Diligence is key in building a Passive House. Making sure all the details are incorporated as planned is necessary. When Dan’s windows showed up with the wrong stickers on them there was more than enough heartburn to go around. Windows are a very important part of the Passive House configuration. Figuring out where they are located, how much sun they let in (or keep out), how large they are, what their physical properties are in terms of materials & construction are all very important.
As the truck pulled up Dan noticed immediately that there was a problem. A call to the manufacturer determined that it was most likely a sticker mixup, but just to be sure Dan did not install them until the engineer determined that they were in fact the right windows. Phew! I am happy to report that they are in and I have the pictures to prove it. Dan’s friend Dale even came up from Portland to help put them in. Additionally there is now a set of stairs to the 2nd floor and I was able to go inside for the first time and I took more pictures.
If you notice, the windows are not flush mounted to the outside as you would expect. There is a reason for this. The windows perform better thermally if they are placed closer to the center of the window well. There is a program available from the Lawrence Berkely National Laboratory called THERM that can be used to test for the thermal capabilities of construction materials, primarily windows and after testing the position and types of materials, it was found that where the windows are located within the assembly is an important factor.
With the windows in, the Tyvek and siding going up outside, we are getting close to another Passive House feature – the airtight layer. Dan designed his Passive House to have the airtight layer on the inside of the structure. He will be using OSB over the larsen trusses on the inside, sealed, and then will blow in dense pack fiberglass insulation into the cavity. Once the doors are in and any other openings are covered it will be time for the blower door test. If you want to be sure you don’t miss any updates, you can register for email notification on the right hand side of the page.