Flatrock Passive House: A Passive House in Newfoundland

Energy use in a building scales with air infiltration.  Decreasing air infiltration can have a huge impact on heating costs.  The plot in this article ( http://www.bluegreengroup.ca/blog/page/19/ ) illustrates things nicely.  Heating energy decreases linearly with decreasing infiltration while conduction losses through the insulation change little with air infiltration.   A tighter air barrier has several implications.  It leads to lower energy bills and it also leads to a more resilient structure that is less susceptible to moisture.   In addition, balanced mechanical ventilation provides fresh air more effectively than random infiltration and is a controlled route for energy capture/release through an HRV/ERV. Infiltration is typically measured with a blower door test.  A fan blower is placed in a door to the exterior.  The fan is then turned on and the differential pressure it creates causes the house to leak from exterior to interior (depressurization) or vice versa (pressurizati

With the date for our blower door test set within the coming week, we had some major work to complete with air sealing around the windows and doors.   Like all of the details for the air barrier, there is a redundant system for air sealing.  First, the gap between the window and the buck gets a good bead of spray foam.  This will provide some air sealing as well as some insulation to the gap.  Next a backer rod is installed.  Finally the backer rod is caulked to the door jambs/header and the window buck.  Overall its not a hard detail to implement...unless theres not enough space between the window frame and the buck. When the windows were installed, we worked to ensure there was an even space all the way around.  Don't trick yourself into thinking that framing is accurate.  It is not.  Once a square window goes into a framed opening we quickly saw that the bucks weren't as square as the windows.  We had to rob space at one corner of the window in order to get an even space a

In the previous post we were installing the OSB air barrier on the 2x8 stud walls.  The drawing specifies that OSB be installed on the interior of the 2x8 stud wall. Once all joins are caulked with acoustical sealant and then taped, the OSB will act as an air barrier and will also serve as a vapour retarder. Before attempting to install OSB on the ceilings we narrowed down our game plan.  We quickly decided that lifting heavy sheets and attaching them to the ceiling using muscle power and a dead man support was out of the question.  Our local Princess Auto had a drywall lift on sale so we bought it.  We started in one corner of the building.   One person on a ladder guiding the other where to push the drywall lift loaded with a sheet of OSB worked great.  Our first sheet was cut so that the edge of the sheet could be nailed under the underside of the truss.  Using a framing nailer armed with 2 3  /8" nails was the way to go for attaching the sheets.  A hammer and nails was just