University increases the transparency of building energy performance

The City of Chicago Energy Benchmarking Ordinance requires all buildings in Chicago greater than 50,000 square feet in size to report annual energy consumption using ENERGY STAR Portfolio Manager. UChicago benchmarks 110 buildings in accordance with the ordinance. All resulting energy data is publicly available on the Chicago Energy Benchmarking webpage.

In accordance with that ordinance, the University recently installed 43 placards representing 71 buildings on campus displaying the Chicago Energy Rating and ENERGY STAR® score, if applicable. ENERGY STAR scores represent building energy performance and range from zero to 100. Chicago Energy ratings range from zero to four stars based on comparisons with national median energy use intensities (EUI) for each ENERGY STAR Portfolio Manager property type.

Higher education buildings classified as classroom buildings and laboratory buildings are not eligible for ENERGY STAR ratings. For these building types, the building’s energy use intensity is compared against similar buildings from a national database compiled by the Energy Information Administration (EIA).

For laboratory buildings, the national median scores used for comparison do not account for Chicago’s climate zone (ASHRAE 5A), the required hours of operations, or functional requirements including the number of fume hoods, laboratory area versus office area, and the type of laboratory buildings. For example, a research laboratory building that requires 24×7 operations with a high density of fume hoods and a high percentage of laboratory space in a cold climate will use more energy than a teaching laboratory with a low fume hood density in a moderate climate. The Chicago Energy Rating System does not take these differences into account. To account for some of these additional considerations, the University of Chicago also benchmarks its laboratory buildings against the buildings available in the International Institute for Sustainable Laboratories (I2SL) data set. This data set provides a national median source energy use intensity of 518 kBTU per gross square foot.

Office buildings and residence halls are eligible for ENERGY STAR ratings, and the corresponding Chicago Energy Rating Rule is shown in table 1.

*Note: Any building with ENERGY STAR certification also receives four stars Information from Chicago Energy Rating System

College/university laboratory buildings are not eligible for ENERGY STAR ratings, and the corresponding Chicago Energy Rating Rule is in table 2.

The placard shown in figure 1 is similar to placards posted in buildings throughout campus.

Figure 1: Saieh Hall for Economics Chicago Energy Rating placard.