The US Environmental Protection Agency has developed an energy performance rating to determine the relative efficiency of whole building energy performance. A 100 point rating scale (expressed as a percentage) provides a standard method for ranking estimated or actual energy performance of a design or building. A 75 rating means that a building’s intended performance will be among the top 25 percent of similar buildings.
Building Design
Target Finder lets you select a target rating and provides the estimated energy use intensity (EUI) and cost. The target result is repeatable and consistent and is based on actual building source energy use and not a hypothetical baseline. The Target Finder uses data from Department of Energy’s - Commercial Buildings Energy Consumption Survey1 to determine EUI for a specified space type and building location. The rating and associated energy use intensity can be used early in design to determine an energy budget.
You can also compare the estimated energy use to the target as the project progress. Your estimated energy use calculations or simulation software will produce the estimated consumption for your building design. The energy performance rating will convey the relative efficiency of energy use as compared to benchmarked buildings. Comparing your design to the target tells you if the desired goal is being met. EPA encourages setting your target beyond the ENERGY STAR threshold of 75 because of the opportunity to explore innovative technologies and strategies and rate their effectiveness during the design process.
"Designed to Earn the ENERGY STAR” graphic
EPA has expanded its offerings and recognition to include building design. Architecture firms can now display the "Designed to Earn the ENERGY STAR" graphic to distinguish their projects as among the nation's best in energy performance. Design projects with and an energy rating of 75 or higher are eligible to receive the graphic. Receiving the "Designed to Earn the ENERGY STAR" graphic does not guarantee that the occupied building will achieve the ENERGY STAR label. It implies that the intent is to achieve the ENERGY STAR once the building is fully operating. The graphic is awarded only to building projects that are designed to earn the ENERGY STAR. It in no way implies nor requires that an architect or engineer certify that the building will perform to any specified level. Instead, it indicates that the design has achieved an energy performance rating of 75 or higher on the EPA rating system and that the estimated energy use includes all fuel sources, building systems and equipment loads, and energy efficiency strategies.
The EPA energy performance rating uses the fuel consumption data of existing commercial buildings, which includes the total energy use associated with the building. Therefore, design energy use must include all fuel sources and total estimated energy use for the building design. An incomplete design energy use profile could result in a high but inaccurate rating. Gaps in energy analysis must be addressed in order for the rating to be a useful indicator of future performance. The EPA rating helps designers address the overall expected energy performance for a building design, whereas code compliance may not consider the total energy use, such as all equipment loads, supplemental loads (office equipment, PCs etc), or energy-efficient measures specified in construction documents.
Existing Commercial Buildings
To achieve ENERGY STAR, a building must be occupied for at least one year and generated utility bills and achieved minimum rating of 75. Buildings that meet these criteria are eligible for the ENERGY STAR label for buildings. (Log on to Portfolio Manager to apply for the ENERGY STAR.)
You can track and rate actual energy consumption of your building(s) in Portfolio Manager to evaluate if energy design intent translates into efficient building operation, energy savings and pollution prevention over time. Building commissioning is recommended to ensure that energy performance meets the intended goal.
1CBECS is a statistical survey of building features, energy consumption, and expenditures in US commercial buildings.