Compliance software shall require the user to identify the type of compliance for the project. The compliance software shall require the user to choose one of the following options:

• New Building or Addition Alone. Compliance software may do this by treating an addition alone as a new building, but an addition modeled in this way shall be reported on all output forms as an addition (modeled alone).
• Addition Plus Alteration of Existing Building (if compliance software is approved for this optional capability).
• Alteration of Existing Building (if compliance software is approved for this optional capability).

For each building or separately permitted space, compliance software shall also require the user to identify the scope of the compliance submittal from a combination of the following list:

• Envelope
• Lighting or Partial Lighting
• Mechanical or Partial Mechanical (may include or exclude Domestic Hot Water)

Each combination requires specific assumptions, input procedures, and reporting requirements. Modeling assumptions are documented in Chapter 5 Nonresidential Building Descriptors Reference and Chapter 6 Multifamily Building Descriptors Reference. Reporting requirements are documented in Chapter 4 Content and Format of Standard Reports. Compliance software shall produce only compliance reports specific to the scope of the submittal determined for the run. For example, if the scope is envelope only, only the PRF-01 forms with envelope-only components are produced.

Lighting compliance for a partial compliance scenario may be for the entire building or may be specified for only portions of the building. When the building applies for partial lighting compliance, the space(s) where lighting for the space is unknown or undefined shall be marked as “undefined,” and the compliance software shall use the standard design lighting power for the user-defined space type for both the proposed design and standard design. Under this compliance scope, the entire building shall be modeled, and the compliance forms shall indicate the spaces for which lighting compliance is not performed.

The combination of the above scopes will determine the standard design to which the proposed design is compared. When a scope is excluded from the performance calculation, the standard design will match the proposed for all features covered by that scope. Specific rules for each building model descriptor can be found in Chapter 5 Nonresidential Building Descriptors Reference and Chapter 6 Multifamily Building Descriptors Reference of this manual.

The program shall account for variations in energy use due to the effects of the California climate zones and local weather data. Climate information for compliance simulations shall use the applicable data set in Reference Appendix JA2.

The compliance software shall calculate the hourly energy use for both the standard design and the proposed design by applying a time dependent valuation (TDV) factor for each hour of the reference year. TDV factors have been established by the CEC for residential and nonresidential occupancies, for each of the climate zones, and for each fuel (electricity, natural gas, and propane). The procedures for TDV energy are documented in Reference Appendix JA3. The total TDV for a project consists of the TDV for all efficiency measures (efficiency TDV) and the TDV for all flexibility measures (PV/flexibility TDV). To comply through the performance compliance approach, the total TDV and efficiency TDV of the proposed design must be equal to or less than the total TDV and efficiency TDV of the standard design. This applies to new building, addition alone, addition plus alteration of existing building, and alteration of existing building projects.

The compliance software shall calculate the long-run marginal, hourly source energy use for both the standard design and the proposed design. Hourly source energy assumes utilities meet all RPS and other obligations and is projected over the 30-year life of the building.

The possible bounds for source energy for electricity are about 10,500 British thermal units per kilowatt-hour (Btu/kWh) upper bound (proxy low efficiency power plant) and 0 Btu/kWh lower bound (renewable generation). Delivery losses are the same as the delivery losses used for TDV.

Avoided source energy from incremental renewable generation depends on Renewables Portfolio Standard (RPS) goals. This avoided source energy is represented as an RPS percentage value that increases annually. The avoided source energy can further vary based on the specific resource used, such as wind, solar or energy storage.

Natural gas long-run source energy is based on the percentage of renewable gas used by utilities. Increased use of renewable gas decreases the source energy impact of retail natural gas consumption.

Propane long-run source energy does not vary on annual basis because there are no renewable gas offsets that can be used to support propane. The long-run marginal source energy of propane is constant and considered to be the source energy of propane gas. This source energy is calculated as a direct conversion factor of 100 kBtu/therm.

The hourly source energy provided by the CEC is used to determine compliance. To comply through the performance compliance approach, the source energy of the proposed design must be equal to or less than the source energy of the standard design. This applies to new building and addition alone building projects.

The compliance software shall meet required capabilities and pass applicable certification tests as defined in Chapter 3 Compliance Software Test Requirements. While the vendor’s candidate software does not need to implement every modeling rule in the Nonresidential and Multifamily ACM Reference Manual, all candidate software features, systems, components, and controls that are modeled must follow the modeling guidelines in the Nonresidential and Multifamily ACM Reference Manual. Vendors seeking certification for candidate software programs to be used for Title 24 compliance should clearly state the extent of the capabilities of their candidate software with respect to compliance. Support of a modeling feature includes correctly processing user input, specifying the standard design correctly, applying that information to simulation models, and processing the results.

Any building features or systems that cannot be modeled in a compliance software program shall show compliance using prescriptive forms.