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 the all walls without the king studs either side of the window. Using a square inside of the drywall return, the studding around the windows was placed after the walls were erected. The rough stud opening now provides a nailing surface for drywall.
Exterior service walls sit on top of 1.5" EPS foam strips (Picture 3). This prevents thermal bridging through the bottom wall plate to the concrete stem wall foundation. Long 5" screws (#10) were used to screw the service wall to the 2x8" exterior stud wall at the top and bottom plates. In order to ensure that the walls were straight, shims were placed behind the screw locations and the wall was straightened using string lines. Once straightened, the wall was secured by driving the screw though the top plate of the service walls, through the OSB and into the exterior wall plates.
The stairs: I had been dreading this because I had never worked on a staircase before. My plan was to build the rough staircase so it could be capped later. Quite a bit of planning had to go into this. I had to ensure that all the components were offset from the walls to account for drywall and a skirt board as well as ensure that I had room for railings, etc. Another reason that I was dreading the staircase was because the house plans called for a winder stair in order to make up the number of stairs required for the 9' ceilings. The winder looked confusing. However, once I investigated further I determined that 2 risers and a landing worked fine. The rest of the stair case just worked out. The rise and run meet code and will be very similar in "feel" to the staircase in my current house.
There were no details in the plans about connecting interior walls to the service walls. Blocking on-face seemed like a good method to get more insulation into the service wall and it also provided a place to nail drywall also (Picture 4). Corners were framed so insulation could be inserted into the corner.
The plans currently call for batt insulation but I may decide to go with dense pack fibreglass. I find the thought of insulating the wall myself using batt insulation a little daunting. Fitting the batting around all of the wires and pipes seems like it would be much more time consuming than its worth. BIBS seems to be a better option. I will revisit this option in a couple of weeks as we make more headway.
The weather has turned cold...then warm...then cold again. While working at the house I have had much time to assess how the house behaves. With no heat source in the house and many cloudy days, the house cooled a lot. One day when it turned 14 C outside, I walked into the house...it was like an icebox! I could see my breath! 24 hours later it felt just as cold and I could still see my breath despite 24 hours of warmer than seasonal temperatures. Having the sun shining the past couple of days has been welcomed. It has warmed the space significantly. Despite not having any attic insulation yet, I am pleased with the way the house responds to exterior temperature swings. It really goes to show that air sealing plays a huge part in energy savings.