modern wooden frame houses with good insulation are very efficient at keeping heat/moisture where it needs to be kept. I am in the process of building new house and recently had same research - build like we used to build house where I am from (eastern europe, brick and mortar) or use something everybody is doing. turned out that this stick frame structure with foam insulation is actually much more efficient.

Attached garages are typically is separated from the rest of the house conditioning space. I do insulation of the garage, but only because I plan to work there. Plus water heater I am installing is actually heat pump, so it should cool garage down a bit.