D.C. Mun. Regs. tit. 12, 12-I-Z2
Minimum performance requirements for building energy use intensity have been set to ensure maximum energy efficiency prior to adding renewable energy generation. The building and its site shall be designed and constructed to meet the mandatory prescriptive requirements in sections Z2.1, Z.2, Z.3, Z.4, and Z.5.
Applicant shall submit, with the building permit application, permit documents with data and calculations sufficient to ascertain compliance with the net-zero energy performance target for buildings and their sites, using predictive modeling. Predictive modeling shall use a source energy unit of measurement, expressed in kBtu/ft2/yr, based on the use of the Zero Energy Performance Index (zEPI) as outlined in Section Z2.1.1. In a mixed-use building, all uses shall be included in demonstrating compliance, and an area-weighted calculation method shall be used to account for each use.
Zero Energy Performance Index, zEPI. Building design shall demonstrate a zEPI of 30 or lower as determined in accordance with Equation 1.
zEPI = 50.4 X (EUIp/EUI) (Equation 1)
Where:
EUIp = The annual energy use of the building in source kBtu/ft2, for the proposed design of the building and its site, calculated in accordance with Section Z2.1.2, not taking into account any on-site or off-site renewable energy.
EUI = The annual energy use of the building in source kBtu/ft2 for a baseline building and its site, calculated in accordance with Section Z2.1.2, not taking into account any on-site or off-site renewable energy.
Annual energy use indices. The EUIp of the building and building site, and the EUI, shall be calculated in accordance with Appendix G to ASHRAE 90.1-2016, as modified by Sections Z2.1.2.1 and Z2.1.2.2, and approved mod eling guidelines published by the Department in administrative bulletins. The annual energy use shall include all energy used for the building systems and its anticipated occupancies.
Additional Modeling Rules and Procedures. Modeling inputs shall be in accordance with the COMNet Rules and Procedures Manual
Electricity. In calculating the annual energy use indices, consistent units shall be used for electric energy use, converting the electric energy use measured at the utility meter or metered point of delivery from kWh to kBtu. KWh shall be converted to kBtu by multiplying the annual electric energy use, in kWh, by 3.412 kBtu/kWh and multiplying the result by the dimensionless conversion factor found in Table 1.
TABLE Z2.1.2.2
ELECTRICITY GENERATION ENERGY CONVERSION FACTOR
BASED ON EPA eGRID SUB-REGION
eGRID 2010 SUB-REGION ACRONYM | eGRID 2010 SUB-REGION NAME | CONVERSION FACTOR |
RFCE | RFC East | 3.28 |
Building thermal energy performance shall comply with Sections Z2.2.1 through Z2.2.2.
Annual heating demand. Building design shall demonstrate a maximum annual heating demand of 42 kBtu/ft2 iCFA/yr (4.8x104 kJ/m2iCFA/yr).
Annual cooling demand. Building design shall demonstrate a maximum annual cooling demand of 6.4 kBtu/ft2 iCFA/yr (7.3x104 kJ/m2iCFA/yr).
Where there is more than one building on a site, each building shall comply with Sections Z2.2.1 and Z2.2.2 or the combined demands of all the buildings on the site shall comply with Sections Z2.2.1 and Z2.2.2.
Assignment of energy to multiple buildings on a site. For building sites employing district energy systems and with multiple buildings, the energy use associated with the building site shall be assigned to each building proportionally to the gross floor area of each building as a fraction of the total gross floor area of all buildings on the building site. Where energy is derived from either renewable or waste energy, or both sources, either located on the building site, within individual buildings, or on individual buildings and delivered to multiple buildings, the energy so derived shall be assigned on a proportional basis to the buildings served, based on each served building gross floor area. Energy delivered from renewable or waste energy sources located on or within a building shall be assigned to that building.
Exception: Where it can be shown that energy to be used at the building site is associated with a specific building, that energy use shall be assigned to that specific building.
Where the applicant chooses to utilize Appendix Z as the path of compliance with the Energy Conservation Code-Commercial Provisions, the owner shall engage the services of, and designate on the building permit application, a registered design professional who shall act as the registered design professional in responsible charge of building energy simulation. Building energy simulation services engaged by the registered design professional shall be certified by an approved accrediting entity as determined by the code official. As authorized by the code official, the owner is allowed to designate a substitute registered design professional who shall perform the duties required of the original registered design professional in responsible charge of building energy simulation. The owner shall notify the code official, in writing, whenever the registered design professional in responsible charge of building energy simulation is changed or is unable to continue to perform his or her duties.
All systems shall be commissioned in accordance with this section and the Energy Conservation Code-Commercial Provisions. Energy systems commissioning and completion shall be performed for the following systems and their associated controls:
* Building envelope;
* HVAC (both mechanical and passive systems as well as HVAC controls);
* Lighting, daylighting, and lighting control systems;
* Domestic hot water systems; and
* Renewable energy systems.
A whole building pressurization testing shall be conducted in accordance with Section 11.3.1.2.4(a) of the Energy Conservation Code - Commercial Provisions to measure the airtightness of the building envelope. The owner shall verify that the airtightness specified in the final approved predictive energy model is achieved in the field by providing the code official with a copy of the test results before the final Certificate of Occupancy is issued.
D.C. Mun. Regs. tit. 12, 12-I-Z2