Compliance costs can vary widely based on which measures people choose to install. To produce a useful estimate range, we assume people will choose the measures that let them comply with the target score for the lowest cost.

For the low end of the range, we assume a home will be able to choose from any and all measures in the measure table, including the ones that assume that an appliance or roof are at the end of their life and need to be replaced anyway. From those choices we model all the possible combinations of measure choices that meet the target score and find the one with the lowest cost.

For the high end of the range, we assume a home will choose from only the generally applicable measures, and not the ones that are contingent upon needing an appliance replacement or a new roof in order to make economic sense. From those choices we model all the possible combinations of measure choices that meet the target score and find the one with the lowest cost. With less measures to choose from costs tends to be higher, and sometimes significantly higher.