Chapter 19.14

BLOCK STRUCTURE

Sections:

The Sonoma Municipal Code is current through Ordinance 13-2025, passed December 3, 2025.

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Title 19 Integrated Development Regulations and Guidelines | Sonoma Municipal Code

• 19.14.010 Purpose of chapter.

• 19.14.020 Block design standards and guidelines. 19.14.030 Neighborhood commercial development.

• 19.14.040 Lot sizes.

This chapter provides city standards for the layout of proposed blocks within new subdivisions, including minimum lot size requirements. The guidelines and standards set forth in this chapter are intended to:

• A. Promote a connected community and ensure public safety by continuing the historic grid system;

• B. Ensure that new subdivisions emulate historic development patterns in terms of block sizes;

• C. Preserve significant natural features;

• D. Provide adequate parkland and other open space;

• E. Lessen traffic congestion through the creation of alternative routes and reduce traffic speeds in residential settings.

Technical standards for subdivision improvements and infrastructure are found in Division VI, Subdivisions. (Ord. 2003-02 § 3, 2003).

Blocks within proposed subdivisions shall be designed in compliance with the following standards, except where different requirements are established for a particular planning area within the city by Division III, Project Design.

A. Street Layout. Streets within new subdivisions shall align with and connect to those of adjacent subdivisions, avoiding the tendency for the proposed subdivision to become an enclave apart from the rest of the community. Public streets should be planned to be continuous through adjacent residential developments, where permitted by terrain and other natural features, to weave the community together and simplify traffic circulation patterns. Requirements for street widths and other street cross-section features are established by Chapter 19.12 SMC, Streetscape, and by Division III, Project Design, for the planning area applicable to the site.

B. Cul-de-Sac Streets. The use of cul-de-sac streets is strongly discouraged, except where the location or configuration of the parcel to be subdivided will not permit a through street to be used, or a significant natural or cultural feature can be more effectively preserved through the use of a cul-de-sac. Where a cul-de-sac street is approved, the review authority shall require pedestrian connections from the cul-de-sac bulb to the next adjacent through street wherever feasible. The length of a cul-de-sac street shall not exceed 500 feet.

The Sonoma Municipal Code is current through Ordinance 13-2025, passed December 3, 2025.

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Title 19 Integrated Development Regulations and Guidelines | Sonoma Municipal Code

C. Block Length. The block dimension between intersecting public streets should normally not exceed 300 feet, or be less than 200 feet.

D. Edge Blocks. Subdivisions proposed on sites with significant natural features (for example, creeks) shall be designed to provide a single-loaded “frontage road” adjacent to the natural feature, rather than “backing-up” development to the feature. Proposed subdivisions that are located adjacent to the city’s corporate boundary should also be designed to provide the single-loaded frontage road at the edge. See Figure 2-2, below.

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E. Alleys. The use of alleys is encouraged in new subdivisions, in order to provide access to second units and parking and loading facilities and to improve the pedestrian orientation of primary streets by reducing or eliminating curb cuts. Suggested locations for the inclusion of alleys in future subdivisions and other developments may be established by Division III, within particular planning areas.

F. Gated Neighborhoods. Gated residential developments isolate parts of the community from others, and are strongly discouraged.

G. Natural Features. Creeks, existing healthy mature trees, and other obvious natural features existing on a site proposed for subdivision, should be preserved and incorporated into the project and its landscaping elements to the greatest extent feasible. Additional requirements are established by SMC 19.40.050, Hillside development, SMC 19.40.060, Landscape standards, and Chapter 12.08 SMC, Tree Ordinance.

H. Parks and Neighborhood Open Space. Residential subdivisions shall provide dedicated parkland or park in-lieu fees as provided in SMC 16.10.030, Parkland dedications and fees.

The Sonoma Municipal Code is current through Ordinance 13-2025, passed December 3, 2025.

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Title 19 Integrated Development Regulations and Guidelines | Sonoma Municipal Code

1. Guidelines for Park Development. The planning commission shall make use of the following guidelines in its review of any development within which dedicated parkland is proposed:

   • a. Such facilities should be centrally located within the development and should be located at street frontages rather than behind lot lines (although alternative locations may be considered in order to take advantage of significant natural features).

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• b. Where feasible, significant natural features should be incorporated into parks.

• c. Residential subdivisions should be designed to integrate and connect with proposed park and other open space elements (for example, creek corridors) and with existing and proposed trails and pedestrian ways in the site vicinity. (Ord. 2003-02 § 3, 2003).

This section establishes standards and guidelines for the size, location, design and other characteristics of neighborhood commercial development that may be allowed in the R-S (Residential – Sonoma) zone.

A. Development Standards. The following standards shall be applied to any neighborhood commercial center proposed in the RS zone:

The Sonoma Municipal Code is current through Ordinance 13-2025, passed December 3, 2025.

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Title 19 Integrated Development Regulations and Guidelines | Sonoma Municipal Code

1. Neighborhood commercial centers shall be allowed only in conjunction with new developments of 30 units or more.

2. The land area devoted to a neighborhood commercial center shall be confined to a single, defined area, that shall not exceed five percent of the total land area of the development.

3. Uses within neighborhood commercial centers shall be limited to those set forth in Table 2-1, Residential Uses and Permit Requirements, for the R-S zone.

• B. Guidelines. The planning commission shall make use of the following guidelines in its review of any neighborhood commercial center proposed in the RS zone:

  1. Neighborhood commercial centers should be centrally located and should be easily accessible within the development to pedestrians and bicyclists.

  2. Neighborhood commercial centers should incorporate public uses, such as parks.

  3. Higher density residential development should be located within or adjacent to any neighborhood commercial center. (Ord. 2003-02 § 3, 2003).

Proposed subdivisions shall be designed to provide parcels that comply with the minimum area and dimensional requirements of this section, as set forth in Table 2-5, General Lot Size Requirements, unless otherwise specified in the lot size requirements for individual planning areas provided in Division III, Project Design. Variances to the minimum lot size standards set forth in this section shall be governed by SMC 16.02.050, Exceptions to subdivision standards. (Ord. 2003-02 § 3, 2003).

Table 2-5. General Lot Size Requirements[1 ]

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Zoning Minimum Minimum Minimum
District Lot Area Lot Width Lot Depth
R-HS 10 acres 100 feet 100 feet
R-R 0.5 acres 75 feet 100 feet
R-S 5,000 square feet N.A. [2 ]
R-L 8,500 square feet 65 feet 90 feet
75 feet corner lots
R-M 5,000 square feet 55 feet 90 feet
70 feet corner lots
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The Sonoma Municipal Code is current through Ordinance 13-2025, passed December 3, 2025.

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Title 19 Integrated Development Regulations and Guidelines | Sonoma Municipal Code

Table 2-5. General Lot Size Requirements[1 ]

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Zoning Minimum Minimum Minimum
District Lot Area Lot Width Lot Depth
R-H 4,500 square feet 50 feet 90 feet
70 feet corner lots
R-O 4,500 square feet 50 feet 90 feet
70 feet corner lots
MX Commercial: 40 feet N.A.
10,000 square feet
C 40 feet
Residential:
C-G 5,000 square feet 60 feet
W 10 acres 100 feet 100 feet
A 20 acres 100 feet 100 feet
P Minimum lot area determined by the planning commission through the subdivision
review process.
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Notes:

1. Lot size requirements do not apply to condominiums and may be modified through the planned development permit process (SMC 19.54.070).

2. Variations in lot size and width are required in new development. The minimum lot size and width shall be determined by the planning commission in the course of development review of individual projects.