What is the best wall construction in North Carolina?
I have clients wanting to build a LEED (hopefully Silver) home in NC and I keep going around about the best wall system to use that is energy efficient, cost effective and structurally sound. We (builder, structural engineer and I) have decided on a 2×4, 24″ O.C. staggered wall design that is off set 12″ between studs and 2″ front to back. Top/sill plates are 2×6’s. 5/8″ sheetrock on interior, 1/2″ OSB exterior with a double layer of TYVEK DrainWrap taped and sealed then spider lath and stucco finish (looking for low maintenance finish). We looked into 1″ foam on the outside and the structural engineer didn’t like the strain it puts on the connectors to hold the weight of the stucco. Staggering the 2×4’s is to reduce the thermal bridging. I was concerned about a vapor barrier and was thinking about adding 15# tar paper to the OSB. The lot is tight and the spaces inside can’t get any smaller so I was looking for an option that wasn’t super thick. Any advice would be appreciated.