Portola Valley Municipal Code Ch. 18.36 Uses Permitted in All Districts

The following uses and facilities are permitted as principal uses in all districts, and the provisions of this title shall not prevent the construction, installation, maintenance or operation thereof:

A. Public or private streets serving property in the district in which they are situated and the use of such streets for normal and usual street purposes.

B. When used for public utility purposes, water or gas pipes, mains or conduits, electric distribution lines, communication lines, sewers or sewer mains and minor incidental appurtenances to any of the above. All electric transmission and/or distribution lines and all communication lines and all appurtenances thereto shall conform to the following:

1. All new transmission, distribution and service lines for electricity and communication shall be installed underground.

2. Existing overhead lines and appurtenances thereto may be replaced unless provided for otherwise in subsection B (5) and (6) below, as long as the lines are not enhanced. That is, the lines shall not have additional capacity to serve either the immediate vicinity or more distant areas.

3. All new equipment appurtenant to transmission, distribution and service lines for electricity and communication shall be installed underground; however, pad-mounted transformers may be permitted if the planning commission finds there is no adverse visual effect from the public right-of-way, from a neighboring property or from within the property itself.

4. When any program for improvement of streets is instituted by the town or by any other person having jurisdiction over any street improvements and such improvements require replacement, relocation, construction, reconstruction or alteration of lines, appurtenances thereto or parts thereof, such changes to the electric and communication lines and facilities shall conform to the provisions of this title for new lines and appurtenant equipment.

5. Existing overhead electric service lines which provide service to an individual property may remain until such time as any of the following occur, at which time the lines shall be placed underground: the location of the service box is moved; the route of the overhead wires from the pole to the structure is changed, or the point where the wires attach to the structure is changed; or whenever a service is increased above a total of one hundred ampheres.

6. Existing overhead communication service lines shall be placed underground whenever this title requires that existing overhead electric service lines be placed underground.

7. The undergrounding provisions for cable television transmission, distribution and service lines shall be established in the franchise ordinance adopted by the town.

8. Undergrounding of existing lines and related facilities on an applicant's property and within adjacent street rights-of-way, utility easements or other public property may be required in connection with zoning amendments, conditional use permits and variances.

9. The provisions of subsection B 1, 3, 4, 5, 6 and 8 hereof shall not apply in those cases wherein the planning commission determines that underground installation is not feasible or practicable and that there is no reasonable alternative location or design for the installation of underground electric or communication lines or appurtenances thereto. The planning commission may establish policies for the administration of this paragraph. Any person aggrieved by the decision of the planning commission may appeal from the decision to the town council.

(Ord. 1990-256 § 2 (Exh. B) (part), 1990; Ord. 1967-80 § 1 (6300), 1967)

When a conditional use permit is granted therefor as provided in Chapter 18.72, the following uses and facilities are permitted in all districts as conditional uses:

A. Major operating facilities of public utilities and other major utility installations when operating requirements necessitate a specific location in order to serve best the immediate vicinity or the town as a whole;

B. Signs as permitted and regulated by Chapter 18.40;

C. The designation and development of buildings and sites determined to be of historical significance by the planning commission so as to render such buildings and sites available for public enjoyment;

D. Wireless communications facilities that serve primarily the town and its sphere of influence and that conform to the provisions of Chapter 18.41 of this title.

(Ord. 2011-393, § 5, 2011; Ord. 1997-295 § 2, 1997; Ord. 1987-219 § 1, 1987; Ord. 1986-210 § 1, 1986; Ord. 1982-190 § 1, 1982; Ord. 1969-99 § 3 (part), 1969; Ord. 1967-80 § 1 (6301), 1967)

The following uses or facilities are permitted in all districts as temporary uses:

A. A voting place used in connection with a municipal or other public election;

B. Structures and uses incidental to a construction operation, including temporary dwelling units that comply with subsection E. below, on the same or an adjoining parcel provided that such structures and uses are of a temporary nature and do not exist for a period longer than twelve months. Such time periods may be extended for structures and uses other than temporary dwelling units, by action of the Town Council;

C. A festival, exhibit or other similar activity when of a noncommercial nature and sponsored by a group residing in the neighborhood, provided the total duration thereof does not exceed fourteen days;

D. Signs as permitted and regulated by Chapter 18.40.

E. Motor homes and travel trailers designed for human habitation are permitted as temporary dwelling units on residentially zoned parcels, provided each one complies with the following provisions:

1. Has less than three hundred twenty square feet of internal living area and measures less than eight feet in width and forty feet in length.

2. Is occupied by the owners of the principal dwelling who are unable to occupy the principal dwelling while it is being remodeled, because it is not suitable for occupancy.

3. Is connected to a sanitary sewer or an on-site septic system.

4. Is connected to an established power supply. A generator power supply is allowed only in an emergency situation (e.g., power outage during a storm).

5. May be placed in a required setback if the ASCC finds the unit would not impact neighboring properties more than would be the case if it were located in conformance with setbacks and that the location in the setback allows for a more appropriate overall construction staging plan.

6. Shall conform to a time limit set by the ASCC, but in no case more than one year. The ASCC approval shall indicate the anticipated starting date and the termination date. The actual starting date shall commence immediately when the temporary dwelling unit is brought on the site.

7. The applicant shall submit a description of the need for the temporary dwelling unit and how the unit would relate to any use of the principal dwelling during the project. This shall include an explanation of how the temporary dwelling unit could impact the timely completion of the construction project.

8. The applicant shall submit a construction staging plan that shows all aspects of the construction operation including any other temporary facilities such as a construction trailer or office. The plan shall demonstrate that there is adequate space and screening to accommodate the temporary dwelling unit and other normal construction uses and activities without undue burden on the neighborhood.

9. The applicant shall show compliance with the requirements of this section on plans submitted with the building permit for the remodeling project along with supporting information as required by this section. The ASCC shall approve all temporary dwelling units concurrently with approval of the proposed remodel of the principal dwelling. All requirements shall be met prior to issuance of the building permit.

10. The applicant shall post security approved by the town attorney in the amount of ten thousand dollars to guarantee removal of the temporary dwelling unit by the earlier of the termination date or ten days after the building official has approved occupancy of the principal dwelling ("removal date"). Additionally, if the temporary dwelling unit is not removed by the removal date, the applicant shall pay the town a fine of two hundred fifty dollars for each day beyond the removal date.

11. The ASCC shall administer the provisions of this section. Neighbors shall be notified in accordance with Section 18.64.085.

(Ord. 2003-353, §§ 1, 2, 2003; Ord. 1967-80 § 1 (6302), 1967)

A. An accessory use is a related minor use which is either (a) necessary to the operation or enjoyment of a lawful principal use or conditional use, or (b) appropriate, incidental and subordinate to any such use. No use in any district shall be permitted as an accessory use which is not qualified as hereinabove set forth, or which constitutes in effect a conversion of a principal use to one not permitted in that district. This section shall apply to new construction and replacement fixtures. In addition to other uses meeting the qualifications set forth in this section, and subject to the limitations set forth in this title, the following accessory uses are permitted in all districts when located on the same parcel as the principal use:

1. The installation and operation of necessary facilities and equipment in connection with such schools and other institutions as are permitted in the respective district;

2. Recreation, refreshment and service buildings in public parks;

3. Required off-street parking spaces and required off-street loading spaces as regulated by this title;

4. Fences and walls subject to the height and area regulations of this title;

5. Hedges, trees, shrubs and other ornamental planting;

6. Horticulture;

7. Electric and communication service lines provided that all such lines are placed underground except where exempted in accordance with the procedure set forth in subsection B of Section 18.36.010;

8. Outdoor Illumination.

i. Purpose. The purpose of this subsection is to provide clear regulations regarding allowable outdoor lighting. The town's general plan states: "Night lighting visible from the exterior of buildings should be strictly limited to that necessary for security, safety and identification. All night lighting, including signs, should be low intensity and shielded from view from residential areas." This chapter aims to provide regulations for outdoor lighting that will:

a. Permit the use of outdoor lighting that does not exceed the minimum necessary for night-time safety, utility, security, and enjoyment.

b. Minimize adverse offsite impacts of lighting such as light trespass and obtrusive light.

c. Curtail light pollution, reduce skyglow and improve the nighttime environment for astronomy and star gazing in keeping with the dark sky movement.

d. Help protect the natural environment from the adverse effects of night lighting.

e. Conserve energy and resources to the greatest extent possible.

ii. Definitions.

a. Brightness shall be measured in lumens.

b. Dark sky compliant fixture or equivalent shall mean a light fixture from which all light emitted directly or indirectly, is projected below a horizontal plane.

c. Flood lighting shall mean any fixture which lights a large area, as opposed to an individual feature such as a step, path or doorway.

d. Manual switch shall mean any light requiring a physical action to control, whether by hardwires at the property, phone or computer application, or other technology.

e. Motion-sensor shall mean any light control which is trigged by motion.

f. Photo-cell shall mean a light-sensitive control that switches lights on or off depending on the level of outdoor light.

g. Timer shall mean any device which controls the hours or amount of time that a light fixture is illuminated.

iii. Applicability. All outdoor lighting installed after the date of effect of this ordinance shall comply with these requirements. This includes, but is not limited to, new lighting, replacement lighting, or any other lighting whether attached to structures, poles, the earth, or any other location. These regulations are meant to apply only to the visible light spectrum.

a. Exceptions.

1. Lighting for signs shall be regulated by Chapter 18.40, Signs.

2. Holiday lighting, including in trees, for up to sixty total days per calendar year.

iv. Lighting Placement.

a. Exterior doors shall have one fixture each.

b. Garage doors may have one or two fixtures, which shall be limited to a total lumen count of one thousand one hundred twenty-five lumens.

c. Low path, step and wall lights for safety and navigation purposes for pedestrian and other non-vehicular uses.

d. Lighting for exterior patios and dining areas shall be recessed and shielded from off-site visibility.

v. Fixture Type. All outdoor lighting fixtures shall be dark sky compliant or equivalent specifically, they shall include the following elements:

a. Shield directing light downward;

b. Bulb not protruding below horizontal plane at bottom of shield;

c. Light spill limited to the object to be illuminated;

d. Fixtures shall not have ability to swivel or adjust direction, except path lighting, which shall not swivel above a forty-five-degree angle from a vertical line down.

vi. Lighting Control. Lighting controls and technologies shall be implemented to the effect that outdoor lights are on only when needed and never during daylight. Controls shall function with dark sky compliant fixtures. Current technologies include manual switches, photo-cells, timers, and motion sensors. Any combination of these technologies may be used, with the following limitations:

a. Motion-sensor lights shall be triggered only by motion within a property and shall not be activated by motion in adjacent property or rights-of-way.

b. Photo-cells shall be used only to ensure lighting is off during the day, as opposed to on a night.

c. Timers shall be included on all motion-sensor lights to ensure that illumination is limited. Timers shall be used only to turn lights off, not on.

d. Lights shall self-extinguish within two minutes of being illuminated.

vii. Prohibited Lighting. The following lighting types and systems are prohibited from being installed or used:

a. Up-lighting;

b. Lighting for night use of uncovered game courts, including tennis, paddle tennis, basketball, riding rings, and similar outdoor recreation facilities and areas;

c. Aerial lasers and other focused beams;

d. Flood lights or lighting;

e. Searchlights;

f. Lighting with no on/off switch or ability to be controlled;

g. Any permanent or temporary lighting in which any single light source exceeds one thousand one hundred twenty-five lumens.

h. Festoon, cafe, or any other string of exposed blubs.

viii. Lighting Requiring ASCC Approval. The following light fixtures, placements, or types are generally discouraged and require ASCC approval in order to be installed:

a. Lighting for landscaping, trees or structures, including entryway features, pillars and posts;

b. Commercial parking lighting.

9. Septic tanks and drain fields;

10. Antennas designed to receive television or microwave signals transmitted from satellite or terrestrial stations. Antennas with diameters exceeding four feet are subject to review by the architectural and site control commission as provided for by paragraph 6 of subsection A of Section 18.64.010.

11. Tennis courts and paddle tennis courts, provided the sum of the maximum depth of cut and maximum height of fill for such facilities shall not exceed the following:

12. Emergency shelters for up to ten individuals only when located on a parcel with a conditional use for a religious institution, subject to a zoning permit. Emergency shelters shall comply with the following standards:

i. Temporary shelter shall be available to residents for no more than sixty days. Extensions up to a total stay of one hundred eighty days may be permissible if no alternative housing is available.

ii. On-site management shall be provided during the hours of shelter operation.

iii. Emergency shelters may include common space for the exclusive use of the guests, and office and meeting space for the exclusive use of emergency shelter staff.

iv. Each shelter shall have a designated outdoor smoking area that is not visible from the street or from adjacent properties. The outdoor smoking area may be screened by vegetation.

v. On-site parking may be provided as shared parking with the church use. If separate on-site parking is needed, the maximum amount required shall be 0.35 parking spaces per one bed plus one space per staff member on duty when guests are present.

(Ord. 2026-455, § 2 (Exh. A), 2026; Ord. 2021-438, § 1, 2021; Ord. 2019-431, § 2, 2019; Ord. 2018-424, § 1, 2018; Ord. 1991-266 §§ 1 (part), 2, 1992: Ord. 1988-242 § 3 (Exh. B) (part), 1988: Ord. 1987-219 § 2, 1987: Ord. 1979-166 § 17, 1979; Ord. 1976-145 § 2, 1976: Ord. 1967-80 § 1 (6303), 1967)