Yeah, you get hosed on insulation if you buy a spec build. Custom homes are often built better, but come at a premium. Larger townhouses -- say, 2500sqft & up

Yeah, you get hosed on insulation if you buy a spec build. Custom homes are often built better, but come at a premium. Larger townhouses -- say, 2500sqft & up -- are often zones more reasonably, at least here, such that heating/cooling can be managed with more granularity. But doing it really requires multiple units, not a single big unit.