Earlier this year, the World Record Academy awarded a home in Dillingham, Alaska with the record for the Tightest Residential Building.

In a video that documents the blower door test, the home’s owners and residents, Dr. Tom Marsik and Kristin Donalson, who designed and built the extremely insulated building, explain their motivation to push the limits of green building methods. The blower door test, which used a special attachment to get the most accurate reading, pressurized the building and then measured the flow that was needed to maintain the difference in pressure from the outside.

The key energy features of the home include its small size (600 square feet with two bedrooms and one bathroom), 28 inch thick walls, an extremely tight building envelope (0.05 ACH50), ventilation via a Heat Recovery Ventilator (HRV). The majority of the heat needed by the home is derived from internal heat gains (from lighting, appliances, passive solar, and body heat).


Only about 35 gallons of heating oil is needed each year to make up the difference between internal heat gains and needed heat. Windows are triple-pane, argon-filled with fiberglass frames. Appliances are Energy Star rated, lighting is supplied by CFLs, and plumbing fixtures are low-flow.

While extra insulation cost around $20,000 of the estimated construction costs of $169,500, the owners expect to save about $4,000 per year in energy costs.


The home design was based on an educational tool that was developed by the University of Alaska Fairbanks (UAF) Bristol Bay Campus Sustainable Energy Program, Passive Office, which was an experiment in energy-efficient building construction. Marsik is an assistant professor of sustainable energy at UAF.

Extensive details about the home’s specifications and construction can be found on the Alaska Energy Wiki where you can find links to more images and articles about the record-setting Dillingham house.