Local Law 87/09 energy audits must comply with the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standards for a Level 2 energy audit. The purpose of the audit and associated report is to identify ways to improve a building’s energy efficiency, from system upgrades to operational and maintenance measures.

The audit entails a review of the property’s energy bills to analyze natural gas, fuel oil, and electricity use from a one- to three-year period. Much of this information can be gathered from the utilities data submitted to the City under the new benchmarking law, Local Law 84/09. In addition to looking at the utility use within the building as a whole, the review includes individual billing records for a minimum of 10 percent of all apartments, including at least one of each apartment type.

The utilities data compiled determine the building’s Energy Utilization Index (EUI), which is compared to the EUIs of similar buildings. An energy model can then be developed for the building, and based on the EUI, performance targets established—for example, increasing energy efficiency by 20% over the next three years.

The energy audit report identify ways to improve a building’s energy efficiency.

The energy audit itself is a visual survey of the following base-building systems: exterior envelope (facades and roofs); heating, ventilation, and cooling systems; electrical and lighting; elevators; fans, motors, and pumps; and any other components that affect energy use. The audit also covers common areas, including lobbies, hallways, stairwells, basements, storage, recreational rooms, gyms, etc. In addition, the audit team will perform a limited inspection of approximately 10 percent of the apartment interiors, looking at energy-related items such as radiators, fan coil units, air conditioners, PTAC (packaged terminal air conditioner) units, vents, and lighting and plumbing fixtures. 

The audit includes non-destructive tests, such as infrared scans (to detect heat loss and water infiltration), domestic water pressure and temperature readings, air pressure measurements, and ventilation flow rates. To supplement visual observations, the audit firm may request investigative probes to better determine the underlying construction and conditions of areas not easily visible or accessible, such as a structural roof deck or a plumbing chase.

To obtain a better understanding of the building’s energy usage, it is helpful for the audit firm to interview building management, maintenance staff, and residents. While the analysis of the building’s utilities bills yields an overall view of energy consumption, discussions with those who live in and/or work for the building can provide more detailed information and insight into patterns of energy use, such as apartments/floors that are too hot or cold, drafty spaces, banging radiators, leaks, lack of hot water, peak usage times, and actions that waste energy, such as keeping doors and windows opened, leaving lights on, letting water run, etc.

After completing the audit, the audit team will present you with a report that includes a prioritized list of recommendations for improving energy efficiency in four categories:

Low-cost/No-cost Improvements: These are measures that require little or no funding yet provide immediate or short-term payback. Examples: Replacing missing or damaged insulation around pipes and other hot surfaces, tuning and cleaning heating and hot water systems, and installing low-flow aerators on faucets. 

Another example of a low-cost improvement is sealing gaps and cracks with caulking and weatherstripping to prevent warm air from escaping and cold air from entering the building. The Department of Energy reports that air leakage accounts for anywhere from 5% to 40% of a building’s heating and cooling costs. Air leaks also allow moisture and pollutants to infiltrate a building.

Prudent Capital Improvements: Cost effective measures that require substantial funding but provide short-term payback. Examples: Replacing inefficient lighting throughout the building and replacing heating system controllers and steam traps.

Major Capital Improvements: Extensive system upgrades that provide longer-term payback. Examples: Replacing older boilers with high-efficiency units or installing a combined heat and power (cogeneration) system. 

Health and Safety Improvements: Measures that do not directly affect energy efficiency but do improve residents’ comfort, health, or safety. Examples: Installing emergency lighting, balancing ventilation, and removing hazardous materials.

The audit report should also list anticipated budget requirements and an associated energy cost savings analysis (sometimes referred to as a Savings Investment Ratio, or SIR) for each recommended measure. In addition, the report should include an analysis of what would be required for more intensive capital improvements outside the retro-commissioning measures (see below).