Napa County Municipal Code Ch. 15.29 Energy Code

Footnotes:

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Editor's note— Ord. No. 1516, § 16, adopted December 9, 2025, repealed the former Ch. 15.29, and enacted a new Ch. 15.29 as set out herein. The former Ch. 15.29 pertained to similar subject matter and derived from Ord. 1297, § 7, 2007; Ord. No. 1350, § 12, adopted 12-23-2010; Ord. No. 1388, § 21, adopted 1-16-2014; Ord. No. 1416, § 25, adopted 11-22-2016; Ord. No. 1450, § 25, adopted 12-17-2019; Ord. No. 1478, § 40, adopted 11-29-2022 and Ord. No. 1493, §§ 1—8, adopted 7-23-2024.

The 2022 Edition of the California Energy Code, adopted by the State of California as Title 24, Part 6 of the California Code of Regulations, is adopted and made a part of this code by reference.

(Ord. No. 1516, § 16, 12-9-2025)

Section 100.0.(e).2.D is amended to read as follows:

D. Single-family buildings.

i. Sections applicable. Sections 150.0 through 150.1 apply to newly constructed single-family buildings.

ii. Compliance approaches. In order to comply with Part 6, newly constructed single-family buildings must meet the requirements of:

a. Mandatory measures: The applicable provisions of Sections 110.0 through 110.10, and 150.0; and

b. Either:

(i) Performance approach: Sections 150.1(a) and (b); or

(ii) Prescriptive approach: Sections 150.1(a) and

Exception to Section 100.0(e)2Diib: Seasonally occupied agricultural housing limited by state or federal agency contract to occupancy not more than 180 in any calendar year.

(iii) Designers, builders, licensed contractors, professionals, or other owner designees of newly constructed single-family buildings shall provide all owners with the option of installing a stationary storage battery system and/or all-electric appliances.

(Ord. No. 1516, § 16, 12-9-2025)

Section 100.1.(b) is modified by adding the following definitions:

CERTIFIED ENERGY ANALYST is a person registered as a Certified Energy Analyst with the California Association of Building Energy Consultants as of the date of submission of a Certificate of Compliance as required under Section 10.103.

FREE-STANDING ACCESSORY DWELLING UNIT is a detached building that is not intended for sale separate from the primary residence, except pursuant to Government Code Sections 66340 et seq., on a lot that is zoned for single-family or multifamily use, located on the same lot as an existing dwelling, and does not exceed 1,200 square-feet of total floor area.

(Ord. No. 1516, § 16, 12-9-2025)

A new section 120.9.(d) is added to read as follows:

120.9(d) Where systems using gas are installed, dedicated circuits at the main building panel shall be provided with sufficient power to support future conversion of all fossil fuel-fired service water heating appliances to electric appliances.

(Ord. No. 1516, § 16, 12-9-2025)

The first two paragraphs of Section 150.0 are modified to read as follows:

SECTION 150.0 - MANDATORY FEATURES AND DEVICES

Single-family residential buildings shall comply with the applicable requirements of Sections 150(a) through 150.0(v).

NOTE: The requirements of Sections 150.0(a) through 150.0(v) apply to newly constructed buildings. Sections 150.2(a) and 150.2(b) specify which requirements of Sections 150.0(a) through 150.0(v) also apply to additions or alterations.

Section 150.0.(t) is modified to read as follows:

(t) Heat Pump Space Heater Ready.

Systems using gas furnaces to serve individual dwelling units shall include the following:

1. A dedicated 240-volt branch circuit wiring shall be installed within 3 feet from the furnace and accessible to the furnace with no obstructions. The branch circuit conductors shall be rated at 30 amps minimum. The blank cover shall be identified as "240V ready". All electrical components shall be installed in accordance with the California Electrical Code.

2. The main electrical service panel shall have a reserved space to allow for the installation of a double pole circuit breaker for a future heat pump space heater installation. The reserved space shall be permanently marked as "For Future 240V use".

3. A designated exterior location for a future heat pump compressor unit with either a drain or natural drainage for condensate.

(Ord. No. 1516, § 16, 12-9-2025)

A new section 150.1.(b).1.C is added to read as follows:

In addition, the total source energy (EDR1) of the Proposed Design Building shall be less than the EDR1 of the Standard Design building by a compliance margin of 13.

EXCEPTION 1 to Section 150.1(b)1.C. A Free-Standing Accessory Dwelling Unit.

EXCEPTION 2 to Section 150.1(b)1.C. If the Certificate of Compliance is prepared and signed by a Certified Energy Analyst, compliance margin may be reduced by one point, but in no event shall be less than zero.

(Ord. No. 1516, § 16, 12-9-2025)

Editor's note— Ord. No. 1516, § 16, adopted December 9, 2025, repealed § 15.29.080, which pertained to Electric vehicle (EV) charging for new single-family units and duplexes and derived from Ord. No. 1493, § 6, adopted 7-23-2024.

A new section 160.4.(g) is added to read as follows:

Systems using gas water heaters that do not serve individual dwelling units shall include dedicated circuits at the main building panel with sufficient power to support future conversion of all fossil fuel-fired service water heating appliances to electric appliances.

(Ord. No. 1516, § 16, 12-9-2025)

Section 170.1 is modified to read as follows:

SECTION 170.1 - PERFORMANCE APPROACH: ENERGY BUDGETS

A building complies with the performance approach if the TDV energy budget calculated for the Proposed Design Building under Subsection (b) is no greater than the TDV energy budget calculated for the Standard Design Building under Subsection (a). Additionally, the energy budget, expressed in terms of source energy, of a newly constructed low-rise multifamily building (less than four habitable stories) shall be at least ten percent (10%) lower than that of the Standard Design Building.

EXCEPTION 1 to Section 170.1. If the Certificate of Compliance is prepared and signed by a Certified Energy Analyst, the compliance margin may be reduced to by one percentage point, but in no event shall be less than zero.

(Ord. No. 1516, § 16, 12-9-2025)