The National Institute of Standards and Technology (NIST) constructed the Net-Zero Energy Residential Test Facility (NZERTF) to support the development and adoption of cost-effective NZE designs and technologies. Among the key objectives of the facility design was creating a healthy and comfortable environment for the assumed occupants by providing adequate outdoor air ventilation and reducing indoor contaminant sources. Building material source control guidelines were implemented to minimize the use of products with urea-formaldehyde resin and to utilize products with relatively low volatile organic compound (VOC) emissions. Indoor and outdoor concentrations of formaldehyde and acetaldehyde were measured approximately monthly during two years of house operation. Real-time formaldehyde concentration and energy measurements were also used to validate the indoor air quality (IAQ) and energy predictions of a coupled CONTAM-EnergyPlus model of the house. The validated model was then used to evaluate the IAQ and energy impacts of different outdoor air ventilation rates. The results of this work demonstrate the need for appropriate product selection (source control) and mechanical ventilation, especially in homes with relatively airtight envelopes.