19.10.050 Lot area, yard setbacks, and building coverage standards.

Table 19.10.050 of this section sets forth the minimum lot area, minimum yard setbacks, and lot coverage standards for each residential district. The provisions of this section shall establish the minimum lot area and yard and setback standards for each residential zoning district.

(A) Minimum Lot Area. Except as otherwise provided by this chapter, the minimum lot area shall be determined by multiplying the lot width by the lot depth. The lot width shall be the horizontal distance between the side property lines measured at right angles to the depth at a point midway between the front and rear property lines. The lot depth shall be the horizontal distance between the front and rear property lines of a site measured along a line midway between the side property lines.

(1) Flag Lots.

(a) The area of a flag lot's access corridor shall not be included in determining the site area of the lot (see Figure A-2).

(b) The corridor of land which provides access to a street for a flag lot shall have a minimum street frontage of sixteen feet and a minimum width which is less than the required lot width but not less than sixteen feet (see Figure A-2).

(2) Width of Residential Corner Lots. The minimum width of corner lots in a residential district shall be a minimum of ten percent greater than the minimum width for the district specified in Table 19.10.050 of this chapter.

(3) Depth Adjoining State Highway or Railroad. A lot whose rear lot line abuts a state highway or railroad right-of-way shall have a minimum depth that is at least twenty percent greater than the lot depth standard for the applicable zoning district.

(4) Minimum Lot Frontage on a Cul-de-Sac. Unless otherwise approved by the city council in conjunction with the approval of a subdivision map, all lots in the bulb of a cul-de-sac shall have a minimum width or street frontage at the property line of forty feet.

(B) General Yard Provisions. Except as otherwise provided by this chapter and specific district regulations, the provisions of this section apply to the placement of principal structures. The location of accessory buildings, equipment, and uses and the required separation between primary buildings is addressed elsewhere in this chapter.

(1) Point of Measurement. Except as otherwise provided, required yards shall be measured as the minimum horizontal distance from the appropriate front, side, or rear property line or street/alley right-of-way line of the site to a line parallel thereto on the site (see Figure A-1).

(2) Partially-Improved Streets. Where a site abuts a street having only a portion of its required width dedicated or reserved for street purposes, site area and required yards shall be measured from a line drawn on the boundary of the additional width required for street purposes abutting the site.

(3) Irregularly-Shaped Lots. On corner lots, through lots, lots with three or more frontages, flag lots, and irregularly-shaped lots where the provisions of this chapter do not clearly establish the location of yards and lot lines, the community development director shall make such determination, using the provisions of this chapter for guidance.

(C) Projections into Yards. Projections are permitted into yards required for principal buildings as follows, subject to the provisions of the Uniform Building Code:

(1) Eaves and cantilevered roofs may project up to two and one-half feet, provided:

(a) That such eaves or cantilevered roofs are not closer than two and one-half feet to any lot or street line.

(b) That no portions of such eaves or cantilevered roofs are less than eight feet above grade.

(2) Fireplace structures, buttresses, and wing walls may project up to two and one-half feet, provided:

(a) That a minimum five feet is provided on the side yard where front yard access is provided.

(b) That such structures shall not be utilized to provide closets or otherwise increase usable floor area.

(c) That such fireplace structures are not wider than six feet measured in the general direction of the wall of which it is a part (see Figure A-5).

(3) Bay and greenhouse windows may project up to two and one-half feet, provided:

(a) That such windows are not closer than two and one-half feet to any lot or street line.

(b) That there are no vertical supports or members within the required yard.

(4) Uncovered porches, platforms, landings, and decks, including access stairs thereto may project up to three feet into required interior side yards, and up to five feet into required front, rear, and corner side yards, provided:

(a) That such projections shall not be closer than two feet to any lot or street line;

(b) That such projections are open and unenclosed; provided, however, that an openwork railing not to exceed three and one-half feet in height may be installed;

(d) That such projections do not extend above the level of the first floor.

(5) Awnings and canopies may project up to two and one-half feet into required interior side yards and five feet into required front, rear, and corner side yards, provided:

(a) That such awnings or canopies are not closer than two and one-half feet to any lot or street line;

(b) That such awnings or canopies have no vertical support within such yard;

(c) That such awnings or canopies extend only over the windows or doors to be protected, and for not more than one foot on either side thereof.

(6) Covered patios attached to a dwelling unit may project into a required rear yard, provided:

(a) That such patio is not closer than five feet to any lot line;

(b) That such patio shall remain permanently unenclosed on at least two sides. This provision, however, shall not preclude the placement of detachable screens;

(c) A freestanding patio shall be subject to the same requirements as accessory buildings in rear yards as provided by Section 19.10.060.

(7) Rain conductors, downspouts, utility-service risers, shutoff valves, sills, capitals, bases, cornices, and belt courses may project up to one foot into a required yard.

(8) Water heaters, water softeners, and utility meters, including service conduits and pipes, enclosed or unenclosed may project up to two and one-half feet into a required interior side or rear yard, provided that such structures or equipment are not closer than two and one-half feet to any lot line. Gas meters, if enclosed or adequately screened from view by a structure permitted in the yard, may project up to two and one-half feet into a required front or corner side yard.

(9) Wall and window-mounted air conditioners, coolers, and fans may project into any required yard, provided that such equipment is not closer than two and one-half feet to any lot line.

(D) Maximum Building Coverage. The maximum building coverage allowed in each residential district is the percentage of the building site covered by all primary and accessory structures on the site, measured horizontally to the outside face of exterior walls or structural members. Open decks and balconies and open breezeways connecting two buildings are not included in lot coverage.

Table 19.10.050

SCHEDULE OF RESIDENTIAL DISTRICT REGULATIONS

Zoning Districts	RRH	RE	RR-20000	RR-10000	RS-8000	RS-6500	RM	RH
Maximum density	One unit/acre max	One unit/acre max	2 units/acre	4 units/acre	5-6 units/acre	6-7 units/acre	Per General Plan	Per General Plan
Minimum area per lot	20,000 sq. ft.	43,560 sq. ft.	20,000 sq. ft.	10,000 sq. ft.	8,000 sq. ft.	6,500 sq. ft.	20,000 sq. ft.¹	20,000 sq. ft.¹
Minimum width per lot	100 ft.	120 ft.	75 ft.	70 ft.	65 ft.	60 ft.	100 ft.¹	100 ft.¹
Minimum depth per lot	160 ft.	200 ft.	120 ft.	110 ft.	100 ft.	90 ft.	100 ft.¹	100 ft.¹
Minimum setback from Newell Drive	Single story - 300 ft.	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Minimum setback from Newell Drive	Two-story homes - 400 ft.	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Minimum front yard	30 ft.	10% of lot depth	20 ft.	20 ft.	15 ft.	15 ft.	15 ft.	20 ft.
Garage	35 ft.	10% of lot depth	—	—	20 ft.	20 ft.	20 ft.	—
Minimum side yard
First story	15 ft. with no less than 35 ft. between homes on adjoining parcels	10% of lot width	10 ft.	10 ft.	5 ft.	5 ft.	5 ft.	5 ft.
Second story	20 ft.		10 ft.	10 ft.	8 ft.	8 ft.	10 ft.	10 ft.
Street side of corner lot	25 ft.		10 ft.	10 ft.	10 ft.	10 ft.	10 ft.	10 ft.
Minimum rear yard	30 ft.	25% of lot depth	20 ft.	20 ft.	20 ft.	15 ft.	10 ft.	10 ft.
Building envelope	Maximum	N/A	N/A	N/A	N/A	N/A	N/A	N/A
20,000 sq. ft. to 1 acre lots	8,000 sq. ft.	N/A	N/A	N/A	N/A	N/A	N/A	N/A
> 1 acre lots	12,000 sq. ft.
Maximum building coverage	60% of approved building envelope	30%	30%	30%	40%	40%	50%	50%
Maximum number of stories	2	2.5	2.5	2.5	2.5	2.5	3	3
Maximum building height
Main structure	35 ft.	35 ft.	35 ft.	35 ft.	35 ft.	35 ft.	42 ft.	42 ft.
Detached accessory building	15 ft.	20 ft.	15 ft.	15 ft.	15 ft.	15 ft.	15 ft.	15 ft.

(1) Applies only to the new parcels created after the effective date of the zoning code.

(E) Special Development Requirements for the RRH zoning district:

(1) Subdivisions in the RRH Zoning District shall be subject to the following standards:

(a) Residential lots shall vary significantly in size in order to create the openness and variation characteristic of a rural neighborhood. No more than two contiguous lots shall be of the same size. Lot size variations shall be achieved by varying lot area/lot widths. Parcel size variations on contiguous lots of one acre or less shall vary up or down a minimum of twenty-five percent in size. Contiguous lots larger than one acre shall vary up or down in size by ten percent.

(b) The subdivision design shall ensure protection of designated viewsheds from Newell Drive to the highest ridgeline located to the east of the project.

(c) Each residential lot will identify a maximum building height that will enable other homes with sufficient elevation to achieve a view toward the Napa River wetlands. Technical information that enables identification of a maximum building height will include but not be limited to: lot placement within the subdivision, building envelope placement, and grading. The maximum building height will be recorded in the project CC&Rs (Covenants, Codes and Restrictions).

(d) Design guidelines addressing architecture for individual homes shall be prepared and submitted to the city of American Canyon, concurrently with submittal of a tentative subdivision map, master plan or specific plan. The design guidelines must be consistent with the General Plan Land Use Element Design Principles (Policy 1.11.5).

(e) Native landscaping shall be provided in the Newell Drive setback area. The preliminary and final landscape improvement plans for this common area open space shall include clusters of native shrubs and trees to enhance the privacy and soften the visual form of future homes as viewed from public areas such as Newell Drive. Such landscape improvements shall be approved by the city and maintained by the subdivision's homeowner's association.

(f) Streets within the RRH district may make use of a reduced overall paved width of not less than thirty feet, subject to approval of a design exception to be considered concurrently with the approval of a tentative subdivision map.

(2) Residential Building Permit Requirements.

(a) To determine potential impacts to viewsheds and neighboring properties, the applicant shall install story poles to provide a three-dimensional, full-scale, silhouette structure that outlines the location, bulk and mass that a proposed structure will occupy on a site prior to submittal of a building permit for any structure on a residential parcel.

(b) Prior to submittal of a building permit for any structure or group of structures, the applicant shall submit written documentation from the applicable homeowner's association that the application complies with the design guidelines in the recorded CC&Rs.

(c) An active homeowner's association shall be set up to ensure maintenance of private infrastructure and administer enforcement of neighborhood CC&Rs.

(F) Special Development Requirements for the RE Zoning District on Watson Lane and Paoli Loop:

(1) Proposed subdivisions that create additional residential lots within the RE Zoning District on Watson Lane and Paoli Loop shall be subject to review by the Napa Airport Land Use Commission prior to final action by the City of American Canyon.

(2) This Special Development Requirement shall not apply to any of the following situations:

(a) Subdivisions that do not create additional residential lots (i.e.: Lot Line Adjustment).

(b) Properties on Watson Lane or Paoli Loop without RE zoning.

(d) Properties on Watson Lane or Paoli Loop that are not located in Napa Airport Land Use Compatibility Zone "D."