Review Methodology
Types of the Review Checks
The review checks described in this manual have the following focus areas:
- General requirements of 90.1 Energy Cost Budget and Performance Rating Method
- Examples include verifying that an approved simulation tool and weather file was used.
- Specified systems and components reported in the Compliance Form reflect design documents
- Examples include verifying that the rated wattage of lighting fixtures and the number of lighting fixtures specified in various spaces reported in the Compliance Form are consistent with the lighting plans and schedules; that the reported HVAC system types, capacities, and efficiencies reflect design documents, etc.
- Specified systems and components meet the mandatory requirements in 90.1 Sections 5 - 10
- Examples include verifying that the specified lighting controls meet mandatory requirements in Section 9; that the efficiency of the specified HVAC systems meets or exceeds minimums provided in Section 6, etc.
- The applicable mandatory requirements for many systems and components are listed in the Compliance Form. Compliance with these requirements is automatically verified by these QC checks.
- Budget/baseline systems and components reported in the Compliance Form reflect requirements of the 90.1
Energy Cost Budget Method or Performance Rating Method
- Examples include verifying that the lighting power density, HVAC system types, thermal and solar properties of the envelope reported in the Compliance Form for the budget/baseline design are established correctly.
- In many cases, the relevant parameters are automatically populated in the Compliance Form by applying the rules of the ECB or PRM to the reported “triggers”. For example, project climate zone is one of the triggers that determine the auto-populated U-values of the baseline exterior walls. The key triggers are typically listed in the check description.
- The auto-populated budget/baseline parameters may be accepted without further review once the triggers are verified and if the auto-populated values are not over-written.
- Some defaults may be over-written, for example when 90.1 rules have exceptions that are not automated in the Compliance Form. The over-written defaults are shown in brown font in the Compliance Form and may require additional verification.
- Simulation inputs reflect systems and components reported in the Compliance Form
- Examples include verifying that lighting power density or mechanical system type, capacity, and efficiency are modeled as reported in the Compliance Form. For example, if the Compliance Form indicates that the baseline exterior lighting power is 1,700 W, the check would confirm that it matches the exterior lighting input in the simulation tool.
- Such checks apply to both the baseline/budget and proposed design models.
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Simulation outputs are consistent with systems and components reported in the Compliance Form
- Baseline/budget and proposed design models include numerous inputs in addition to those reported in the Compliance Form. These undisclosed inputs, as well as modeling mistakes, may have a significant impact on the compliance outcome. Confirming a reasonable correlation between inputs and outputs is an effective way of identifying potential issues. For example, if air leakage through the envelope is reported to be the same in the baseline and proposed design, an output report may be used to verify that infiltration heating and cooling loads are the same in the baseline (budget) and proposed models.
- Some of these checks are automated in the Compliance Form. For example, since both non-coincident interior lighting peak demand and the rated lighting fixture wattage are reported, projects with non-coincident peak demand exceeding the rated lighting wattage are clearly erroneous. Similarly, projects with no electric space heating systems reported in the Compliance Form but with electricity used for space heating based on the simulation reports are automatically flagged.
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Simulation outputs are consistent with the selected benchmarks
- The check may be applied at the whole building level, for example to confirm that the modeled energy use intensity (EUI) of the budget design is similar to a typical EUI for buildings of similar type in the same climate zone minimally compliant with the given edition of 90.1. A similar approach may be used to verify EUI of individual end uses such as lighting or space heating.
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The benchmarks for the budget/baseline and proposed designs are selected in Table 4 of the Energy Performance
Summary tab of the Compliance Form. The default benchmarks are set based on
DOE/PNNL prototype models
(the prototype models) as described below:
- Proposed design documenting minimum code compliance: the prototype model of the appropriate building type and climate zone, compliant with the same edition of 90.1.
- Proposed design documenting performance above code: the prototype model of the appropriate building type and climate zone, compliant with 90.1 2019.
- ECB budget design: the prototype model of the appropriate building type and climate zone, compliant with the same edition of 90.1.
- PRM baseline: the prototype model of the appropriate building type and climate zone, compliant with 90.1 2004.
- For mixed-use buildings, the benchmark energy use is calculated as an area-weighted average.
- The configuration and key operating assumptions of the prototype models are summarized in the scorecards which can be downloaded at the DOE Building Energy Codes Program website.
- Refer to 90.1 2022 Section G3.3 Performance Calculations for Other Alterations for notes of caution for alterations subject to Section G3.3 (i.e., Minor Alterations).
- The default limits by which the modeled EUIs can deviate from the benchmark EUIs before a flag is triggered for the corresponding review check on the Quality Control Checks tab are included in Table 6 of the Performance Summary tab from the proposed design, and in Table 7 for the baseline/budget design and may be customized.