## 3.1 EDR Adjustments

The software calculates an energy design ratings (EDR) as described in Section 2.1.1. The EDR implementation is limited to newly constructed single-family and multifamily dwellings.

To calculate the EDR, the user enters the proposed home with additional inputs for PV, batteries, and other flexibility measures.

The software then calculates the proposed design energy use and the standard design energy use in accordance with the normal compliance rules. Additional annual simulations are performed to determine the reference design energy use, as described in Section 2.1.4.

There are adjustments made to these EDR calculations to address the issue that the 2006 IECC includes efficiency specifications that result in significantly different levels of total energy use in the reference design for gas and electric equipment, and appliances. These adjustments are needed to ensure that homes using gas water-heating equipment and gas appliances are not penalized in the EDR results, as compared to homes using electric water-heating equipment and electric appliances. This adjustment provides EDRs for gas and electric homes that implement a fuel-neutral approach in the reference design total energy use.

Four quantities are reported for the EDR ratings. The EDR of the standard design building is provided to illustrate how the 2019 standard design compares with the reference design. The EDR score of the proposed design is provided separately from the EDR value of installed PV so that the effects of efficiency and renewable energy can both be seen. The final EDR for the proposed building includes both the effects of efficiency and PV.

The EDR values are calculated for each end use and fuel type for the standard and proposed designs. The general form of the adjustment is:

Equation 13

EDR = EU / EU reference x 100

Where:

EU = Proposed or Standard Design Energy Use (kTDV/ft2)

EU reference = Reference Design Energy Use (kTDV/ft2)

Adjustment = 1 for all end uses that are electric; or

Adjustment = Ratio from Table 35 for all end uses that are gas.

#### Table 35: EDR Adjustments by End Use for Gas Fuel Type

Climate Zone | Single-Family | Multifamily
Heating | Domestic Hot Water | Appliances | Heating | Domestic Hot Water | Appliances
1 | 0.85 | 0.37 | 0.57 | 0.83 | 0.47 | 0.56
2 | 0.91 | 0.40 | 0.57 | 0.89 | 0.49 | 0.56
3 | 1.00 | 0.40 | 0.57 | 1.01 | 0.48 | 0.56
4 | 0.92 | 0.44 | 0.57 | 0.90 | 0.51 | 0.56
5 | 0.91 | 0.39 | 0.57 | 0.91 | 0.48 | 0.56
6 | 1.02 | 0.44 | 0.58 | 1.00 | 0.54 | 0.56
7 | 1.09 | 0.43 | 0.57 | 1.23 | 0.52 | 0.56
8 | 1.07 | 0.46 | 0.58 | 1.06 | 0.57 | 0.57
9 | 1.03 | 0.47 | 0.58 | 1.02 | 0.57 | 0.57
10 | 0.98 | 0.46 | 0.58 | 0.95 | 0.56 | 0.56
11 | 0.89 | 0.41 | 0.57 | 0.88 | 0.55 | 0.56
12 | 0.94 | 0.41 | 0.57 | 0.92 | 0.52 | 0.56
13 | 0.92 | 0.44 | 0.57 | 0.89 | 0.53 | 0.56
14 | 0.87 | 0.47 | 0.58 | 0.85 | 0.55 | 0.57
15 | 0.99 | 0.53 | 0.58 | 0.95 | 0.62 | 0.56
16 | 0.70 | 0.39 | 0.57 | 0.67 | 0.47 | 0.56

Source: California Energy Commission

The ratios were calculated by using a prototype analysis once with gas fuel type for space heating, water heating, and appliances, and once with electric fuel types. The ratio is the end-use energy for the EDR reference building run with gas (kTDV/ft2) divided by the run with electric (kTDV/ft2).