Buildings represent a major link between society and the environment
and are an essential element in any strategy designed to
promote environmental sustainability. In the United States, where
humans spend nearly 90% of their time indoors [1], buildings are
responsible for roughly 41% of all carbon emissions [2]. Without
significant interventions, CO2 emissions from US buildings are
expected to increase faster than any other sector over the next two
decades with commercial building emissions projected to grow
the fastest, at 1.8% each year through 2030 [3]. To combat this
alarming projection, the United States has set a federal target of
reducing total national greenhouse gas emissions by 80% by 2050
[4]. As buildings account for approximately 40% of all US energy
consumption [5], one strategy for achieving this ambitious emissions
reduction goal is to motivate widespread building-sector
energy conservation. This approach has spurred numerous initiatives
that promote energy efficiency, including: efficiency rating