What is a Passive House?

 

In late July, a new house built by Beracah Homes will rise on Addison Road in Prince George’s County, Maryland. This house is unique in several ways. Most notably, it is pre-certified to be a Passive House, the world’s strictest building standard for energy.  It is also designed to be a model for future affordable housing designs, and a guide for the future of residential construction in general.

The Passive House program was developed in Europe over the past 20 years, and there are now more than 40,000 Passive House projects in Germany alone. The program is in still in its early stages in the U.S., but it’s starting to catch on. For instance, New York City has just passed an ordinance requiring that all new construction be built to the Passive House standard.

Why would you want to build a Passive House? Well, they use 80% to 90% less energy for space heating and cooling than do conventional new buildings in the U.S.  But they cost an average of 8% to 15% more than conventional homes in terms of initial capital investment, depending upon the size and climate.

How are they different than traditionally built homes? An integrated approach to design through energy modeling is the key to the design of these buildings. Their construction is virtually airtight, and uses about twice as much insulation as buildings built to the current energy codes. Windows are triple-glazed with thermally insulated frames. These improvements reduce heating and cooling loads to the point where traditional heating and cooling systems are unnecessary, thus recapturing a lot of the costs generated by the more robust building envelope. (The house at Addison Road, for example, will be heated by the same amount of energy used by a hair dryer, and cooled by the equivalent energy of a car air conditioner!)

Less quantifiable, but equally impressive, are the health and comfort benefits of Passive Houses. Because of the airtight envelope, when the house is closed up during heating and cooling seasons, a continuous ventilation system provides constant fresh air to all spaces. This reduces levels of asthma and other chronic respiratory ailments, as well reducing days absent from school and work.

Passive Houses are more comfortable because the sealed building envelope allows no surface in the house to vary in temperature by more than four degrees. This means there are no drafts and no layers of air from floor to floor. People who build Passive Houses for energy reasons are surprised and delighted by the year-round comfort they enjoy.

In our next blog, learn how Beracah Homes became involved in an upcoming unique Passive House design!

Beracah Homes specializes in custom designedhomes in Delaware, Maryland, Virginia, Pennsylvania or New Jersey.  Located in Greenwood, DE, Beracah Homes is a pioneer in "off-site, stick-built" construction.