You are here

Home » Services » Facilities & Leasing » Energy Program » Energy Star Portfolio Manager » Evaluation of Non-Rated Building Types

Evaluation of Non-Rated Building Types

-

Many state agency and college buildings are not ENERGY STAR Portfolio Manager Rated Building Types. For instance, offices and warehouses are Rated Building Types, but college classroom buildings and prisons are not. RCW 19.27A.190 required Enterprise Services to evaluate non-rated building types by July 1, 2011, to determine which of these buildings need preliminary energy audits.

Site Energy Use Intensity (EUI)

Site Energy Use Intensity (EUI) will be used to identify buildings which may benefit from an energy audit. The EUI is the annual energy use of each building per square foot. If the building is on a campus with shared utilities, and is not yet individually metered, the campus EUI will be used. The building or campus EUI may be compared to the average EUI in the State portfolio for that building or campus type, or the National Average Site Energy Use Intensity (EUI) of a similar building type in the EIA Commercial Buildings Energy Consumption Survey (CBECS). The National Average EUI is useful as a rough comparison, although buildings with unique energy demands may vary from the average.

Using Building Energy Performance Distributions to Find Savings Opportunities

The data collected by EPA to create Rated Building Types is useful for estimating the potential energy savings available in non-rated buildings. For example, buildings in the lowest-performing quartile use more than 35% more energy than the average building. A small number of worst performers use more than twice as much energy as the average. It is likely that non-rated building types have similar performance distributions. For this reason, buildings using more energy than the average make good candidates for preliminary energy audits.

Some building types use more energy. Food Service and Science Buildings are examples of energy intensive buildings. A high EUI does not mean the building is inefficient. However, the financial benefit of reducing the energy use of a science building by just 10% may be the same as reducing the energy use of an office building by 30%. 5-10% savings can often be found in no-cost or low-cost operational or controls adjustments. For this reason, all buildings with high EUI make good candidates for preliminary energy audits.

Based on the probable energy performance distribution of non-rated building types, and the greater financial benefit from small percentages of energy savings in buildings using more energy per square foot, preliminary audits are recommended for all non-rated buildings using more energy than the average of comparable buildings.

Colleges-- Half of the community and technical college campuses reporting in the State portfolio have EUI under 80. Campuses using less than 80 kBtu/sf-yr routinely benefit from DES Energy audits that produce cost effective energy conservation measures. Comprehensive preliminary audits are recommended for community and technical college campuses with campus average EUI greater than 80. 

Universities – Comprehensive preliminary audits are recommended for university campuses with campus average EUI greater than 120 (all universities are already conducting audits).

Large Agencies -- DES recommends that agencies with large numbers of buildings, such as DOT, DOC and DSHS, initiate comprehensive preliminary audits of campuses which use more energy than the average campus in that agency.

Small Agencies -- Agencies with small numbers of buildings will not have enough data to find averages. Preliminary audits are recommended for non-rated building types over 10,000 gsf with EUI greater than 80.

When all state agency and college buildings are individually metered and benchmarked, the building energy use data may be specific enough to identify buildings with lower EUI that would benefit from energy audits. For instance, colleges can compare classroom buildings or gymnasiums across the state portfolio, taking into account differences such as hours of use. At this time, there are not enough state agency and college buildings separately metered and benchmarked to allow this level of analysis.

List of Recommended Preliminary Audits, To Be Completed by July 1, 2012

For all agency or college buildings not benchmarked in Portfolio Manager by July 1, 2011, a preliminary audit is recommended, to be initiated by November 1, 2011 to allow collection of energy data during the winter heating season. The Energy Services Company (ESCO) performing the preliminary audit will put facilities into Portfolio Manager (will benchmark buildings) for the agency or college for a nominal fee. Buildings or campuses will be taken off the list recommending an audit if benchmarking shows they use less than the average EUI as described above and in the table below, and if the preliminary audit found no cost effective energy conservation measures. The benchmarked status of all agency and college buildings as of July 1, 2012 will be reported to the legislature in a report on December 1, 2012.

If your agency or college is on the list of recommended preliminary audits, please request an audit from DES Energy, or follow the DES ESPC Guidelines to procure the audit from an Energy Services Company. You may request to be taken off the list if a comprehensive audit was done within the last 5 years, and all cost effective measures implemented.

For more information contact:

Department of Enterprise Services
Energy Program
Donna K. Albert, PE, MCE, CEM, LEED-AP
Phone: (360) 902-7248
E-mail: donna.albert@des.wa.gov