Six techniques for R-40 Whole Wall values - including Double Stud Walls, TJI and Exterior Foam solutions

The December / January 2010 edition of Fine Homebuilding features an article by partner Bruce Coldham, AIA, on R-40 Wall Systems.

Based on an exploration he did originally for the Moomaw house, this article survey a variety of wall systems designed to achieve R-40 whole wall value.  Methods include the double stud wall, Larsen truss, a Passive House inspired TJI-framed wall, an exterior Spray Foam model, exterior foam board, and a manufactured SIP wall.

Bruce discusses construction methods, air sealing and drainage plane concerns, and a variety of Pros and Cons for each method, including applicability to new construction and retrofit situations. Helpful color drawings by the FHB team complement the article nicely.