Flatrock Passive House: A Passive House in Newfoundland

In the previous post I presented the results from two blower door tests.  The blower door results from the garage testing can be used to determing the heat load required by the building.  We can think of the heat loss as a sum of two components:  Heat lost through conduction and heat lost due to infiltration.  This is a highly simplified method and only partially describes the physical behaviour of heat loss.  For example it neglects to account for thermal mass effects, treats conduction as a one dimensional phenomena, ignores convection currents, ignores the thickness of the walls, etc.  However, this simplified method typically overestimates the size of the required heat source so its good enough for this purpose. Calculating yearly demand is a matter of breaking the structure up into individual components.  First I calculated the area of each component using my construction drawings.  The product of area, R-value, and 24 hours/day gives the heat lost per degree day.  The website w

I probably mentioned before that I would cringe every time we had to drill out through the air barrier.  Every time I drill through it I would wonder if I could get back to the level of air tightness I achieved on the initial blower door test.  With almost 21 penetrations for electrical, plumbing, mechanicals including the HRV and wood stove, it seemed like it would be impossible to achieve the level of air tightness required to get the efficiency I wanted.  However, with good air sealing details, the task wasn't as hard as I originally thought it would be.  Custom gaskets, lots of acoustical sealant,  and 3M tape just crush any chances of air getting in! Previously installed conduits where wires were routed were filled with spray foam.  Plumbing sewer pipes that were vented to the outside were tape sealed.  The air vent for the wood stove and the chimney thimble were sealed with plastic and tape. The biggest problem area was routing wires through to the garage.  Installing con

 We had a plan of attack from the beginning.  That plan involved erecting all exterior service walls first and then framing the interior walls later.  The plans call for 24" o.c. studs for the service wall.  That's about the only details we had to go by except how to terminate around windows and doors.  The framers worked pretty quickly at framing the interior.  The service walls were almost completed after two days of work.  To strengthen the interior petitions and service walls, we install staggered blocking at half height help prevent the wall studs from bowing, warping and twisting (Picture 1).  Now its starting to look like a house!  Since we would be installing drywall returns around all windows I opted for adding the 1/2" drywall return slot to the window frames at the time they were made.  To make the lives of the drywall installers easier, the rough stud openings had to align with the drywall returns so shims wouldn't have to be used (Picture 2).  We framed

Attics are cold in the winter and warm in the summer.  Since they are vented through the soffit they are also drafty spaces.    The attic could become an energy sink without lots of insulation and good air sealing details.  We are at a point in construction where we have to start penetrating out though the air barrier and into the attic.  I find this scary but its another reminder that we are progressing nicely. With our blower door test measuring air tightness of the air barrier at 0.45 ACH50, I cringe every time somebody suggests that we have to drill a hole in it!  This being said, I knew it would be inevitable.  So we move forward with plumbing and wiring details.  Although we placed all the washrooms on one side of the house, it was pretty much impossible to tie everything into one main vent stack.   There service cavity on the ceiling is 2x4 strapping on face so there just isn't enough room to route each vent to a common place and terminate them together before penetrating