Those of you who may have built or bought a new home in the City of Santa Fe over the last few years may be familiar with the terms ‘HERS Rating’. HERS (Home Energy Rating System) is a tool for measuring the energy performance of a home. It has become the standard method across North America for ranking homes in terms of energy efficiency. Much like the MPG (miles per gallon) rating on a car; a HERS rating describes how energy efficient a home will be. But energy performance is not the only way to quantify a home’s efficiency.