Chapter 18.03


18.03.010    Purpose.

18.03.020    General provisions.

18.03.030    Fractions.

18.03.040    Measuring distances.

18.03.050    Measuring height.

18.03.060    Measuring lot width and depth.

18.03.070    Determining average slope.

18.03.080    Determining floor area.

18.03.090    Determining floor area ratio.

18.03.100    Determining lot coverage.

18.03.110    Determining lot frontage.

18.03.120    Determining setbacks (yards).

18.03.130    Measuring signs.

18.03.140    Measuring parking lot landscaping.

18.03.150    Measuring pedestrian clearance.

18.03.010 Purpose.

The purpose of this chapter is to explain how various measurements referred to in this title are to be calculated. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.020 General provisions.

For all calculations, the applicant shall be responsible for supplying drawings illustrating the measurements that apply to a project. These drawings shall be drawn to scale and of sufficient detail to allow easy verification upon inspection by the Director. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.030 Fractions.

Whenever this title requires consideration of distances, parking spaces, dwelling units or other aspects of development or the physical environment expressed in numerical quantities, and the result of a calculation contains a fraction of a whole number, the results will be rounded as follows:

A.    General Rounding. Fractions of one-half or greater shall be rounded up to the nearest whole number and fractions of less than one-half shall be rounded down to the nearest whole number, except as otherwise provided.

B.    Exception for State Affordable Housing Density Bonus. The calculation of fractions related to permitted bonus density units for projects eligible for bonus density pursuant to Government Code Section 65915 or any successor statute, and Chapters 18.16, Affordable Housing Programs, and 18.17, Affordable Housing Incentives, is described in Chapters 18.16, Affordable Housing Programs, and 18.17, Affordable Housing Incentives. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.040 Measuring distances.

A.    Measurements Are Shortest Distance. When measuring a required distance, such as the minimum distance between a structure and a lot line, the measurement is made at the closest or shortest distance between the two objects.

B.    Distances Are Measured Horizontally. When determining distances for setbacks and structure dimensions, all distances are measured along a horizontal plane from the appropriate line, edge of building, structure, storage area, parking area, or other object. These distances are not measured by following the topography or slope of the land.

C.    Measurements Involving a Structure. Measurements involving a structure are made to the closest support element of the structure. Structures or portions of structures that are entirely underground are not included in measuring required distances.

D.    Measurement of Vehicle Stacking or Travel Areas. Measurement of a minimum travel distance for vehicles, such as garage entrance setbacks and stacking lane distances, is measured down the center of the vehicle travel area. For example, curving driveways and travel lanes are measured along the center arc of the driveway or traffic lane.

E.    Measuring Radius. When a specified land use is required to be located a minimum distance from another land use, the minimum distance is measured in a straight line from all points along the lot line of the subject project, in all directions.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.050 Measuring height.

A.    Measuring Building Height. Building height is the vertical distance measured in feet between the “ground” level and the highest point of the structure directly above, the roof beams of a flat roof, the deck line of a mansard roof or the highest peak or gable of a pitched or hipped roof. For purposes of this rule, the “ground” level is the lowest of the following three levels: the curb level, the established or mean street grade if no curb exists, or the finished ground level adjoining the building if the building is set back more than ten feet from the street right-of-way.


1.    Measuring Building Height on Sloped Lots. On lots with a grade change of ten percent or more between the front and rear lot lines, or the most distant point from the front lot line when there is no rear lot line, building height is measured from the adjacent grade, natural or finished, whichever is lower, at the highest point of the structure directly above.


2.    Exceptions. Antennas, belfries, chimneys, cooling towers, cupolas, domes, elevator bulkheads, flagpoles, ornamental towers, penthouses, solar collectors, spires and standpipes and necessary mechanical equipment may exceed the height limits pursuant to Section 18.15.060, Height and height exceptions.

B.    Measuring the Number of Stories in a Building. In measuring the height of a building in stories, the following measurement rules shall apply:

1.    A balcony or mezzanine shall be counted as a full story if its floor area exceeds one-third of the total area of the nearest full floor directly below it or if it is enclosed on more than two sides.

2.    A basement shall be counted as a full story if the finished surface of the floor above the basement is:

a.    More than six feet above grade plane; or

b.    More than twelve feet above the finished ground level at any point.


3.    A story shall not exceed twenty-five feet in height from the upper surface of the floor to the ceiling above.

C.    Measuring Height of Fences or Walls. The height of any fence or wall shall be determined by measuring the vertical distance from the highest existing grade at a point within a three-foot radius of any point on such fence or structure to the highest point of such structure. In the case of fences or walls between the setback line and lot line, height shall be measured from highest finished grade adjacent to the structure to the top of the structure as determined by the Director.

1.    Measuring Height of Fences on Retaining Walls. The height of a fence that is on top of a retaining wall is measured from the highest existing grade point within a three-foot radius of any point on such fence to the highest point of the fence on the highest side of the wall. Any fence or railing required to comply with minimum height in applicable Building Code requirements is permitted.


D.    Measuring the Height of Decks. Deck height is determined by measuring from the ground to the top of the floor of the deck directly above the ground below.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.060 Measuring lot width and depth.

A.    Lot Width. Lot width is the horizontal distance between the side lot lines, measured at right angles to the lot depth at a point midway between the front and rear lot lines.

B.    Lot Depth. Lot depth is measured along a straight line drawn from the midpoint of the front property line of the lot to the midpoint of the rear property line or to the most distant point on any other lot line where there is no rear lot line.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.070 Determining average slope.

The average slope of a parcel is calculated using the following formula: S = 100(I)(L)/A, where:

A.    S = Average slope (in percent);

B.    I = Contour interval (in feet);

C.    L = Total length of all contour lines on the parcel (in feet);

D.    A = Area of subject parcel (in square feet). (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.080 Determining floor area.

The floor area of a building is the sum of the gross horizontal areas of all floors of a building or other enclosed structure, measured from the outside perimeter of the exterior walls and/or the centerline of interior walls.

A.    Included in Floor Area. Floor area includes, but is not limited to, all habitable space (as defined in the California Building Code) that is below the roof and within the outer surface of the main walls of principal or accessory buildings or the centerlines of party walls separating such buildings or portions thereof or within lines drawn parallel to and two feet within the roof line of any building without walls. Garages in the RS-6 zoning district shall be included in floor area calculations. In the case of a multi-story building that has covered or enclosed stairways, stairwells or elevator shafts, the horizontal area of such features shall be counted only once at the floor level of their greatest area of horizontal extent.

B.    Excluded from Floor Area. Floor area does not include mechanical, electrical, and communication equipment rooms that do not exceed two percent of the building’s gross floor area; bay windows or other architectural projections where the vertical distance between the lowest surface of the projection and the finished floor is thirty inches or greater; areas that qualify as usable open space; and in nonresidential buildings, areas used for off-street parking spaces or loading spaces, driveways, ramps between floors of a multi-level parking garage, and maneuvering aisles that are located below the finish grade of the property.

In addition, in the RS-6 zoning district the following shall be excluded from floor area calculations:

1.    Basements that are located directly beneath the house footprint (with exceptions for lightwells and access to areas underground) and with an exposed area of no more than three feet from finished grade to finished floor above.

2.    Up to four hundred fifty square feet of garage area, provided the garage is detached and located to the rear of residential structures, and is a minimum of forty feet away from the front lot line.

C.    Nonresidential Uses. For nonresidential uses, gross floor area includes pedestrian access interior walkways or corridors, interior courtyards, walkways, paseos, or corridors covered by a roof or skylight. Nonresidential gross floor area does not include arcades, porticoes, and similar open areas that are located at or near street level and are accessible to the general public but are not designed or used as sales, display, storage, service, or production areas. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.090 Determining floor area ratio.

The floor area ratio (FAR) is the ratio of the floor area, excluding the areas described below, of all principal and accessory buildings on a site to the site area. To calculate the FAR, floor area is divided by site area, and typically expressed as a decimal. For example, if the floor area of all buildings on a site totals twenty thousand square feet, and the site area is ten thousand square feet, the FAR is expressed as 2.0.

A.    Excluded from Floor Area in Calculating FAR.

1.    Underground Areas. Floor area located below finished grade.

2.    Parking. Parking areas located below finished grade or finished floor of habitable space where the vertical distance between finished grade and finished floor is five feet or less. Structured parking areas located above finished grade or finished floor of habitable space where the vertical distance between finished grade of finished floor is more than five feet are included as floor area in calculating FAR.

3.    Sideloaded or Detached Garages. Sideloaded or detached garages not exceeding four hundred fifty square feet, located to the rear of residential structures, a minimum of forty feet away from the front lot line and accessed by a driveway the entire length of which is less than twelve feet in width.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1480 (Exh. A), 2015: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.100 Determining lot coverage.

Lot coverage is the ratio of the total footprint area of all structures on a lot to the net lot area, typically expressed as a percentage. The footprints of all principal and accessory structures, including garages, carports, covered patios, and roofed porches, shall be summed in order to calculate lot coverage. The following structures shall be excluded from the calculation:

A.    Unenclosed and unroofed decks, uncovered patio slab, porches, landings, balconies and stairways less than eighteen inches in height at surface of deck (and less than six feet including railings);

B.    Eaves and roof overhangs projecting up to two feet from a wall;

C.    Trellises and similar structures that have roofs that are at least fifty percent open to the sky with uniformly distributed openings;

D.    Swimming pools and hot tubs that are not enclosed in roofed structures or decks; and

E.    One small, nonhabitable accessory structure under one hundred twenty square feet. Structures above quantity of one shall be included in lot coverage.

F.    In the RS-6 zoning district and not subject to the Hillside overlay district:

1.    Unenclosed and unroofed decks that are greater than eighteen inches in height at surface of deck and where the surface of the deck is equal to or lower than the lowest living level above grade, up to two hundred fifty square feet shall be excluded from lot coverage.

2.    Covered porches in the front yard area that are greater than eighteen inches in height at surface of porch, and where the porch floor surface is at or below the level of the front door, up to two hundred square feet shall be excluded from lot coverage calculations.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.110 Determining lot frontage.

A.    Corner Lot. The front of a lot is the narrowest dimension of the lot with street frontage.

B.    Through Lot. The front yard of a through lot abuts the street that neighboring lots use to provide primary access. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.120 Determining setbacks (yards).

A setback line defining a required yard is parallel to and at the specified distance from the corresponding front, side, or rear property line. The following special regulations for determining yards apply when a lot abuts a proposed street or alley.

A.    Yards Abutting Planned Street Expansions. If a property abuts an existing or proposed street for which the existing right-of-way is narrower than the right-of-way ultimately required for the street, the required setback shall be established from the future right-of-way rather than the property line.

B.    Yards on Alleys.

1.    If a side lot line abuts an alley, the yard shall be considered an interior side yard rather than a corner side yard.

2.    In computing the minimum yard for any lot where such yard abuts an alley, no part of the width of the alley may be considered as part of the required yard.

C.    Measuring Setbacks. Setbacks shall be measured as the distance between the nearest lot line and the closest point on the exterior of a building or structure along a line at right angles to the lot line. Setbacks shall be unobstructed from the ground to the sky except where allowed pursuant to Section 18.15.080, Projections into yards, subject to compliance with the California Building Code.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.130 Measuring signs.

The calculations of measurements related to signs are described in Chapter 18.22, Signs. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.140 Measuring parking lot landscaping.

For the purpose of calculating required parking lot landscaping, parking lot areas are deemed to include parking and loading spaces as well as aisles, vehicle entry and exit areas, and any adjacent paved areas. Parking lot area does not include enclosed vehicle storage areas. (Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)

18.03.150 Measuring pedestrian clearance.

The minimum distance shall be measured from the edge of any table, chair, bench, planter, or other appurtenance used as part of an outdoor dining area to any obstruction within the sidewalk area.


(Ord. 1537 (Exh. A (part)), 2018: Ord. 1438 § 4 (Exh. A (part)), 2011)