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Building Technical Bulletins

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Technical Bulletins provide guidance concerning the specific code interpretations used by the Building Division of Permit Sonoma. They are intended to aid members of the development community, such as design professionals, builders, and others complying with the codes adopted by Sonoma County.

Each bulletin contains an introduction, specific technical details, and illustrations relating to each topic as appropriate. References are provided to the current California state codes, Energy Efficiency standards, Federal and State legislation, and Sonoma County Codes and Ordinances. New bulletins, as well as updates of existing bulletins, are issued periodically.

Comments on the Technical Bulletin series can be directed via email to Nathan Quarles.

Glossary of Code Terms: This glossary contains definitions specific to the Uniform Building Code unless another model code is referenced. The reader is cautioned against the transference or applicability of the definitions contained herein to other divisions within Permit Sonoma.

Projects Submitted 2020 to Current

The list of technical bulletins below is for projects submitted on January 1, 2020 or after only. For projects submitted December 31, 2019 or earlier, please contact Building Plan Check.


  • B-02 Application of Building Code Provisions to Partially Developed Areas in Residential Construction

    The following guidelines are provided as an aid in determining the code requirements for partially developed areas in residential construction such as attic spaces and storage lofts. Attic spaces and similar areas should be clearly identified on the drawings. The intended use of such areas shall be specified on the plans.

  • B-03 Barn Hay Loft Door

    Hay lofts in a barn are similar in character to a loading dock in a warehouse. The Code does not require guardrails on the loading side of a loading dock.

  • B-05 Cable Rails

    The California Building Code requires that residential guardrails have openings such that a sphere 4 inches in diameter (4 3/8 inches at stairways) cannot pass through. Various cable rail configurations are often proposed to minimize the rail system’s impact on the view from the deck.

  • B-06 Chain Link Fence Permit Requirements

    Chain link and wire deer fences are classified as U occupancies. Because a chain link fence is not an occupied structure and is lightweight and has low wind resistance, the hazards associated with such construction is very low. Consequently, in many cases standard details provided by a fencing company can be approved without additional engineering.

  • B-07 Class "A" Roof Requirements

    Sonoma County requires Class “A” roof assemblies on the following types of structures...

  • B-09 Code Requirements for Residential Stairs

    These guidelines apply to residential stair construction Group R-3 or Group U Occupancies under the scope of the California Residential Code.

  • B-10 Concrete Stoop Adjacent to Wood Framing

    To insure proper protection from dry rot and termite damage to raised wood floor systems, the concrete stoop must be isolated from the wood construction.

  • B-14 Residential Special Inspection and Structural Observation

    The purpose of this technical bulletin is to clarify the requirements for special inspections and structural observations based on Chapter 17 of the 2019 California Building Code (CBC) for the construction/alteration of one or two-family dwellings of Group R-3 occupancies and residential accessory U occupancies. Chapter 17 specifies when special inspections or structural observations are required or exempt based on building and/or site characteristics (e.g. height, geometry, construction materials, type of construction, wind/seismic loading, foundation type, etc.). Chapter 17 also allows the building official to require special inspection and structural observation when requested by the building official. This bulletin provides general guidelines of the instances when Permit Sonoma will require special inspection and structural observation.

  • B-21 Required Exit Doors in Garages

    The California Building Code requires that every portion of the building have a code complying means of egress. This bulletin is intended to clarify the requirements for minimum exiting from a residential garage.

  • B-27 Timber Connectors and Fasteners for Use with Pressure-Treated Wood

    Pressure Preservative-Treated Wood and Fire-Retardant Treated Wood can be caustic to zinc coated (or galvanized) steel and cause the metal to deteriorate. Connectors and fasteners utilized with these wood products must be of the correct type. Fasteners of compatible material should be used to install connectors. This requirement does not apply to the typical installation of foundation, hold down bolts, anchor bolts, plate washers, straps, etc. when installed above grade and not exposed to the weather.

  • B-28 When is a Soils Investigation Required?

    The purpose of this technical bulletin is to clarify when a soils investigation is required as part of a building permit application. The requirements below are intended as general policy guidelines.

  • B-29 Residential Wind Design Criteria

    Lateral load design for wind is required by the California Building and Residential Code. The following are the design requirements for residential structures in Sonoma County. Wind speed and exposure category are the first parameters needed to determine the forces a structure should be designed to withstand.

  • B-31 Residential Straw Bale Construction

    Appendix S Strawbale Construction has been adopted as part of the 2019 California Residential Code. An architect or engineer is required for strawbale submittals per the California Business and Professions Code.

  • B-32 Sleeping Cabins (Units)

    Sleeping Units are defined as “A room or space in which people sleep, which can also include permanent provisions for living, eating, and either sanitation or kitchen facilities, but not both.” Sleeping units can be either wood framed, or a canvas structure supported directly on grade or by a constructed platform. Sleeping cabins (units) may be located in state permitted “Special Occupancy Parks” as defined under Section 18862.43 of the Health and Safety Code or at organized camps as defined in Section 18897 of the Health and Safety Code.

  • B-34 Roof Drainage

    Section 1101.12.1 of the California Plumbing Code (CPC) requires roof areas to be drained by roof drains or gutters. Roof drains are defined as “A drain installed to receive water collecting on the surface of a roof and to discharge it into a leader, downspout, or conductor.” Roof drains, gutters, vertical conductors or leaders, and horizontal storm drains for primary drainage shall be sized to accommodate a rainfall rate of 1.5 inches/hour (0.016 gallons per minute / square foot).

  • B-35 Fireplaces

    In the northern part of the Sonoma County, the Northern Sonoma County Air Pollution Control District regulates emission requirements for fireplaces. In the southern part of the county, emission requirements are regulated by the Bay Area Air Quality Management District. The requirements are different in each district.

  • B-36 Plans Requiring Design by Licensed Architect or Engineer

    The purpose of this technical bulletin is to provide information on the types of projects that may be designed by non-licensed individuals and the types of projects that require design by architects and engineers.

  • B-37 Building Permit Application Stamp and Signature Requirements

    The purpose of this technical bulletin is to provide information on professional licensure stamp and signature requirements for building permit application package materials prepared by engineers, architects and unlicensed persons.

  • B-39 Sonoma County Facility Safety Inspections

    The purpose of this technical bulletin is to clarify how sites and facilities owned by Sonoma County should be permitted and inspected when a facility safety inspection is requested.

  • B-40 Special Occupancy Parks v. Organized Camps

    The purpose of this technical bulletin is to clarify the different types of campgrounds in Sonoma County and identify which jurisdiction (the Sonoma County Permit and Resource Management Department [Permit Sonoma] or the California Department of Housing and Community Development [HCD]) has building permit authority.

  • B-41 Residential Pier Foundation Special Inspection

    The purpose of this technical bulletin is to clarify the required inspections for residential pier foundations.

  • B-42 Design Criteria for Bridges

    The following guidelines are provided to clarify design criteria for bridges. The following are addressed: new construction, replacement, and repair.

  • B-43 Foundation Reports for Fire Damaged Structures

    This guideline presents an evaluation methodology for fire exposed concrete members. The aim is to provide a uniform evaluation procedure while meeting applicable standards and applying forensic engineering principles.

  • B-44 Geotechnical Guidelines for Fire Rebuilds

    The following guidelines are provided to clarify geotechnical reporting, observation, and testing requirements specific to foundations proposed to be located in areas where previous foundations and underlying contaminated soils have been removed due to fire exposure.

  • B-45 Hoop House Membrane Structures for Cannabis Cultivation

    The purpose of this technical bulletin is to clarify the permitting and construction requirements for both temporary and permanent membrane structures for Group U (Utility and Miscellaneous) occupancies used for cannabis cultivation. Hoop house membrane structures are used to extend the growing season by creating a protected interior environment.

  • B-46 Cannabis Cultivation and Restrooms

    The purpose of this technical bulletin is to clarify the permitting requirements for proper handling of domestic waste related to various types of cannabis operations. For all cannabis cultivation, some form of waste storage and/or treatment is required. This policy distinguishes between standalone, portable toilets and fixed restrooms, the latter being connected to either an existing on-site septic system or to a sanitary sewer.

  • B-47 Residential Construction in Floodzones

    The purpose of the following information and documents are to clarify procedures used by the Sonoma County Permit & Resource Management Department to enforce provisions of Sonoma County Code Chapter 7B-Flood Damage Prevention, CRC R322-Flood Resistant Construction, and ASCE24-Flood Resistant Design and Construction. These procedures have been in place since January, 1982, when the department first received flood insurance rate maps, floodway maps and the attendant certification requirements.

  • B-48 Vineyard, Cannabis, and Agricultural Structures

    The purpose of this technical bulletin is to clarify various occupancy group classifications and application of code requirements to structures associated with horticulture, livestock, or poultry uses.


  • E-09 Electric Meters

    This technical bulletin is to provide direction to Permit Sonoma staff in regards to the permitting of new utility owned electric meters and electric meter upgrades.



  • P-02 Floor Drains

    Floor drains are considered fixtures under the plumbing code and must, therefore, be connected to the building drain system leading to the method of sewage disposal. Hazardous materials are prohibited from entering the building drain system except for industrial waste which may be treated to remove harmful constituents. The following guidelines are to be used when floor drains are proposed.

  • P-05 Residential Outdoor Showers and Sinks

    The California Plumbing Code requires that fixtures used to receive or discharge liquid must be connected to the building drainage system. The Code prohibits connection of rain water drainage to the building drainage system. The following guidelines apply to outdoor showers, barbeque sinks, pet washing areas, and other dedicated exterior locations where liquid waste is generated.

  • P-09 Island Fixture Venting

    The intent of this bulletin is to clarify the use of special venting for island fixtures, commonly known as loop venting, to be used at other sink locations when structural framing conditions prohibit the standard plumbing vent system from being used.