| > Modern codes have moved back to 2x4, then they put continuous foam on the outside Codes do allow for only external insulation, but it it also possible to have some exterior "continuous insulation" with the remainder being in the wall cavity. The thicker the exterior insulation, the trickier it can be to attach it to the wall and then also have mechanical fasteners for your external cladding. * https://www.buildingscience.com/documents/insights/bsi-001-t... * https://www.buildingscience.com/documents/building-science-i... However, AIUI, using 2x6s reduces the number of studs needed and so would generally reduce the cost on average from both a material and labour perspective (even if 2x6s are slightly higher each). * https://www.buildingscience.com/documents/insights/bsi-030-a... * https://buildability.ca/wp-content/uploads/2017/05/M400-Adva... * https://www.energystar.gov/ia/home_improvement/home_solution... * https://www.protradecraft.com/article/advanced-framing-dos-a... And it's not like it's a new technique: it's been around for (at least) forty years. |