Bonfiglioli Wall – Specific Use Case Feedback/Thoughts – GreenBuildingAdvisor

I am looking at a new home build in Northern MN, Climate zone 7. I am really trying to make this bordering a passive house, but keeping the budget friendly. I have thought up of a wall system and would like some feedback on it. This is heavily based on the Bonfiglioli Wall. I am really looking for durability without moisture issues and a strong above code insulation value.

From exterior to interior:

1. Vertical Ribbed steel siding

2. Horizontal 1×3 furring strips

3. Vertical 1×2 furring strips

4. TamlynWrap Elite (Was going to use Typar house wrap but this may have to do due to availability) with taped seams.

5. 7/16″ OSB Sheathing (5/8″ OSB for a shear resistant wall on a bump out)

6. 2×6 Stud assembly with doubled up unfaced R13 3.5″ thick batts, totaling to 7″ of fiberglass insulation batt thickness.

7. 3/4″ Polyiso R3 laminated foam insulation on studs for thermal break (foam strips only as wide as each stud)

8. 1×2 Furring strips on every stud, sandwiching the foam to the exterior studs.

9. Certainteed Smart Vapor Retarder

10. 1/2″ Lightweight drywall

For the attic insulation, I plan to use regular poly vapor barrier and R60 cellulose blown in.

Originally I was going to use doubled R15 high density batts but I have seen many articles on diminishing returns, doubling the price for the wall insulation doesn’t seem reasonable to make up for the 1.6 % gain roughly. I know that I could do even thicker foam strips however then the insulation thickness would get a little weird and tough to source for the proper depth.

I am also planning to have a pretty heavy focus on air sealing with acoustic caulk in areas and other common practices. Looking to source an air sealing product similar to ECOSEAL™ Plus Sealant from Knauf.

Thanks everyone.