On Friday January 9th, 2010 ground was broken for the first home attempting Passive House certification in Seattle. Dan Whitmore of Blackbird Builders, llc, a recently certified Passive House consultant, is building the house and was very excited to finally be breaking ground after weeks of delay in permitting. He was able to get his design that includes a fully insulated slab AND footing set on rigid foam insulation approved by the city of Seattle. This was a key step towards the project being able to meet the energy requirements of a Passive House by eliminating thermal bridging between the foundation and ground. Here are the details about the house as Dan describes it:
About the house: it’s a 3 bedroom 2 1/2 half bath with an attached Accessory Dwelling Unit (ADU). The ADU is a 1 bedroom 1 bath apartment on the back. I call it 2 1/2 storeys because the top floor is small, 15.5′ x 32′. Per PHPP the TFA is 1895s.f. Per standard guidelines the building is 2589 s.f. with an additional 380 s.f. of unheated ‘workshop.’ Foundation is 2/3 slab on grade quite similar to the Fairview buildings [a Passive House project in Illinois] the back 1/3 is a traditional stem-wall foundation. The shell is of a modified platform construction: a combination of double-wall and Larsen trusses, depending on the foundation detail below, both are 14″ thick. Roof is of trusses or stick-framed in three separate low-sloped sheds 19″ thick. Heating is to be provided via the fresh air system. I’m planning on using a Recouperator ERV coupled with a hydronic heating coil.
The Passive House Northwest community is very excited to see this project begin and are looking forward to others starting in the near future. A local film crew from The House That Saved The World will be following the project as part of a “Deep Green” TV series they are filming to promote to Public TV. I will be following this project on this blog, and for those of you who wonder how this fits in with my theme of existing resources, remember that even remodels often need areas that are considered new construction. Passive House construction is brand new to our area and at some point we will all need to understand how to tie the new into the old. Follow along as the project unfolds and learn new techniques to meet the Passive House requirements. You can sign up for email updates of this blog on the right side of this page.
*edited 1/11/10 to add link info for The House That Saved The World.