We're kicking off the month of earth love with a look inside the area's first Passive House. Don't be fooled by the title. It knows how to stand up for itself. It's passive because it doesn't take very much energy to keep the insides a comfortable temperature. It only uses about 10% of the energy needed by a typical home, and it does it all without solar panels. How can that be, you ask? Thick walls, south facing windows, and an almost airtight seal from the roof to the foundation are what make it possible.
The rendering shows that this house is a typical American foursquare and the second picture gives a graphic description of the physics behind a Passive House. Picture three is of the twelve-inch thick walls that show the concrete with foam insulation. The next two pictures are parts of the mechanical system that keep the air fresh and flowing.
The cost for building one of these babies is estimated at about 5-8% more than what a non-passive house would cost. Part of that is for materials and part of that is for the extra labor required for doing things like insulating the foundation and taping up the gaps and joints in the frame. Some of that cost is offset by not having to buy an HVAC system (around $40k) and since the annual utility bills are much lower many consider the cost to be the same as a not-so green home.
This Passive House is designed by the architect David Peabody and built by O'Neill Construction and will be one of the first thirty in the US. There are about twenty thousand Passive Houses already in Europe, but they are ahead of the curve partly because they don't have to combat the heat and humidity that most of the US gets at some point during the year. Ventilation is important in a town that sees 90% humidity for weeks at a time, so the air filtration system is top notch.
A second post later in the week will be for the science nerds and floorplan lovers. Peabody and Co will tell us why a thermal imaging camera is a Passive House's best friend and how O'Neill and his team stayed on top of quality control when dealing with dozens of sub-contractors.
Photos From Peabody Construction/Curbed DC
· Greenhaus [official site]
· Window To The Future [Bethesda Mag]