I live in a 1,200-square-foot two-story house. This summer, on blazing hot days, the entire house was kept cool by a cheap 5,000-BTU air conditioner in one of the upstairs rooms. Ceiling fans downstairs drew the cold air throughout the house. Even when it was 100-plus degrees outside, when you entered the house you were hit with a blast of cold air.

Tiny 5,000-BTU A/C (my house)

Ceiling fan (my house)

Super-thick concrete walls (my house)

This is only possible because this energy-efficient house was built with concrete walls that are nearly one foot thick. It requires very little energy to cool the space (or warm it with the built-in radiant floor heating system).

The efficiency gains are even more impressive in an actual Passive House, promulgated by Germany's Passive House Institute. 

Wayne Turett's Passive House in Greenport

A Passive House combines thermal insulation with triple-glazed windows and heat-recovering ventilation systems, and are so well-sealed that they can dispense with heating systems altogether; warmth is captured from sunlight coming through the windows and, believe it or not, the normal body heat of residents inside, as well as that given off by appliances.

Wayne Turett's Passive House in Greenport

Wayne Turett's Passive House in Greenport

Wayne Turett's Passive House in Greenport

"A Passive House thus consumes about 90 percent less heating energy than existing buildings and 75 percent less energy than an average new construction."

Wayne Turett's Passive House in Greenport

Wayne Turett's Passive House in Greenport

Wayne Turett's Passive House in Greenport

A Passive House is something that you really need to see (and feel) to believe. And this month you can, depending on where you live.

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The Passive House Institute is sponsoring their annual International Passive House Open Days from November 9th thru the 11th, where owners of the structures open their doors to visitors. There's a map of all of the participating locations here, and for those of you near Long Island, New York, architect Wayne Turett will show you his personal home (pictured above) in Greenport. 

You can RSVP here.