16.060 Single Lot Development.

A. Purpose. To ensure that the development of parcels subject to the requirements of this Chapter is consistent

with the General Plan goals and policies related to hillside development, and is not visually prominent when

viewed from a community “viewing platform”.

B. Applicability. Section 16.060 applies to New Development, as deOned by this chapter, on any parcel located in

the South Hills and West Hills, as deOned by this Chapter.

C. Site Plan and Architectural Review. Planning Commission approval is required for new development in the

South Hills and West Hills.

D. Development Standards. Any parcel subject to this Chapter is also subject to the requirements of the zoning

district in which the parcel is located. Where the requirements of the underlying zoning district conPict with the

requirements of this chapter, the requirements of this Chapter shall control.

1. Building Height. 30 vertical feet from grade to the uppermost point of the roof as calculated below (see

Figures 16.3, 16.4 and 16.5). No point of any structure shall be more than 30’ above the grade directly

beneath that point.

Figure 16.3 Height Limit when Graded for Foundation Only

The Petaluma Implementing Zoning Ordinance is current through Ordinance 2907, passed September 8, 2025.

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Figure 16.4 Height Limit when Graded for Flat Pad

Figure 16.5 Height Limit when Adding Fill

2. Setbacks. As prescribed by the underlying zoning district in Tables 4.6 through 4.9.

E. Exception to Required Setback. An exception to the setback required by the underlying zoning district may be

provided for as follows:

1. Primary Structure. A primary structure may encroach into a required setback for a distance of not more

than one-half of the required setback, subject to approval by the Planning Commission, if it can be found that

the decrease minimizes the impact of hillside development and grading and is consistent with the guidelines

contained in this chapter. If such a reduction is granted, a compensating increase in setback is required in the

opposing setback. For example, a Ove-foot (5’) reduction in a front setback would increase the rear setback by

Ove feet (5’).

The Petaluma Implementing Zoning Ordinance is current through Ordinance 2907, passed September 8, 2025.

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2. Required Covered Parking. Required covered parking may encroach into a required front and/or side yard

setback if the decrease minimizes the impact of hillside development and grading and is consistent with the

guidelines contained in this chapter.

Findings Required.When the Planning Commission approves a reduction in the required setback, Ondings to

support the granting of the exception shall be provided.

F. Additional Setback Required. In order to protect signiOcant natural resources or to reduce visual prominence of

a proposed development, the Planning Commission may require building setback(s) that exceed(s) the required

setback of the underlying zoning district.

G. Exception to Retaining Wall Height (Section 13.050). For projects subject to Section 16.060, a maximum exposed

retaining wall height of Ove feet (5’) may be permitted with Planning Commission approval.

H. Site Design. The following site design guidelines shall be taken into consideration and incorporated into the

design of a hillside lot whenever possible. Conformance with these guidelines will be determined by the Planning

Commission.

1. Development patterns that form visually protruding or steeply cut slopes for roads or lots should be

avoided.

2. Building pads, including spaces leveled for foundations and the grading for driveways and yards, should

be as small as possible.

3. Building construction and related site grading should not signiOcantly disturb any ephemeral or

perennial watercourse on the site.

4. Buildings should be located to take advantage of existing vegetation for screening.

I. Architectural Design. The following architectural design guidelines shall be taken into consideration and

incorporated into the design of a hillside lot whenever possible. Conformance with these guidelines will be

determined by Planning Commission as part of project review.

1. Design buildings to conform to the natural topography and hillside setting of the site; to follow the

contours of the site; and to blend with the existing terrain in order to reduce bulk and mass.

2. Scale structures to Ot the surroundings, and not visually dominate the landscape. The apparent size of

exterior wall surfaces visible from oR site may be minimized through the use of single story elements, split

level foundations, varying setbacks and structure heights, and landscaping, all designed to break up massive

forms.

3. Design buildings to minimize bulk, mass and volume.

4. Bulk and Mass. Bulk and mass should be minimized when developing a hillside parcel. The following

methods may be used to minimize the bulk and mass of a building.

a. Keep building forms simple (see Figures 16.1 and 16.2).

The Petaluma Implementing Zoning Ordinance is current through Ordinance 2907, passed September 8, 2025.

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b. Avoid architectural styles that are inherently viewed as massive and bulky.

c. Utilize grading cuts, rather than Olls, to create building pads.

d. Excavate or use below-grade rooms to reduce eRective bulk. The visual area of the building can be

minimized through a combined use of grading and landscaping techniques. Earth sheltered buildings

and “living roofs” are encouraged.

e. Exposed understory stem walls should not exceed 5’ and should be Onished with visually recessive,

earth-toned materials.

f. Step the building foundation and roofs with the natural slope (see Figures 16.1 and 16.2).

g. Use horizontal and vertical building components to reduce bulk.

h. Avoid two story wall planes.

i. Step back the second story so the diRerence in wall planes is visible from a distance.

j. Vary elevations, such as stepping back second stories, to conform with topography.

k. Avoid overhanging decks, large staircases, and patios formed by retaining walls that make buildings

appear more massive (see Figure 16.3).

l. Avoid use of solid wall railings that add to the mass of the design.

m. Create light and shadow by providing modest overhangs, projections, alcoves, and plane oRsets.

n. Use a combination of siding materials and articulate walls to reduce expansive, continuous planes.

o. Use vaulted ceilings rather than high walls and ceilings to attics above to achieve a feeling of

volume.

5. Colors and Materials. The following methods may be used to reduce the visibility of hillside development:

a. Use subdued and unobtrusive exterior Onish materials and colors for all structures.

b. Minimize the use of rePective material.

c. Earth tones and colors that occur naturally in the Petaluma hills are encouraged.

d. Structures should not call undue attention to themselves when viewed from a public vantage point.

6. Roofs.

a. Break roof forms and rooPines into smaller building components to rePect the irregular forms of

surrounding natural features (see Figures 16.1 and 16.2).

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b. Generally orient the slope of the main roof in the same direction as the natural slope of the terrain

(see Figures 16.1 and 16.2).

c. Avoid large gable ends on downhill elevations.

d. Light colored and rePective rooOng materials are discouraged.

J. Process. As prescribed by Section 24.050 (Site Plan and Architectural Review).

K. Findings. In addition to the considerations for review identiOed in Section 24.050(E) (Standards for Review of

Applications), the following Ondings, where applicable, are also required:

1. The project meets or exceeds the objectives, standards, and guidelines of the Hillside Ordinance.

2. The design, scale, massing, height and siting of development is compatible and complementary with the

character and scale of the surrounding, developed neighborhood.

3. The design and site layout of the hillside project is respective of and protects the natural environment to

the maximum extent feasible.

4. Site grading has been designed to be as minimal as possible to achieve sensitive hillside design, minimize

tree removal and provide safe site access and required parking.

L. Submittal Documents. In addition to the submittal requirements identiOed on the Development Permit

Application Submittal Requirements Matrix the following shall be provided as indicated:

1. Opportunities and Constraints Map/Site Analysis is required for all projects.

2. Visual Analysis as required at the discretion of Planning staR or the decision making authority.

3. Arborist Report and/or Tree Preservation and Protection Plan as required by Section 17.055. (Ord. 2811

§ 4, 2022.)