Originally Posted by John Galt

Standard wall construction here is 2x6 w/ interior 2x3 horizontal strapping with the air/vapor barrier sandwiched in-between so all electrical is on the inside without penetrating the AVB; R-60 ceiling, triple lowE argon windows, and a heat recovery ventilator. House also has to pass an air leakage test. Basic Cdn R2000 standards are the norm here now. Many add exterior foam over that. Heating must be high efficiency minimum 85%. I built my house to that standard 15 years ago.

2x8 allows too much thermal bridging and isn't permitted.