D.C. Mun. Regs. tit. 12, 12-I-G1
Current through Register Vol. 71, No. 44, November 1, 2024
Section 12-I-G1 - GENERALG1.1Performance Rating Method Scope. This building performance rating method is a modification of the Energy Cost Budget (ECB) Method in Section 11 and is intended for use in rating the energy efficiency of building designs that exceed the requirements of this standard. This appendix offers an alternative compliance path for minimum standard compliance per Chapter 1, Section 101.10.6 of Title 12-A DCMR and is provided for those wishing to use the methodology developed for this standard to quantify performance that substantially exceeds the requirements of Standard 90.1. It shall be used for evaluating the performance of all such proposed designs, including alterations and additions to existing buildings, except designs with no mechanical systems.
G1.2Performance Rating.Gl.2.1 Mandatory Provisions. This performance rating method requires conformance with the following provisions:
a. All requirements of Sections 5.4, 6.4, 7.4, 8.4, 9.4, 10.4, and 11 shall be met. These sections contain the mandatory provisions of the standard and are prerequisites for this rating method.b. The interior lighting power shall not exceed the interior lighting power allowance determined using either Tables G3.7 or G3.8 and the methodology described in Section 9.5.1 and 9.6.1.Gl.2.2 Performance Rating Calculation. The performance of the proposed design is calculated in accordance with provisions of this appendix using the following formula:
Performance Cost Index= Proposed building performance / Baseline building performance Both the proposed building performance and the baseline building performance shall include all end-use load components within and associated with the building when calculating the Performance Cost Index.
Informative Note:
1. Neither the proposed building performance nor the baseline building performance are predictions of actual energy consumption or costs for the proposed design after construction. Actual experience will differ from these calculations due to variations such as occupancy, building operation and maintenance, weather, energy use not covered by this procedure, changes in energy rates between design of the building and occupancy, and the precision of the calculation tool. 2. When using Appendix G, the Performance Cost Index (PCI) shall be less than or equal to the Performance Cost Index Target (PCI t) when calculated in accordance with the following: PCIt = (BBUEC + (BPF xBBREC))/BBP
Where:
PCI = Performance Cost Index calculated in accordance with Section G1.2.
BBUEC = Baseline Building Unregulated Energy Cost. The portion of the annual energy cost of a baseline building design that is due to unregulated energy use.
BBREC = Baseline Building Regulated Energy Cost. The portion of the annual energy cost of a baseline building design that is due to regulated energy use.
BPF = Building Performance Factor from Table G1.2.2. For building area types not listed in Table G1.2.2 use "All others." Where a building has multiple building area types, the required BPF shall be equal to the area-weighted average of the building area types.
BBP = Baseline Building Performance.
Regulated energy cost shall be calculated by multiplying the total energy cost by the ratio of regulated energy use to total energy use for each fuel type. Unregulated energy cost shall be calculated by subtracting regulated energy cost from total energy cost.
3. Neither the proposed building performance nor the baseline building performance are predictions of actual energy consumption or costs for the proposed design after construction. Actual experience will differ from these calculations due to variations such as occupancy, building operation and maintenance, weather, energy use not covered by this procedure, changes in energy rates between design of the building and occupancy, and the precision of the calculation tool. TABLE G1.2.2 BUILDING PERFORMANCE FACTOR (BPF)
Building Area Typesa | Climate Zone 4A |
Multifamily | 0.58 |
Healthcare/ hospital | 0.47 |
Hotel/motel | 0.52 |
Office | 0.48 |
Restaurant | 0.48 |
Retail | 0.45 |
School | 0.39 |
Warehouse | 0.48 |
All others | 0.48 |
a. In cases where both a general building area type and a specific building area type are listed, the specific building area type shall apply. GI.2.3 Additions to Existing Buildings. When an addition to an existing building cannot comply by itself, trade-offs will be allowed by modification to one or more of the existing components of the existing building. Modeling of the modified components of the existing building and addition shall employ the procedures of Appendix G; the addition shall not increase the energy consumption of the existing building plus the addition beyond the energy that would be consumed by the existing building plus the addition if the addition alone did comply.
GI.2.4 Alterations of Existing Buildings. Alterations of existing buildings shall comply with the provisions of Section 5, 6, 7, 8, 9, 10, 11, 13 or Appendix G.
G1.3Documentation Requirements. Simulated performance shall be documented, and documentation shall be submitted to the rating authority. The information shall be submitted in a report and shall include the following:
a. A brief description of the project, the key energy efficiency improvements compared with the requirements in Sections 5 through 11, the simulation program used, the version of the simulation program, and the results of the energy analysis. This summary shall contain the calculated values for the baseline building performance, the proposed building performance, and the percentage improvement.b. An overview of the project that includes: the number of stories (above and below grade), the typical floor size, the uses in the building (e.g., office, cafeteria, retail, parking, etc.), the gross area of each use, and whether each use is conditioned space.c. A list of the energy-related features that are included in the design and on which the performance rating is based. This list shall document all energy features that differ between the models used in the baseline building performance and proposed building performance calculations.d. A list showing compliance for the proposed design with all the requirements of Sections 5.4, 6.4, 7.4, 8.4, 9.4, 10.4 and 11 (mandatory provisions).e. A list identifying those aspects of the proposed design that are less stringent than the requirements of 5.5, 6.5, 7.5, 9.5, and 9.6 (prescriptive provisions). f. A table with a summary by end use of the energy cost savings in the proposed building performance.g. A site plan showing all adjacent buildings and topography that may shade the proposed building (with estimated height or number of stories).h. Building elevations and floor plans (schematic is acceptable).i. A diagram showing the thermal blocks used in the computer simulation.j. An explanation of any significant modeling assumptions.k. Backup calculations and material to support data inputs (e.g., U-factors for building envelope assemblies, NFRC ratings for fenestration, end-uses identified in Table G3.1, "1.Design Model," paragraph [a]).l. Input and output reports from the simulation program or compliance software including a breakdown of energy use by at least the following components: lights, internal equipment loads, service water heating equipment, space heating equipment, space cooling and heat rejection equipment, fans, and other HVAC equipment (such as pumps). The output reports shall also show the amount of unmet load hours for both the proposed design and baseline building design.m. Purchased energy rates used in the simulations.n. An explanation of any error messages noted in the simulation program output.o. For any exceptional calculation methods employed, document the predicted energy savings by energy type, the energy cost savings, a narrative explaining the exceptional calculation method performed, and theoretical or empirical information supporting the accuracy of the method.p. The reduction in proposed building performance associated with on-site renewable energy.D.C. Mun. Regs. tit. 12, 12-I-G1
Final Rulemaking published at 67 DCR 5679 (5/29/2020)