Chapter 8.166 — S72 DISTRICT (COMBINING DISTRICT, WEST MENLO PARK)

The following regulations shall apply in any single-family residential district with which the “S-72” District is combined.

In the case where a requirement, standard, or provision of this Chapter conflicts with another requirement, standard, or provision in the Zoning Regulations, including this Chapter, the most limiting provision shall take precedence and govern.

(Prior code § 6300.4 Ord. 3319; 04/29/91) (Prior code § 6300.4 Amd. Ord. 3535; 01/25/94)

1. Accessory Building. An accessory building is a detached building whose use is incidental to the use of the main building on the parcel, e.g., a garage, shed, pool house. A detached second dwelling unit is not an accessory building.

2. Building Floor Area. The building floor area is the maximum amount of interior floor area. Building floor area includes: (1) the area of all stories of all buildings and accessory buildings (exceeding 80 sq. ft.) on a building site as measured from the outside face of all exterior perimeter walls; (2) the area of all decks, porches, balconies or other areas covered by a waterproof roof which extends four or more feet from exterior walls; and (3) the area of garages and carports, but excludes uninhabitable attics and uninhabitable sub-grade basements.

Where the first floor ceiling height, as measured at the plate line, exceeds 12 feet (excluding skylight wells) and the roof peak immediately above exceeds 20 feet, that portion of the floor area shall be doubled for the purposes of calculating building floor area.

3. Building Height. The building height is the maximum height of a building measured as the vertical distance from any point on the existing grade to a corresponding point immediately above at the top of the building. Chimneys, pipes, mechanical equipment, antennae, and other common facilities may extend beyond the respective maximum height to a maximum of 36 feet as required for safety or efficient operation.

4. Building Setback. A building setback is the minimum building distance as measured from a specified line parallel from the nearest parcel line. Building setback includes front, side, and rear (first and second story) setbacks.

5. Building Site Coverage Ratio. The building site coverage ratio is the maximum amount of parcel area that may be covered, expressed as a percentage of parcel size. Maximum building site coverage shall include all: (1) buildings, (2) accessory buildings, or (3) structures such as patios, decks, balconies, porches, bridges, and other similar uses which are eighteen (18) inches or more above the ground, except fences/walls.

6. Daylight Plane. A daylight plane defines a three dimensional volume of space in which a building may be constructed. Daylight planes shall be measured as a specified maximum vertical distance from a specified point on existing grade to the topmost point of the wall where it intersects the roof immediately above and then inward at a specified angle until the maximum building height is reached.

7. Daylight Plane Protrusion. A daylight plane protrusion is the portion(s) of the building that protrudes into each daylight plane, e.g., gables, dormers, or other architectural features. Daylight plane protrusions may be continuous or combined, but do not include the space between protrusions, when calculating protrusion length. Protruding chimneys, eaves, skylights, and similar features are not considered protrusions and shall not be included when calculating protrusion length. The maximum height of a daylight plane protrusion shall be measured from existing grade.

l features. Daylight plane protrusions may be continuous or combined, but do not include the space between protrusions, when calculating protrusion length. Protruding chimneys, eaves, skylights, and similar features are not considered protrusions and shall not be included when calculating protrusion length. The maximum height of a daylight plane protrusion shall be measured from existing grade.

8. Existing Grade. The existing grade is the grade level that exists prior to any new grading or construction.

9. Story. A story is a habitable space in a building between the surface of any floor and the surface of the floor or roof immediately above, but not including any attic, or basement or under-floor space that is three (3) feet or less above existing grade.

10. Uninhabitable Attic. An uninhabitable attic is the area located between the ceiling joists and the roof rafters immediately above that may not be inhabited. An uninhabitable attic shall be unfinished and shall meet the following criteria: (1) no wall or ceiling drywall covering, (2) attic area floor joists may only be covered with an unfinished floor surface, (3) access to the area is only from the inside of the building, (4) electricity to the area is limited to that necessary for adequate light and not more than one receptacle outlet, (5) no heating is provided to the area, and (6) no rough or finished plumbing is provided to the area.

11. Uninhabitable Basement. An uninhabitable basement is the area located between the first floor joists and the lower floor at grade level that may not be inhabited. An uninhabitable basement shall meet the following criteria: (1) its ceiling height is no greater than six feet, six inches (6’-6”), (2) its area does not contribute to the visible bulk of the building and is not more than 3 feet above existing grade at any point, (3) its floor area may not be more than 50% of the first floor area, and (4) it shall be unfinished.

12. Upper Building Side Wall Length. The upper building side wall length is the maximum combined front to rear length(s) of a building along a line less than ten (10) feet inward from and parallel to a side setback line, measured at any point 17 feet or more above existing grade. Its rear-most point shall not extend beyond the second-story rear setback line.

The minimum building site width shall be an average of 50 feet.

The minimum building site area shall be 5,000 sq. ft.

The maximum density of development shall be 8.7 dwelling units per net acre.

The minimum setbacks shall be:

Front: 20 feet

Sides: 10 feet - When the side property line fronts a public or private street

5 feet - All other cases

Rear: First Story: 20 feet

Second Story:

Parcel Length Rear Setback 0 - 100 feet 20 feet 101 - 120 feet 40 - (121 - parcel length) >120 feet 40 feet

The maximum building site coverage area ratio shall be .50 (50%).

The maximum building floor area shall be established according to the following table:

Building Site Area Maximum Floor Area ≤5,000 sq. ft. 2,800 sq. ft. >5,000 sq. ft. .26 (building site area - 5,000) + 2,800 sq. ft.

Contiguous parcels may be combined to establish a building site area to be used to calculate the maximum building floor area provided the parcels are merged pursuant to the merger provisions of the County Subdivision Regulations.

A parcel may not be divided if any resultant parcel has a building site area less than the minimum required to maintain conformity with the required building floor area of this district.

Development plans must conform to one of the following three options that regulate building height, daylight plane, and upper building side wall length. Interchanging or mixing elements from the three options is prohibited.

1. Option 1

a. Requirements

• (1) Building Height. Maximum building height shall be 28 feet, not to exceed two stories.

• (2) Daylight Planes

  • (a) 20-foot/45° Daylight Plane. For all portions of the house located within that area regulated by the upper building side wall requirement, a 20-foot/45° daylight plane, beginning at the side setback lines, shall be required. The vertical portion of the daylight plane shall be determined by a wall height not to exceed 20 feet from the existing grade to that point where the wall intersects the roof, and then inward at an angle of 45° until reaching the maximum building height.

Pitched Roof. For that portion of the house regulated by this daylight plane, only hip, gambrel, and gable roofs shall be allowed. No sloped roof shall be less than 20°.

  - (b) 4/10-foot/45° Daylight Plane.  For all portions of the house not regulated by the upper building side wall requirement, a 4/10-foot/45° daylight plane, beginning at the side facing building walls, shall be required as follows:  The vertical portion of the daylight plane shall be determined by the combined heights of:  (1) a maximum of 4 feet of under-floor/crawl space as measured from the existing grade to the top of the floor joist, and (2) a maximum of 10 feet of ceiling space as measured from the floor surface to that point where the wall intersects the roof or ceiling, and then inward at an angle of 45° until reaching the maximum building height. 

• (3) Daylight Plane Protrusions. Daylight plane protrusions are prohibited.

• (4) Upper Building Side Wall Length. The length of each upper building side wall shall not exceed 40 feet.

• b. Illustration. The regulatory limits of Option 1 requirements are illustrated on the diagram entitled: OPTION 1, BUILDING ENVELOPE.

==> picture [500 x 659] intentionally omitted <==

2. Option 2

• a. Requirements

  • (1) Building Height. Maximum building height shall be 28 feet, not to exceed two stories.

(2) Daylight Planes

• (a) 20-foot/45° Daylight Plane. For all portions of the house located within that area regulated by the upper building side wall requirement, a 20-foot/45° daylight plane, facing the front and rear setback lines, shall be required. The vertical portion of the daylight plane shall be determined by a wall height not to exceed 20 feet from the existing grade to that point where the wall intersects the roof, and then inward at an angle of 45° until reaching the maximum building height.

Pitched Roof. For that portion of the house regulated by this daylight plane, only hip, gambrel, and gable roofs shall be allowed. No sloped roof shall be less than 20°.

• (b) 4/10-foot/45° Daylight Plane. For all portions of the house not regulated by the upper building side wall requirement, a 4/10-foot/45° daylight plane, beginning at the side facing building walls, shall be required as follows: The vertical portion of the daylight plane shall be determined by the combined heights of: (1) a maximum of 4 feet of under-floor/crawl space as measured from the existing grade to the top of the floor joist, and (2) a maximum of 10 feet of ceiling space as measured from the floor surface to that point where the wall intersects the roof or ceiling, and then inward at an angle of 45° until reaching the maximum building height.

(3) Daylight Plane Protrusions

  - (a) 20-foot/45° Daylight Plane.  Where the 20-foot/45° daylight plane is required, daylight plane protrusions are allowed but shall not exceed 20 feet in length and 24 feet in height, and shall be no closer than 5 feet from a side setback line. 

  - ° 

  - (b) 4/10 foot/45 Daylight Plane.  Where the 4/10-foot/45° daylight plane is required, daylight plane protrusions are prohibited. 

• (4) Upper Building Side Wall Length. The length of each upper building side wall shall not exceed 35 feet.

• b. Illustration. The regulatory limits of Option 2 requirements are illustrated on the diagram entitled: OPTION 2, BUILDING ENVELOPE.

==> picture [485 x 622] intentionally omitted <==

3. Option 3

==> picture [88 x 9] intentionally omitted <==

----- Start of picture text -----
a. Requirements
----- End of picture text -----

• (1) Building Height. Maximum building height shall be 30 feet, not to exceed two stories.

• (2) 15-foot/45° Daylight Plane. For all portions of the house, a 15-foot/45° daylight plane, beginning at the side setback lines, shall be required. The vertical portion of the daylight plane shall be determined by a wall height not to exceed 15 feet from the existing grade to that point where the wall intersects the roof, and then inward at an angle of 45° until reaching the maximum building height.

• (3) Daylight Plane Protrusions. Daylight plane protrusions are allowed but shall not exceed 20 feet in length and 24 feet in height.

• (4) Floor Area Bonus. An additional 200 sq. ft. floor area bonus shall be granted in excess of the maximum building floor area or the maximum building site coverage ratio, whichever is less.

• b. Illustration. The regulatory limits of Option 3 are illustrated on the diagram entitled: OPTION 3, BUILDING ENVELOPE.

==> picture [448 x 524] intentionally omitted <==

Detached accessory buildings shall be limited to one story, with a maximum 10-foot plate height and 14-foot building height. The area above the horizontal plate shall be accessible only from within the building. Roof dormers are prohibited.

Detached accessory buildings shall be subject to all other provisions of Chapter 8.348, of this Ordinance Code.

A detached second dwelling unit may be constructed above an existing detached accessory building only if the unit maintains the same setback, height, and daylight plane requirements of the main dwelling. A new detached second dwelling unit constructed within an existing detached accessory building shall require a use permit in accordance with Chapter 8.280 of this Ordinance Code.

Second dwelling units shall be subject to all other provisions of Chapter 8.392 and 8.396 of this Ordinance Code.