Napa County Municipal Code Ch. 15.12 Building Code

Footnotes:

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Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed the former Ch. 15.12, §§ 15.12.010—15.12.300, and enacted a new Ch. 15.12 as set out herein. The former Ch. 15.12 pertained to similar subject matter. See the Ordinance List and Code Comparative Table and Disposition List for complete derivation.

For the purpose of establishing proper regulations for building construction, the following two codes are adopted and made part of this Chapter by reference, subject to the modifications made herein:

A. The 2025 Edition of the California Building Code, Volumes I and II, including Appendices C, I, J, and P, hereinafter referred to as "building code," which is based on the 2024 International Building Code adopted with modifications by the State of California as Title 24, Part 2 of the California Code of Regulations.

B. The 2025 Edition of the California Residential Code including Appendices BF, BB, BJ, BM, and CI, hereinafter referred to as "residential code," which is based on the 2024 International Residential Code adopted with modifications by the State of California as Title 24, Part 2.5 of the California Code of Regulations.

(Ord. No. 1516, § 10, 12-9-2025)

Each section of the building or residential code designated in the succeeding sections of this chapter shall be changed to read as set forth in this chapter, except that where the modification is a deletion only, the deletion shall be noted without setting forth the text of the section.

(Ord. No. 1516, § 10, 12-9-2025)

Section 105.2 of the building code is amended to the extent set forth below:

Building

7. Painting, papering, tiling, carpeting, cabinets, counter tops, and similar finish work not resulting in dimensional changes between any of the following: walls, sinks, plumbing fixtures, electrical outlets, built in appliances and service panels.

Section R105.2 of the residential code is amended to the extent set forth below:

Building

6. Painting, papering, tiling, carpeting, cabinets, counter tops, and similar finish work not resulting in dimensional changes between any of the following: walls, sinks, plumbing fixtures, electrical outlets, built in appliances and service panels.

(Ord. No. 1516, § 10, 12-9-2025)

Sections 105.5 of the building code and R105.5 of the residential code are amended to read as set forth in Section 15.04.070 of this code.

(Ord. No. 1516, § 10, 12-9-2025)

The functions of the board of appeals referred to in Sections 1.8.8 and 113 of the building code and Section R112 of the residential code shall be performed by the unified board of appeals constituted pursuant to Section 15.04.100 of this code and no separate board of appeals shall be created.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.1 of the building code is amended to read in full as follows:

446.1 Scope. In addition to other occupancy and construction requirements of the building code, special provisions for the occupancy and construction of subterranean space for winery facilities in natural or manmade caves, whether new or an addition to an existing cave shall be in accordance with this section.

(Ord. No. 1516, § 10, 12-9-2025)

A. Section 446.4 of the building code is hereby amended to modify the following definition:

TYPE 3 WINERY CAVES. Natural or manmade caves used for the storage and/or processing of wine at a winery facility. Type 3 winery caves are accessible to the public on guided tours or by hosted events. Any cave or portion of a cave that exhibits any of the following is also considered to be a Type 3 cave:

1. Contains an area classified as a Group A occupancy.

2. Contains an area classified as other than Group F or S occupancy.

3. Is constructed or furnished with any amount of combustible materials not otherwise permitted in this section.

B. The following definitions are added to Section 446.4 of the building code:

HOSTED EVENTS. Any event held within the winery cave and attended by non-employees. This includes, but is not limited to: wine tasting; banquets; receptions; seminars; or any other event attended by people that are not employees of the winery. Hosted events are only allowed in caves or portions of caves that are Type 3.

TOURS. Whenever people who are not employees of the winery pass through or otherwise occupy a winery cave, for any purpose, including the tasting of wine. All tours must comply with 446.8.1 requirements for public tours.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.5 of the building code is hereby amended to read as follows:

446.5 Permits. Permits for the excavation, occupancy, construction, alteration, enlargement, or repair of Type 1, 2, and 3 winery caves, including all retaining walls, associated equipment, and facilities, shall be per Chapter 1 and Appendix J.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.7.3 is hereby added to the building code to read as follows:

446.7.3 Noncombustible construction: Type 1 and Type 2 winery caves must be constructed of noncombustible materials throughout.

Exception: Doors and other openings in exterior and interior walls and partitions may be made of combustible materials unless otherwise limited by this code.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.8.4 is hereby added to the building code to read as follows:

446.8.4 Noncombustible contents. Contents of Type 1 and Type 2 winery caves shall not include combustible contents other than wine itself.

Exceptions:

1. Wooden barrels or tanks. Combustible storage vessels filled with wine, or to be filled with wine in the immediate future; may be empty as part of the wine processing and storage. Long term storage of empty wooden barrels or tanks is prohibited.

2. Wooden barrel supports that are constructed of at least 2-inch nominal dimension lumber.

3. Small quantities of combustible materials needed for immediate or frequent use in the processing and storage of wine, or to service and maintain restrooms, wine laboratories, or wine libraries, are allowed.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.8.5 is hereby added to the building code to read as follows:

446.8.5 Prohibited equipment. No hydrocarbon powered mechanized equipment shall be used within the wine cave. Powered equipment shall conform to the requirements of 2022 California Fire Code Section 4003.3.3.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.8.6 is hereby added to the building code to read as follows:

446.8.6 Hazardous materials storage. Only hazardous materials storage directly related to and essential for wine processing operations in the cave is allowed. Hazardous materials storage shall be maintained in compliance with Chapter 50 of the California Fire Code.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.8.7 is hereby added to the building code to read as follows:

446.8.7 Special requirements for Type 3 winery cave. Caves or portions of caves classified as Type 3 shall be provided with an automatic sprinkler system compliant with Section 903.

(Ord. No. 1516, § 10, 12-9-2025)

Section 446.10 of the building code is hereby amended to read as follows:

446.10 Fire alarm systems. An approved manual fire alarm system conforming to the provisions of Section 907.2.1 shall be provided in:

1. Type 1 or Type 2 winery caves containing restrooms, wine laboratories, or wine libraries.

2. All Type 3 winery caves.

(Ord. No. 1516, § 10, 12-9-2025)

Editor's note— Ord. No. 1450, § 11, adopted Dec. 17, 2019, repealed former § 15.12.140 in its entirety which pertained exit length travel in winery caves and derived from Ord. No. 1350, § 6, adopted 11-23-2010, eff. 12-23-2010; Ord. No. 1416, § 14, adopted 11-22-2016.

Section 446.16 is hereby added to the building code to read as follows:

446.16 Emergency Communication. Emergency Responder Communication Coverage in accordance with 2022 California Fire Code Section 510 is required in all caves.

(Ord. No. 1516, § 10, 12-9-2025)

A. For the purposes of this section "building area" shall have the meaning set forth in chapter 2 of the building code, except where modified for Accessory Dwelling Units by Government Code Section 65852.2. "Existing" is defined as "previously permitted and approved building areas that: 1) are attached to the structure under review; and 2) maintain all structural elements in place, before, during and after construction".

B. Section 903.2 of the building code is hereby amended to read as set forth in Section 903.2 of the fire code, as amended in Section 15.32.090 of this code.

C. Section R309.1 of the residential code is amended to read as follows:

R309.1 Townhouse automatic fire sprinkler systems.

An automatic sprinkler system shall be installed in townhouses.

Exception: An Automatic sprinkler system shall not be required where additions or alterations are made to existing townhouses that do not have automatic systems installed and where the addition or expansion increases the existing building area by 49% or less. Addition or expansion that will increase the existing building area by 50% or more shall be required to retrofit the entire building.

D. Section R309.2 of the residential code is amended to read as follows:

R309.2 One- and two-family dwellings automatic fire systems.

An automatic sprinkler system shall be installed in one- and two-family dwellings, guest cottages and detached structure containing sleeping rooms.

Exceptions:

1. An Automatic sprinkler system shall not be required where additions or alterations are made to existing buildings that do not have automatic systems installed and where the addition or expansion increases the existing building area by 49% or less. Addition or expansion that will increase the existing building area by 50% or more shall be required to retrofit the entire building.

2. Accessory Dwelling Unit, provided that all of the following are met:

2.1.

The unit meets the definition of an Accessory Dwelling Unit as defined in the Government Code Section 65852.2.

2.2.

The existing primary residence does not have automatic fire sprinklers.

2.3.

The accessory detached dwelling unit does not exceed 1,200 square feet in size.

2.4.

The unit is on the same lot as the primary residence.

(Ord. No. 1516, § 10, 12-9-2025)

Editor's note— Ord. No. 1450, § 13, adopted Dec. 17, 2019, repealed former § 15.12.170 in its entirety which pertained to a height requirement for standpipes and derived from Ord. No. 1350, § 6, adopted 11-23-2010, eff. 12-23-2010.

Section 907.1.6 is hereby added to the building code to read as follows:

907.1.6 False alarms. A false alarm shall mean the receipt by the fire department of an audio or visual alarm or signal from an automatic fire alarm device set off by causes other than the occurrence of a fire. Alarm users are allowed three false alarm calls in a 365 day period. A service fee of $100 shall be imposed for the fourth false alarm, $250 for the fifth false alarm, and $500 for each subsequent false alarm after the fifth.

(Ord. No. 1516, § 10, 12-9-2025)

Editor's note— Ord. No. 1478, § 22, adopted Nov. 29, 2022, repealed § 15.12.190, which pertained to Section 907.4.2.1—Location, and derived from Ord. No. 1350, § 6, adopted Nov. 23, 2010.

Editor's note— Ord. No. 1450, § 14, adopted Dec. 17, 2019, repealed former § 15.12.200 in its entirety which pertained to the location of fire alarms and derived from Ord. No. 1350, § 6, adopted Nov. 23, 2010.

Editor's note— Ord. No. 1450, § 15, adopted Dec. 17, 2019, repealed former § 15.12.210 in its entirety which pertained to alarm requirements for public and common use areas and derived from Ord. No. 1350, § 6, adopted Nov. 23, 2010.

Section 1505.11, of the building code and Section R902.1.3 of the residential code are hereby added to read in full as follows:

1505.11 and R902.1.3 All roof coverings shall be a minimum of Class A roof assemblies and roof coverings.

(Ord. No. 1516, § 10, 12-9-2025)

All wood burning devices, including but not limited to fireplaces and wood stoves, permanently installed indoors in new construction or any remodel, shall comply with the requirements of the Bay Area Air Quality Management District's Regulation 6, Rule 3, as the same may be amended.

(Ord. No. 1516, § 10, 12-9-2025)

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.240, which pertained to Section R337.6.3—Ventilation openings on the underside of eaves and cornices and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.250, which pertained to Section R337.7.5—Open roof eaves and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.260, which pertained to Section R337.7.6—Enclosed roof eaves and rood eave soffits and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.270, which pertained to Section R337.20—Underside of appendages and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.280, which pertained to Section R337.10.3.1—Accessory building requirements and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.290, which pertained to Section R337.10.3.2—Attached miscellaneous structure requirements and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.

Editor's note— Ord. No. 1516, § 10, adopted December 9, 2025, repealed § 15.12.300, which pertained to Section R337.10.3.3—Detached miscellaneous structure requirements and derived from Ord. No. 1468, § 1, adopted 5-18-2021; Ord. No. 1478, § 24, adopted 11-29-2022.