A manufactured home has been installed on the NIST campus for ventilation, energy andindoor air quality studies. The primary purposes of the facility are to study mechanicalventilation requirements for U.S. manufactured homes and to investigate the systems used tomeet these requirements. In addition, the building will be used to investigate moisture issues,indoor air quality impacts of combustion appliances, and VOC emissions from buildingmaterials and furnishings. The first phase of this multiyear effort has focused on airtightness,system airflows and air change rates. This paper describes the measurement results includingenvelope and duct airtightness, ventilation system airflow rates, and whole house air changerates under different ventilation configurations and weather conditions. In addition, a modelof the building in the multizone airflow program CONTAMW is presented along withcomparisons between model predictions and measurements of air change rates. The resultsindicate that the envelope and air distribution ductwork are fairly leaky, but not unusuallyhigh for U.S. manufactured homes, and that the predicted air change rates are in goodagreement with the measured values.