Beth Freeman called the Denver Building Department to ask about their new requirements for energy calculations on single family residences. We haven’t had to submit them in the past, but we’d heard that some builders had.
The word from Denver is that you do not need to do energy calculations on dwellings that are framed with 2×6 exterior walls, only those that are framed with 2×4 exterior walls. They’re assuming that you fully insulate the 2×6 wall with R-19 or R-21 insulation.
We typically call out R-21 batt insulation as a minimum wall insulation in our houses.