The #IceBoxChallenge is a contest. It’s also a public science demonstration that invites the public to discover the benefits of high-performance buildings.

High-performance buildings are reliable, affordable, comfortable buildings that keep the indoors in and the outdoors out. They stay comfortable and quiet throughout the year, including through summer heatwaves, winter storms and power outages.

The buildings use up to 90% less energy for heating and cooling than other buildings do, while maintaining good indoor ventilation and air quality. They are easy to maintain. They are also affordable to build, own, live in and work in.

An experiment in high-performance building design and construction


The Ice Box Challenge comprises two small structures. One is built to the 2016 California Energy Code, and the other is built to the super-insulated, air tight Passive House Standard. Each Ice Box contains 250 pounds of ice. The Ice Boxes are left outside in the late summer sun for 5 days. Then they are opened and the amount of ice left in each box is measured. How much ice is left indicates how well each Ice Box keeps out the summer heat.

Passive House California and the Ice Box Team is running the Ice Box Challenge, with support from members of the local construction industry, the North American Passive House Network, and the City of Oakland.