ASHRAE Level 2 energy audit: what it includes and what data it needs

A Level 2 energy audit is the middle of the three audit levels defined in ANSI/ASHRAE/ACCA Standard 211-2018 (RA2023), Standard for Commercial Building Energy Audits, and it is the level most incentive programs and audit mandates ask for. Level 1 tells you roughly where a building stands. Level 2 tells you, measure by measure, what to do about it and what each measure costs and saves. Level 3 is for the capital projects where a wrong savings estimate would be expensive.

In Canada the levels are the common language of provincial programs. British Columbia's Better Buildings BC, administered by the Ministry of Energy and Climate Solutions and funded through CleanBC, describes Level 2 as building on Level 1 with more detailed energy calculations and a financial analysis of proposed measures. Manitoba's Commercial Energy Audit Program offers incentives for ASHRAE Level 2 or Level 3 audits covering up to 50 percent of audit costs, performed by a pre-qualified consultant. In the United States, New York City's Local Law 87 makes Level 2 the floor for its mandatory audits.

This is for the person who has to commission a Level 2 or prepare a building for one: what the standard requires, what the deliverables look like, the utility data the auditor will ask for, and how to have it ready on day one. The three levels are compared at a higher altitude in ASHRAE energy audit levels 1, 2 and 3.

What Standard 211 is, and what it says about levels

Standard 211 was approved by ASHRAE on April 30, 2018, and by ANSI on May 1, 2018, and reaffirmed in 2023. Its foreword is candid about why it exists: the commercial energy audit industry is largely unregulated, products labeled "energy audits" vary greatly in scope and rigor, and the earlier ASHRAE Procedures for Commercial Building Energy Audits was not written in enforceable language. The purpose is to define the procedures for each level, give owners a common scope of work, and set minimum rigor and reporting.

Three structural points shape everything else. First, each successive level builds on the preceding one, so a Level 2 audit includes every item already required by Level 1, and the Preliminary Energy Use Analysis (the utility bill benchmark) is part of Level 1. Second, it applies to all buildings except single-family houses, multifamily buildings of three stories or fewer, and manufactured housing. Third, the work must be done or supervised by a qualified energy auditor, defined as someone with five commercial building energy audits completed in the past three years, or ten cumulatively, who conducts the site visit, identifies the measures and signs the form in Normative Annex A.

What Level 2 adds over Level 1

The difference is quantification. The foreword states that because Level 1 is less intensive, the energy savings and costs of the measures it identifies are intended to be qualitative. Level 2 replaces that with numbers: a site-specific list of measures, each with an estimated cost, saving and economic metric, plus a breakdown of the building's energy by end use that has to reconcile with what the meters recorded.

That reconciliation is the discipline at the heart of a Level 2. Washington State's building performance rule, which adopts the Standard 211 levels by reference, states it plainly: for a Level 2 audit the sum of the base-case end-use energy estimates must be between 90 percent and 100 percent of the historical energy use. If the end-use model and twelve months of bills disagree materially, something is running that the auditor has not accounted for, and the savings built on that model are suspect.

Level 2 deliverables

• A Preliminary Energy Use Analysis: energy use intensity and energy cost index, benchmarked against peers
• An end-use breakdown (heating, cooling, fans and pumps, lighting, hot water, plug and process loads) reconciled to billed energy
• A measure-by-measure list: annual savings by fuel, cost savings, implementation cost, and simple payback or simple return on investment
• Operations and maintenance recommendations alongside capital measures
• Capital-intensive measures identified for a Level 3 analysis
• The normative reporting forms from Annex C, and a report following the Level 2 outline in Informative Annex D

The forms are not optional paperwork. ASHRAE publishes the mandatory Level 1 and Level 2 reporting forms as an Excel workbook, referenced from Normative Annex C; the foreword explains they give jurisdictions a standardized reporting path, support electronic data transfer, and build in quality control checks on savings estimates. The standard defines simple payback as initial measure cost divided by first-year calculated cost savings, in years.

The utility data a Level 2 needs

The auditor's first request will be for energy data, and Standard 211 sets the floor: benchmarking must use consumption data spanning a minimum of 12 consecutive months and up to three consecutive years, as available. That means every fuel and every meter: electricity, natural gas, and any chilled water, steam, district hot water or propane the building imports, whether or not the owner pays for it. The standard's definition of energy cost is equally broad, covering base, demand, customer, power factor and miscellaneous charges including sales taxes, so the auditor needs the charge lines, not the totals.

Three refinements separate an audit that starts on day one from one that starts with a month of chasing. Interval data, where the utility offers it, shows the load shape and the demand-setting intervals a monthly total hides. Weather normalization with degree days makes a twelve-month baseline comparable to the year the measures will be judged against; the method is explained in weather normalization. And a clean meter-to-building map, with multipliers and estimated reads flagged, lets the end-use reconciliation land inside the 90 to 100 percent band.

Who requires a Level 2

New York City's Local Law 87 is the clearest mandate. It requires buildings greater than 50,000 gross square feet to complete an energy audit and retro-commissioning every ten years and file an Energy Efficiency Report. The implementing rule, 1 RCNY 103-07, sets the level: the audit's scope must be at a minimum equivalent to the procedures, requirements and reporting described for a Level 2 energy audit in accordance with ANSI/ASHRAE/ACCA Standard 211-2018, with the report following the Level 2 outline in Informative Annex D.

Washington State's Clean Buildings rule, WAC 194-50-080, likewise directs covered buildings to perform a Level 2 audit (energy survey and engineering analysis) as defined in ANSI/ASHRAE/ACCA Standard 211-2018 where required. In Canada there is no equivalent national mandate; the levels enter through incentive programs such as the Manitoba and British Columbia examples above. Check the program's own eligibility page before commissioning, since the required level and approved-auditor rules differ by province.

Preparing data so the audit starts on day one

Most of the delay in a Level 2 engagement is not engineering. It is the auditor waiting for bills, then reconciling bills that disagree with each other. The owner controls this part.

1. Assemble 12 to 36 months of bills for every fuel and meter serving the building, including any the tenants pay
2. Extract every field, not just totals: usage, demand, reads, multipliers, rate class and each charge line
3. Flag estimated reads and check that billing periods chain without gaps or overlaps
4. Map every meter to the building, the tenant space and the end use it serves
5. Pull interval data through Green Button or the utility portal where it exists
6. Record gross floor area as the standard defines it

Getting bills from PDF to a reconcilable dataset is its own problem; the difference between re-keying, OCR and field-level extraction is set out in getting clean data out of utility bills. Whatever the method, the test is whether usage for each meter and month ties back to a read, a multiplier and a source page.

When to go to Level 3

Standard 211 adds one procedural step at Level 3 that the lower levels do not have: the qualified energy auditor must conduct a risk assessment for Level 3, supported by informative annexes on building energy model calibration and risk analysis methods. The practical trigger is a single capital measure large enough that a Level 2 estimate is not a safe basis for the decision: a central plant replacement, a full HVAC change, deep envelope work or an electrification project. A Level 3 is scoped to those measures, not the whole building, which is why the Level 2 comes first: it tells you which measures deserve the deeper analysis.

How MartinAI fits

MartinAI reads every field on every bill and meter file for electricity, gas, water and steam, flags estimated reads, checks multipliers and period continuity, and delivers the twelve-plus months of reconciled data a Level 2 auditor needs. The same dataset shows, before any audit is commissioned, which buildings to retrofit first and so where a Level 2 will pay for itself.

A Level 2 audit is where an energy plan stops being a list of ideas and becomes a ranked table of measures with costs, savings and paybacks that reconcile to the meters. The standard defines what the auditor must do. The owner's job is to make sure the data is complete, continuous and correct before the first site visit.