The complexity of an energy audit and the potential for savings vary with the size, intricacy, and use of a building.
San Francisco Environment Code Chapter 20 sets a high standard: audits must meet or exceed the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Procedures for Commercial Building Audits, with larger facilities required to receive a more rigorous evaluation than smaller facilities. The audit requirements are:
- Buildings 50,000 square feet and larger: ASHRAE Level II - An “intermediate” survey and energy analysis
- Buildings 10,000 to 49,999 square feet: ASHRAE Level I - A basic energy analysis
For a summary of what each level of effort entails, ASHRAE has provided the Department of Environment with this excerpt from the Procedures for Commercial Building Audits, which can be downloaded here. The excerpt is provided by ASHRAE solely for the purpose of completing audits as required by the Existing Commercial Buildings Energy Performance Ordinance.
The full Procedures for Commercial Energy Audits are available directly from ASHRAE.
Large facilities and buildings with complex systems are encouraged to undergo retrocommissioning. Retrocommissioning is the systematic, detailed examination of all systems and operations in a building to both ensure they are operating as designed, and to identify opportunities for operational and capital improvements. Retrocommissioning will fulfill the audit requirement, but is a voluntary best practice that is most common in buildings seeking LEED certification or the ENERGY STAR. The California Commissioning Collaborative provides an excellent guide to selecting a retrocommissioning provider.
All building owners must have at least 12 months between the date they are notified an audit is required, and the date when the first Confirmation of Energy Audit is due. Notification of audit requirements is sent to the party listed by the Office of the Assessor Recorder as the contact for property tax, and the owner is responsible for filing a Confirmation of Energy Audit on or before the due date assigned to the parcel. Important: The due dates for benchmarking are not related to the due dates for an energy efficiency audit.
Energy audits which were completed in 2008, or after, may be used to fulfill the audit requirement, provided that the audit is an evaluation of the whole building, meeting the applicable ASHRAE Level of Effort, or retrocommissioning. If only portions or specific systems in the building have been evaluated, or the energy efficiency evaluation was prior to 2008, then a current and comprehensive audit is required. Audit due dates for individual buildings have been established on a rolling deadline, determined by SF Environment, so that buildings of a given size do not all have the same deadline.