Chapter 16.18
GENERAL SUBDIVISION DESIGN STANDARDS

Sections:

16.18.010    Purpose and applicability.

16.18.020    General design requirements.

16.18.030    Lot dimensions.

16.18.040    Location of lot lines.

16.18.050    Depth-width relationship.

16.18.060    Flag lots (deep lot subdivision).

16.18.070    Multiple frontages.

16.18.080    Street layout and alternative design standards.

16.18.090    Sample street layouts for alternative consideration.

16.18.100    Access restrictions.

16.18.110    Alleys.

16.18.120    Street names.

16.18.130    Hillside subdivisions.

16.18.140    Location of development.

16.18.150    Agricultural buffers.

16.18.155    Natural resource preservation— Creeks, wetlands and native habitats.

16.18.160    Energy conservation.

16.18.170    Easements for solar access.

16.18.010 Purpose and applicability.

This chapter establishes standards for the design and layout of divisions of land. These standards apply to subdivisions and conditional certificates of compliance in addition to all other applicable requirements of the municipal code. The purpose of the standards is to ensure, through careful site evaluation and design, the creation of new parcels that are compatible with existing neighborhoods, the natural environment, health and safety of city residents, and are consistent with the policies of the general plan and the community design guidelines. Standards for the physical design of streets and associated public improvements can be found in the city engineering standards, a document maintained by the city public works department. Subdivision design principles can be found in Chapter 5.2 of the city’s community design guidelines. (Ord. 1490 § 3 (part), 2006)

16.18.020 General design requirements.

The design of lots shall be based on intended use, topography, natural resources and access requirements. Lots which are impractical for intended uses due to terrain, location of natural features, inadequate access, frontage, or developable area, or other physical limitations will not be approved.

A. Grading. Natural contours shall be preserved in new subdivisions to the greatest extent possible. Pad development prior to design approval of structures shall be prohibited unless directly associated with public improvements and required drainage. Retaining walls greater than three feet in height, 2:1 slopes or other significant landform alterations are strongly discouraged.

B. Access and Neighborhood Connections. Consistent with General Plan Land Use Element Policies 2.1.4, 2.1.5 and 2.2.6, new subdivisions shall be integrated with existing subdivisions. All subdivisions shall have a street and sidewalk pattern that promotes neighborhood and community cohesiveness. There should be continuous sidewalks or paths of adequate width, connecting neighborhoods with each other and with public and commercial services to provide continuous pedestrian paths throughout the city. Where applicable, it may be necessary to provide safe routes to school at locations other than major roadways. Where new subdivisions that are adjacent to open space, public schools, adjacent street systems or other public spaces, adequate pedestrian (or pedestrian and vehicular) access shall be provided from the new subdivision to the public spaces. In some cases, it may be necessary to gain easements through existing private property and such costs shall be the responsibility of the subdivider. (Ord. 1490 § 3 (part), 2006)

16.18.030 Lot dimensions.

Except as otherwise approved as part of a specific plan, planned development zoning, or common interest subdivision, each lot shall have the minimum area and dimensions indicated in Table 3 for the zone in which it is located.

 

Table 3—Minimum Lot Area and Dimensions

Zone

Min. Lot Area (sq. ft.)

Min. Width (feet)

Min. Depth (feet)

Min. Street Frontage (feet)

C/OS

5 acres or more as required by zone

200

200

20

R-1

6,000

50

90

20

R-2

5,000

50

80

20

R-3

5,000

50

80

20

R-4

5,000

50

80

20

O

5,000

50

80

20

PF

6,000

60

90

40

C-N

6,000

60

90

40

C-R

9,000

60

100

40

C-T

9,000

60

100

40

C-C

6,000

60

90

40

C-D

3,000

25

50

15

C-S

9,000

60

100

40

M

9,000

60

100

40

Exceptions:

1. Lots within common interest subdivisions, as defined in Chapter 16.17, may have any size or shape, except in the R-1 zone where subdivisions must meet the lot size and shape standards described in the table above. In the R-1 zone, variable lot sizes may be allowed through planned development zoning, consistent with Chapters 17.50 and 17.62.

2. In residential subdivisions, corner lots shall have a minimum area fifteen percent greater than otherwise required, and shall be ten feet wider than otherwise required.

3. See specific requirements for flag lots in Section 16.18.060.

4. Minimum lot area calculations shall not include the area between creek banks as described in the open space element and zoning regulations.

5. Residential lots sloped sixteen percent or greater must be increased in size to meet minimum density requirements to allow at least one density unit per lot in accordance with zoning regulations, Section 17.16.010.

(Ord. 1490 § 3 (part), 2006)

16.18.040 Location of lot lines.

A. Side lot lines should generally be perpendicular to the street on straight streets, or radial to the street on curved streets, unless another angle would provide better building orientation for solar exposure or more lot area to the south of the likely building site.

B. Lot lines shall be located within appropriate physical locations, such as the top of creek banks, at appropriate topographical changes (top or bottom of slopes, etc.) or at locations which clearly separate existing and proposed land uses. Lot lines shall not be configured to maximize development capacity at the cost of illogical lot patterns.

C. Contiguous with existing zoning boundaries.

D. On corner lots, the lot lines adjacent to streets shall be rounded in accordance with the radius approved at the street intersection to the satisfaction of the city engineer.

E. No lot shall be divided by a taxing district boundary. City, county, school, other district, or other taxing agency boundary lines may not divide a lot. (Ord. 1490 § 3 (part), 2006)

16.18.050 Depth-width relationship.

Lots with a ratio of depth-to-width greater than three shall not be permitted unless there is adequate assurance that a deep lot subdivision (a flag lot subdivision) will not occur or that deep lot subdivision and subsequent development will be accomplished without detriment to adjacent properties. (Ord. 1490 § 3 (part), 2006)

16.18.060 Flag lots (deep lot subdivision).

Flag lots may be approved for subdividing deep lots where development would not be feasible with the installation of a standard street, either alone or in conjunction with neighboring properties, or where justified by topographical conditions. Such subdivisions shall conform to the following:

A. The accessway serving the flag lot(s) shall not be included in the determination of required lot area for any lot.

B. The original lot shall have frontage on a dedicated street of at least the minimum dimensions required by these regulations (Table 3, Section 16.18.030) for the zone in which it is located, separate from the accessway required to rear lots.

C. The accessway (access lot, not driveway width) to the rear shall be at least twenty feet wide for residential and conservation/open space zones, and forty feet wide for commercial zones (except the C-D zone, which is fifteen feet). Driveway width and paving shall be determined by the city parking and driveway standards and is subject to approval of the community development department director based on use, distance, number of parking spaces and/or units served.

D. Accessway driveways greater than three hundred feet in length and driveways for most commercial subdivisions may be required to provide two-way vehicle access and fire truck access and shall provide appropriate turnaround areas for standard vehicles to exit the driveway in a forward motion without performing more than two turning maneuvers.

E. Each lot shall have yards as required by the zoning regulations. A landscape area with sufficient width to plant screening shrubs and trees (minimum of eight feet) shall be reserved between the access driveway (and any required turnaround areas) and existing or proposed residential structures.

F. For each residence served by a flag lot driveway, one additional off-street parking space shall be provided. The parking space may not be within the street yard or in tandem to other required parking spaces.

G. Where surrounding residential development exists on adjacent parcels, new parcels served by flag lots may be declared as “sensitive sites” by the community development department. A sensitive site shall require architectural review to review the proposed development design and protect adjacent properties from overlook, encroachment of solar access, and adequate noise protection and privacy.

H. The lot farthest from the street shall own the accessway in fee. Other lots using the accessway shall have an access easement over it. (Ord. 1490 § 3 (part), 2006)

16.18.070 Multiple frontages.

Single-family residential lots with frontage on more than one street, other than an alley, are discouraged, except for corner lots or where topography makes a single frontage impractical. The city may require the release of access rights on one frontage which shall be noted on the subdivision map. (Ord. 1490 § 3 (part), 2006)

16.18.080 Street layout and alternative design standards.

Street construction specifications, dimensions, and alternative standards can be found in the city’s engineering standards. The city encourages the use of alternative standards in order to reduce construction costs, provide flexibility and minimize right-of-way widths, pavement widths, turnaround dimensions and intersection curb radii. It is also the intent of this code section to maintain safety standards, provide for more pedestrian-friendly street environments, afford appropriate access for bicyclists, and facilitate implementation of the general plan.

The circulation and street pattern of the proposed subdivision shall conform to the circulation element of the general plan, and shall:

A. Logically relate to the existing streets in the area adjoining the proposed subdivision; and

B. Enable access to future land division and use of adjoining undivided property; and

C. Accommodate pedestrians and bicyclists, consistent with the city’s pedestrian plan and the bicycle transportation plan; and

D. Accommodate public transit facilities; and

E. Be designed to meet city engineering standards to the satisfaction of the public works director, with regard to street cross-sections, length, corner radii, intersection offset, turning space, slope, sight triangles, lighting, signalization, etc.

F. In order to implement general plan policy, streets should be designed with the following considerations:

1. Streets shall be no wider than the minimum width needed to accommodate the typical and usual vehicular mix that the street will serve (including necessary fire access).

2. Residential streets may be built at a variety of widths, depending on their function and hierarchy in the street system.

3. The street design shall facilitate the use of alternative transportation modes: riding transit, biking, or walking. Streets should be designed with all users in mind, including bicyclists and pedestrians (nonmotorized travel).

4. If streets are more than two lanes, they should be divided by planted medians to appear more like two one-way streets.

5. Where cul-de-sacs and other dead-end streets hinder connectivity they should be avoided. Short loops and cul-de-sacs are acceptable as long as higher-order streets (arterials, collectors) offer many interconnections and direct routing.

6. All streets, except for alleys and roads in rural areas or adjacent to natural settings such as parks, should have vertical curbs. A vertical curb clearly distinguishes the space allocated for the automobile from the space provided for pedestrians and people in wheelchairs. (Ord. 1490 § 3 (part), 2006)

16.18.090 Sample street layouts for alternative consideration.

The following graphics are intended to serve as alternative scenarios for street layouts. These standards do not represent adopted street standards and the city engineering standards describe specific dimension requirements; however, the following alternatives are encouraged and may be utilized upon approval by the public works director on a case-by-case basis:

(Ord. 1490 § 3 (part), 2006)

16.18.100 Access restrictions.

Dedication of access rights may be required by the city to control access from adjoining property to public streets. Access restrictions shall be clearly shown on the final map. (Ord. 1490 § 3 (part), 2006)

16.18.110 Alleys.

The city may require dedication and improvement of alleys to serve as rear access to parcels in industrial, commercial, and residential subdivisions. (Ord. 1490 § 3 (part), 2006)

16.18.120 Street names.

Streets which are continuations of the existing streets shall have the same names. Streets which are not continuations or which have significantly changed alignments shall have names that do not duplicate or closely resemble any other street names. (Ord. 1490 § 3 (part), 2006)

16.18.130 Hillside subdivisions.

A. Slope-Density Reduction. In sloping terrain, the overall residential density of a subdivision shall be reduced with increasing slope as provided in the zoning regulations, Section 17.16.010. This shall be done by increasing the size of the lots or by designating a sufficient area for permanent open space. On lots sloped sixteen percent or greater, the lot size shall provide the density for at least one unit value according to the zoning regulations, Section 17.16.010, Table 1. As an option, an area equal to the area required to meet the density requirements may be dedicated as open space in order to reduce the minimum lot size. The open space area shall be either dedicated to the city or protected by a perpetual open space agreement at the option of the city.

B. Hillside Lot Configuration. Increasing lot sizes is the preferred approach in areas of uniform topography. In areas of variable topography the preferred approach is to have substantially larger lots or open space use for the steepest areas, drainage swales, rock outcrops, or shallow soils. Approval of the scheme of lot sizes and open areas shall be at the sole discretion of the city. Open space areas to be maintained for density reduction shall not be counted towards fulfillment of parkland requirements, nor shall the city or subdivider be obligated to provide or maintain any recreational facilities in such areas.

C. Hillside Grading. Subdivisions shall be designed to keep grading and terracing of hillsides to an absolute minimum, consistent with hillside protection policies in the land use and open space elements of the general plan.

D. Grading Design. The design and approach to grading on hillside areas shall be consistent with the open space element of the general plan and utilize the following techniques:

1. Keep a low profile and conform to the natural slopes;

2. Minimize grading on individual lots; generally, locate houses close to the street; minimize the grading of visible driveways;

3. Include planting which is compatible with native hillside vegetation and which provides a visual transition from developed to open areas;

4. The grading plan shall ensure that development near or on portions of a hill or mountain do not cause, or make worse, natural hazards (such as erosion, sedimentation, fire, or water quality concerns);

5. Plans shall include erosion and sediment control practices including temporary vegetation sufficient to stabilize disturbed areas;

6. The grading plan shall maintain the character and visual quality of the adjacent hill or mountain resource;

7. Land alterations should be minimized by: keeping cuts and fills to a minimum; limiting grading to the smallest practical area of land; limiting land exposure to the shortest practical amount of time; replanting graded areas to ensure establishment of plant cover before the next rainy season; and creating grading contours that blend with the natural contours on-site or look like contours that would naturally occur. (Ord. 1490 § 3 (part), 2006)

16.18.140 Location of development.

Subdivisions shall be designed so that development:

A. Is prohibited within areas with natural and cultural resources and provides buffers for these areas as identified in the open space element of the general plan.

B. Is appropriately planned around hazardous areas with a high potential for flooding, seismic risks, land instability, air traffic, excessive exposure to electromagnetic fields, and fire.

C. Is prohibited within areas beyond the urban reserve or development limit line. (Ord. 1490 § 3 (part), 2006)

16.18.150 Agricultural buffers.

(Ord. 1490 § 3 (part), 2006)

16.18.155 Natural resource preservation— Creeks, wetlands and native habitats.

Consistent with general plan policy within the city’s land use and open space elements, new public or private developments adjacent to the lake, creeks, and wetlands must respect the natural environment and incorporate the natural features as project amenities. The following guidelines shall be incorporated into all residential and commercial subdivisions:

A. Creeks and their corridors are to be preserved as open space, and creek corridors are to be maintained in essentially a natural state to protect the community’s water quality, wildlife diversity, and aesthetic value.

B. Developments along creeks should include public access across the development site to the creek and along the creek; provided, that wildlife habitat, public safety, and reasonable privacy and security of the development can be maintained.

C. Sensitive habitat, creek corridors and creek setback areas should be protected by preserving such resource areas and associated habitat buffers through easements. Subdivision parcel lines or easements shall be located to optimize resource protection. If the resource area is within a proposed open space parcel or easement, allowed uses and maintenance responsibilities within that parcel or easement should be clearly defined prior to map approval.

(Ord. 1490 § 3 (part), 2006)

16.18.160 Energy conservation.

All subdivisions shall provide opportunities for passive or natural heating and cooling opportunities to each of the proposed lots, where determined by the reviewing body to be feasible, except for condominium conversion of existing structures where no new structures are added. Such opportunities may include, but are not limited to:

A. Siting of structures or building envelopes to take optimum advantage of passive cooling and heating opportunities.

B. Adjusting building setback lines to promote the optimum spacing of structures to create adequate solar access.

C. Orienting the longest dimension of each lot within thirty degrees of south, unless the subdivider demonstrates that for certain lots:

1. The lots are large enough to allow proper building orientation and maximum feasible control of solar exposure by the lot owner, regardless of lot orientation. Properly oriented building envelopes shall be established for lots smaller than one acre;

2. Buildings will be constructed as part of the subdivision project (as in condominium or planned development) and the buildings themselves will be properly oriented with adequate solar exposure;

3. Topography makes variations from the prescribed orientation desirable to reduce grading or tree removal or to take advantage of a setting which favors early morning or late afternoon exposure, or where topographical conditions make solar energy infeasible;

4. The size of the subdivision in relation to surrounding streets and lots precludes desirable lot orientation. (Ord. 1490 § 3 (part), 2006)

16.18.170 Easements for solar access.

A. In order to provide for the maximum feasible use of solar energy within subdivisions, the city may require establishment of easements for some or all of the lots to protect access to sunlight. Such easements shall be established on each parcel for the benefit of neighboring parcels within the subdivision. Such easements will not be required when:

1. A plan for building construction and landscaping is approved in conjunction with the subdivision approval, and the plan will provide an acceptable level of solar exposure, as provided in the energy element of the general plan; or

2. The size and shape of the parcels together with the yard and height restrictions of the zoning regulations will allow subsequent development of each parcel in a way which will not eliminate acceptable solar exposure for neighboring parcels within the subdivision; or

3. The subdivision is a condominium conversion.

B. Where required, solar access easements shall protect solar exposure during the period from ten a.m. to two p.m. Pacific Standard Time on the winter solstice, unless topographical conditions or other overriding design considerations make protection of some other, equivalent time interval more desirable. They shall be recorded concurrent with recordation of the subdivision map.

1. The burdens and benefits of the solar easement shall be transferable and run with the land to subsequent grantees of the original grantor(s) and grantee(s).

2. The description of the easement shall include:

a. A plan and orthographic view of the easement area in relation to lot lines, together with notations on the maximum height of structures or vegetation which may occupy the easement area;

b. A written description specifying the easement as a plane limiting the height of structures or vegetation, such plane beginning at a line clearly defined in relation to ground elevation and lot line location, and extending upward at a specific angle (altitude) in a specific direction (azimuth);

c. The restrictions placed on vegetation, structures or other objects which would impair or obstruct passage of sunlight through the easement; and

d. Any terms or conditions under which the easement may be revised or terminated.

3. The establishment of solar easements is not intended to result in reducing allowable densities or the percentage of a lot which may be occupied by structures under zoning in force at the time the easement is established. (Ord. 1490 § 3 (part), 2006)