillary absorption tube is indicative of the building's air infiltration rate.