For as long as homes have been built, builders have had to contend with the effects of rain and humidity on the homes they construct. But as houses have gotten tighter and more energy efficient, either by choice or by increasing code requirements, moisture management has become an even bigger issue.

More air sealing and insulation in the exterior walls of homes can lead to problems in wall cavities that are less able to dry when they become wet. The moisture characteristics within highly efficient homes can change too, due to lower air infiltration rates and decreased operation of the heating and cooling equipment. All of these factors may have significant effects on the wall cavity moisture levels, condensing surface temperatures, and moisture content of wood members.

The NAHB wants to assess the effects, if any, of energy-efficiency measures on moisture performance, particularly in the wall systems of homes. To this end, the NAHB has engaged the NAHB Research Center to conduct monitoring across the country on homes constructed to higher energy-efficiency targets. The results will provide the NAHB and the research participants with valuable real-world performance data.

The Research Center is seeking 20 or more new energy-efficient homes, representing the various U.S. climate zones, to participate in this field monitoring study of wall moisture performance. Qualifying homes should be occupied in order to capture the effects of occupants’ day-to-day habits. Sensors will be installed in the selected energy-efficient homes to measure relative humidity, temperature, and moisture content of wood-frame materials. Monitoring will continue for a minimum of 15 months following installation of the equipment.

Builders who participate in this research program will not be disclosed in the reporting. All sites will be reported only by general geographical location. Builders who qualify can provide multiple homes for participation in the study.

Manufacturers of energy-efficient products and systems are also invited to participate in this study by sponsoring test sites with homes built using their technologies. Sponsors can choose whether or not they want to make their participation public information.

If you are interested in participating, please visit the NAHB Research Center’s website— —for more details, including qualification requirements.