Most estimates of energy savings and cost-effectiveness of building energy conservation measures are based on engineering calculations or computer simulations. A compilation of utility billing data in occupied buildings is an important. complement to these estimates and provides feedback to building owners and operators on how well conservation retrofits work in practice. We have compiled energy consumption data on over 300 nonresidential buildings that have been retrofitted with energy conservation measures. For the 94% of the buildings in our sample that saved site energy, median savings were 31 kBtu/ft² a year (350 MJ/m² a year). In this paper we discuss the benefits and limitations of using whole-building metered data to evaluate energy savings attributable to conservation measures. Submetered energy consumption data are scarce; we present examples and discuss the additional benefits such data can provide to the building operator in assessing the impacts of specific retrofit measures.

Units: Dual