Jake
How close to the old foundation do we want the new foundation?
Jan
Aline
How thick do we want the outside walls to be?
Net Zero standards in Oregon say roofs should be R60 and…
walls should be R-21 cavity insulation + R-5 to R-15 continuous exterior insulation OR…
deep-wall assemblies like 2×8 framing packed with cellulose plus exterior rigid foam.
Zip R sheathing has 1.5“ of exterior insulation and is R6. Works.
Rockwool is about R4/inch, they sell an R23 version for 6” (5.5“) walls and an R30 version for 8” (7.25“) walls. Which do we want? Pretty easy to use doubled 2x4s with a small gap to get that thicker version. Basically the same cost as 2×6 walls, and will provide more sound isolation.
Tony
How tall are the floor trusses going to be?