|Spray foam in cavities, box beam; Rigid XPS at headers|
In this super-tight building envelope design, all walls and roof surfaces have continuous rigid foam insulation, and the wood-framed walls and roof also have cavity insulation. The continuous insulation (CI) material is Extruded Polystyrene (XPS) and has an R-value of about 5 per inch. There is R-5 on wood walls, R-10 on basement walls, and R-20 on all roofs. The cavity insulation, for the most part, is open-cell spray foam with an R-value of about 3.6/in and is located between all exterior 2x4 wood walls studs and between 2x roof rafters and wood roof trusses. Closed cell spray foam was used in one location (the main floor box beam) and that has an R-value of about 6.5/in.
|Recessed lights placed in soffits, not in building envelope|
|If only cavity insulation is used, there would be thermal bridges/no insulation at each wall stud|
I am very pleased about this project and the team that is working to create a house "built as all houses should be built", as the independent energy inspector stated today. (speaking from an Energy Code Compliance standpoint)
|Raised-Heel Scissor truss allows for lots of insulation|