John asks: What does a commercial building energy audit typically cost? My building is 55,000 square feet and have 4 tenants including my company, who owns the building. I see there are levels of audit so what are the cost differences between them?
The purpose of a building energy audit is to identify areas where building systems and equipment could be improved upon through updated operation or replacement with the end goal of saving energy and reducing the utility costs associated with operating a building.
Three levels of energy audits(1) have been identified that serve as general categories for identifying the level of information and confidence in the results that may be anticipated from a building energy audit analysis.
Level I Energy Audit
The Level I Energy audit is the first step in developing a priority list for buildings that may qualify for a Level II or Level III Energy audit, or in cases where a large portfolio of buildings exists.
A Level I audit involves assessing a building’s energy cost and efficiency by analyzing energy bills and briefly surveying the building, accompanied by the building operator (if applicable). Level I analysis identifies and provides a savings and cost estimate of low-cost/no-cost measures and lists potential capital improvements that merit further consideration, along with an initial judgment of potential costs and savings. The Level I audit is more applicable when there is some doubt about the energy savings potential of a building, or when an owner wishes to establish which buildings have the greatest potential for energy savings (ASHRAE, 2007).
Level II Energy Audit
A Level II audit (Energy Survey and Analysis) includes a more detailed building survey and energy analysis. In a case where submetering is not present, energy usage for individual building systems or components could be estimated (fans, pumps, lighting, plug load, etc) based on installed equipment efficiencies and general rules of thumb. This breakdown would help the auditor to determine which efficiency improvements are most favorable in terms of ROI and help make better simple payback calculations for presentation to the owner. Level II analysis identifies and provides the savings and cost analysis of all practical measures that meet the owner’s constraints and economic criteria, along with a discussion of any effect on operation and maintenance procedures. It also lists potential capital-intensive improvements that requires more thorough data collection and analysis, along with an initial judgment of potential costs and savings (ASHRAE, 2007). As the ASHRAE handbook states, the level of detail associated with this type of audit is acceptable for most cases, and it is therefore the most common.
Level III Energy Audit
The main difference between a Level II and III audit is that the Level III is built to include detailed analysis of capital-intensive modifications with a level of confidence high enough for major capital expenditures.
All that being said, to give a general ballpark cost I would typically ask an owner about the lighting, HVAC, domestic hot water, metering and other building systems currently in place.
But since all I have to go on here is square footage, I’d say very rough ballpark figures for your building could be in the range of $8-12,000 for a Level II Audit, including energy usage benchmarking with ENERGY STAR Portfolio Manager. Differences for Level I to Level III could also vary, but might be something on the order of ±20%. These numbers are definitely very general, and since every project is different fees can vary pretty widely.
1 (Mazzucchi, 1992)