This chapter provides general site planning and development standards for all uses that are allowed by district regulations in multiple zoning districts.

(Ord. 4934 § 3 (part), 2007)

   The regulations established in this chapter shall apply to all zoning districts, in addition to other applicable provisions including the standards of the zone district where the use is located.

(Ord. 4934 § 3 (part), 2007)

   Distances between buildings, or between any structure and any property line, setback line, or other line or location prescribed by this title shall be measured to the nearest vertical support or wall of such structure. Where one or more buildings do not have vertical exterior walls, the distances between the buildings shall be prescribed by the building official.

(Ord. 5373 § 20 (part), 2016; Ord. 4934 § 3 (part), 2007)

   (a)   Minimum Distance Required

   The minimum distance between separate buildings located on the same site shall be as required by Title 16; provided, however, accessory buildings in the RE single-family residence districts shall be separated from the principal building by at least three feet.

   (b)   Connection of Principal and Accessory Building

   A principal building and an accessory building, meeting the requirements of Title 16 and each located on a site as otherwise permitted for principal building and accessory buildings, may be connected by a structure meeting the definition of a breezeway. Such structure, or breezeway, shall be a part of the accessory building.

(Ord. 4934 § 3 (part), 2007)

   (a)   Accessory Buildings Setbacks

   Except as otherwise provided in this section, accessory buildings shall at all times be located in conformance with requirements for principal buildings, and shall not be located in any required front, side or rear yard.

   (b)   Limitations of Uses for Accessory Buildings

   In residential zones, accessory buildings may be located in a required interior yard subject to the following limitations:

      (1)   An accessory building shall not be used for living and/or sleeping purposes unless the building was legally constructed for or legally converted to living and/or sleeping purposes prior to October 13, 1983.

      (2)   An accessory building shall not be located in a required front yard, a required street yard, or a required rear yard of a through lot.

      (3)   An accessory building shall not be located in a required interior side or rear yard unless the building is at least seventy-five feet from any street line, measured along the respective lot line.

      (4)   Accessory buildings located within a required interior yard as permitted by this section shall be subject to a maximum height established by a daylight plane beginning at a height of eight feet at the property line and increasing at a slope of three feet for each ten feet of distance from the property line, to a maximum height of twelve feet.

      (5)   No accessory building shall have more than two plumbing fixtures. Accessory buildings shall not be allowed to be turned into habitable space nor shall these structures be allowed to have showers (indoor or outdoor), gas lines, washer/dryers, and/or cooking facilities to be provided inside or attached to the structure, unless the structure is proposed as an ADU/JADU that satisfies all requirements of the Palo Alto Municipal Code.

   (c)   Swimming Pool, Hot Tub and Spa

      No swimming pool, hot tub, spa or similar accessory facility shall be located in any portion of a required front or street side yard.

(Ord. 5585 § 6, 2023: Ord. 4934 § 3 (part), 2007)

   Except as otherwise prescribed by district regulations or other provisions of this title, use and development of required yards shall be limited to the following:

   (a)   Fences, screening, and enclosures permitted by Chapter 16.24;

   (b)   Landscaping;

   (c)   Outdoor recreation, including open structures and ground level facilities related thereto, such as tennis courts, swimming pools, other game or court facilities, sitting areas, decks, patios, terraces, and like features constructed at ground level or within one foot above natural grade; provided, that no below-grade improvements such as swimming pools shall be permitted within three feet from the property line;

   (d)   Pedestrian walkways and driveways;

   (e)   Required parking, in accord with the location provisions specified within each district.

   (a)   Architectural Features

   Cornices, eaves, fireplaces and similar architectural features, excluding flat or continuous walls or enclosures of usable interior space, may extend into a required side yard a distance not exceeding two feet, or may extend into a required front or rear yard a distance not exceeding four feet. Window surfaces, such as bay windows or greenhouse windows, may extend into a required front, side or rear yard a distance not exceeding two feet or into a required front yard a distance not exceeding three feet. In residential districts or nonresidential districts adjacent to residential districts, the window surface may not extend into any yard above a first story.

   (b)   Canopies and Patio Covers

   A canopy or patio cover may be located in any residential district in the required rear yard or that portion of the interior side yard which is more than seventy-five feet from the street lot line measured along the common lot line. Such canopies shall be subject to the following conditions: The permit may be granted by the director without a requirement for public hearing and notice.

      (1)   A canopy or patio cover shall not be more than twelve feet in height.

      (2)   The canopy or patio cover shall be included in the computation of building coverage.

      (3)   The canopy or patio cover and other structures shall not occupy more than fifty percent of the required rear yard.

      (4)   The canopy or patio cover shall not be enclosed on more than two sides.

   (c)   Storage Structures

   Structures not over six feet in height or twenty-five square feet in floor area, used exclusively for storage purposes, may extend into a required side yard a distance not exceeding two feet, or may extend into a required front or rear yard a distance not exceeding four feet.

   (d)   Porches, Stairways, Landings and Fire Escapes

   Uncovered porches, stairways, landings, balconies or fire escapes may extend not more than six feet into a required front or rear yard, and may extend not more than three feet into a required side yard; provided that, in residential districts or in nonresidential districts adjacent to residential districts, these projections may not extend into any yard above a first story.

   (e)   Pools, Spas and Hot Tubs

   Pools, spas and hot tubs may extend into a required rear yard a distance not to exceed fourteen feet, provided that a minimum setback of six feet from the property line shall be maintained.

   (f)   Building Extensions and Corner Lots

   In residential districts, a portion of a main building which is less than half the maximum width of such building may extend into the required rear yard no more than six feet and with a height of no more than one story, except that a corner lot having a common rear property line with an adjoining corner lot may extend into the required rear yard not more than ten feet and with a height of no more than one story.

   (g)   Encroachment into a Special Setback

   Subsections (a) through (d) of this section notwithstanding, a projection shall not be permitted to encroach into a special setback, as established by the setback map pursuant to Chapter 20.08 of the Palo Alto Municipal Code.

   (h)   Excavated Features: Terraces and Terraced Landscaping

   In residential districts the terraced and landscaped portions of excavated features, such as below grade patios and sunken gardens, that comply with the provisions of Sections 18.10.090(c) or 18.12.090(c), as applicable, may extend into a required side yard a distance not to exceed two feet, or may extend into a required rear yard a distance not to exceed four feet.

(Ord. 5373 § 20 (part), 2016; Ord. 4934 § 3 (part), 2007)

   (a)   Specified Provisions and Dates of Recorded Title

   Any lot having a site area, width, or depth less than required by this title, which meets one of the provisions specified in this subsection, may be used as a lot or site under the provisions of this title, subject to the applicable district regulations and other provisions of this title:

      (1)   A lot shown upon an official subdivision map duly approved and recorded;

      (2)   A lot for which a deed or a valid contract of sale is on record in the office of the county recorder of Santa Clara County prior to February 19, 1951, and was of legal area at the time it was recorded;

      (3)   A lot for which individual water, sewer, and/or gas service or services were installed by the city prior to October 8, 1947;

      (4)   A lot upon which a dwelling was constructed on or after October 8, 1947, and prior to July 20, 1978 which at the time of construction complied with all lot width and area requirements;

      (5)   A lot otherwise meeting applicable requirements at the time such lot was created, but which does not meet the minimum requirements of this title as currently applicable to such lot, by reason of annexation, a change in zoning district, or a change in applicable regulations within a district.

   (b)   Substandard Lots Cannot Be Further Reduced

   A substandard lot meeting one of the provisions designated in subsection (a) shall be considered a legal lot; provided the particular measurement (area, width, or depth) not in accord with this title shall not be further reduced.

   (c)   Lots merged by Amendments to Subdivision Map Act

   All lots that were merged by the 1977 amendments to the Subdivision Map Act prior to the adoption of Chapter 234, Statutes 1977, are hereby deemed unmerged.

(Ord. 4934 § 3 (part), 2007)

   Except in OS, RE, R-1, and R-2 districts, flues, chimneys, exhaust fans or air conditioning equipment, elevator equipment, cooling towers, antennas, and similar architectural, utility, or mechanical features may exceed the height limit established in any district by not more than fifteen feet; provided, however, that no such feature or structure in excess of the height limit shall be used for habitable space, or for any commercial or advertising purposes. In OS, RE, R-1, and R-2 districts, flues, chimneys and antennas may exceed the established height limit by not more than fifteen feet.

(Ord. 4934 § 3 (part), 2007)

(Ord. 4934 § 3 (part), 2007)

   No structures other than fences or landscaping features shall be located within any portion of an easement granted to the city for utility purposes, unless authorized pursuant to an encroachment permit granted by the city. Any structure now existing which does not comply with this section shall not be expanded, enlarged, or replaced in event of demolition or destruction, except as may be authorized by an encroachment permit issued by the city.

(Ord. 4934 § 3 (part), 2007)

   In any area within the city identified by the Comprehensive Plan as having moderate or high risk due to flood hazard, seismic activity hazard, to other geologic hazard, the following provisions shall apply:

   (a)   Geologic Report - High Risk

   In areas identified as subject to high risk, the building official may require, prior to issuance of a building permit or other permit authorizing any new construction, submission by the permit applicant of detailed geologic, soils, and engineering data sufficient to define the extent of any potential hazard and to demonstrate that the proposed construction shall, to the maximum extent feasible, mitigate or otherwise recognize such hazard. Such reports and data shall be required for any use involving public assembly.

   (b)   Geologic Report - Moderate Risk

   In areas identified as subject to moderate risk, the building official may require such reports as described in (a) for any use except single-family use or two-family use. Such reports and data shall be required for any use involving public assembly.

(Ord. 4934 § 3 (part), 2007)

   (a)   Purpose

   The purpose of this section is to encourage creative and sustainable landscape design that enhances structures, open space areas, streetscapes and parking areas. Sustainable landscape design preserves native plant species to the maximum extent feasible, consumes less water and provides permeable surfaces for storm water management and groundwater recharge. Tree shading and appropriate landscape design can contribute to economic vitality and public health, and can reduce the need for frequent infrastructure repair. Landscaping provides recreation areas, cleans the air and water, prevents erosion, offers fire protection, replaces ecosystems displaced by development, and is water efficient.

   In addition to the provisions of this section, all projects shall adhere to the landscape requirements cited elsewhere in Title 18 (Zoning Ordinance), including but not limited to:

      (1)   Design Standards - General Parking Facilities (Section 18.54.020).

      (2)   Design Standards - Landscaping in Parking Facilities and Required Landscape Areas (Section 18.54.040).

      (3)   Architectural Review Findings (Section 18.76.020).

   (c)   Natural Areas (Open Space District, Hillside Lands, Baylands, Creek and Riparian Areas)

   Landscaping should retain or enhance native vegetation in hillside, baylands or other natural open spaces areas or adjacent to such areas. The existing natural vegetation and land formations should remain in a natural state unless modification is found to be necessary or appropriate for a specific use allowed through architectural or site design review.

      (1)   In the selection of new landscaping, preference shall be given to natural, indigenous and drought resistant plants and materials. Non-indigenous landscaping should be limited to the immediate area around a structure or structures.

      (2)   Site development plans shall, to the maximum extent feasible, provide for the retention of existing vegetation and land formations, and shall include an erosion and sediment control element setting forth reasonable mitigation measures in accord with the grading and subdivision ordinances of the city.

      (3)   Landscaping shall, to the maximum extent feasible, integrate and accommodate existing trees and vegetation to be preserved; make use of water-conserving plants, materials and irrigation systems; and be clustered in natural appearing groups, as opposed to being placed in rows or regularly spaced.

      (4)   Colors of roofing materials shall blend with the natural landscape and be nonreflective. All roof mounted equipment shall be screened in a manner that protects the viewshed from adjacent properties, including from views from above.

      (5)   Planting of invasive plant species shall not be permitted and removal of invasive species may be required as part of landscape plan requirements.

      (6)   To the maximum extent feasible, existing vegetation shall be retained or enhanced to maintain contiguous wildlife habitat.

      (7)   Riparian vegetation shall be retained or enhanced within natural stream corridors, and best practices for development shall be used to protect riparian habitat and water quality of adjacent streams.

      (1)   In the R-1, R-2, and RMD zones, a minimum of 50% of the required front setback area shall be landscaped, subject to the limitations of Section 18.12.040(h). Planting in the right-of-way shall not count towards fulfillment of the required landscape area.

      (2)   Street trees may be required to be planted in the right-of-way frontage of any residential structure subject to individual review for a new second story or addition to a second story, or for other discretionary review in the R-1, R-2, or RMD zones.

      (3)   Trees planted near public bicycle trails or curbs shall be of a species and installed in a manner that prevents physical damage to sidewalks, curbs, gutters and other public improvements.

      (4)   Trees and shrubs shall be planted so that at maturity they do not interfere with service lines (a minimum of five feet from water lines and ten feet from sanitary sewer lines) and traffic safety visibility areas.

      (5)   All proposed light wells and below-grade basements shall be screened to minimize visibility from public rights-of-way or other public properties.

   (e)   Special Design and Landscaping Standards for All Zoning Districts Requirements:

   The purpose of the water resources protection measures specified below is to provide site planning and development standards designed to preserve riparian resources, protect improvements from damage caused by potential stream flooding and bank erosion, and minimize storm water pollution. The further intent of the regulations and guidelines is to consider these factors in site planning early in the review process.

   (b)   Water Resources Protection for Streamside Properties

      (1)   Streamside Review Area Defined

   "Streamside review area" means all properties abutting a stream or located within 50 feet from the top of a stream bank, except those properties separated from the stream by a public street.

      (2)   Applicability of Streamside Review Area Requirements and Guidelines

   For parcels within the streamside review area, the following types of developments are subject to these requirements and guidelines listed in subsections (3) and (4) below.

         (a)   Development in all zones except the R-1, R-2 and RMD districts;

         (b)   Development in the R-1, R-2, or RMD zones requiring discretionary review, including but not limited to:

            (i)   Individual review for a new two-story home

            (ii)   Individual review for a new second story on an existing house, where an expansion or change in the building footprint results

            (iii)   Variances, including for fences

            (iv)   Home Improvement Exceptions; and

         (c)   Development requiring a Conditional Use Permit in the R-1, R-2, or RMD zones.

   The following projects are exempt from streamside review area requirements and guidelines:

         (a)   Less than 3 cubic yards of earthwork associated with landscaping with native riparian vegetation or with remedial creek bank stability work deemed necessary by the director of public works;

         (b)   Interior construction; or

         (c)   Replacement of utility service laterals where location outside the protected areas is not readily available.

      (3)   Requirements Within streamside review area

         (a)   Slope stability protection area. All development shall be located outside the slope stability protection area. The slope stability protection area shall extend to a point 20 feet landward from the top of bank or to a point measured at a ratio of 2:1 (horizontal: vertical) landward from the toe of bank, whichever is greater.

   The following structures/uses shall not be allowed within the slope stability protection area:

            (i)   All structures (including accessory structures);

            (ii)   Decks of any height;

            (iii)   Swimming pools, spas, and hot tubs; and

            (iv)   Parking lots.

   Exceptions to this requirement may be granted by the director of public works where the applicant provides a geotechnical slope stability analysis, demonstrating that the proposed development would not threaten the stability of the stream bank slope, require introduction of hardscape in order to maintain the stream bank slope, or be at risk of damage from future bank stability or erosion, and demonstrating how maintenance and repair of the stream could be provided with the proposed development in place, subject to compliance with requirements (b) through (i) below and with all applicable zoning setbacks.

         (b)   New fences shall be constructed a minimum of five feet landward from the top of bank.

         (c)   All native riparian vegetation within 100 feet from the top of bank shall be retained unless its removal is approved by the director of planning and development services. Replacement planting shall be required when native riparian vegetation is approved for removal.

         (d)   Planting of non-native invasive plant species is not permitted. Prohibited plant material is listed in the Santa Clara Valley Water Resources Protection Collaborative's User Manual Guidelines and Standards for Land Uses Near Streams.

         (e)   Only native riparian vegetation shall be planted between the top of the banks of a stream.

         (f)   Loading docks, trash enclosures, chemical storage areas, and stationary noise-producing mechanical equipment shall be located a minimum of 50 feet from the top of bank of a stream, provided that the director may allow noise-producing equipment closer than 50 feet where site conditions and/or other setback requirements make compliance impractical.

         (g)   Nighttime lighting shall be directed away from the riparian corridor of a stream.

         (h)   Irrigation systems shall be designed such that they do not cause soil erosion.

         (i)   All permitted improvements shall be constructed in a manner consistent with the current version of the Santa Clara Valley Water Resources Protection Collaborative User Manual Guidelines and Standards for Land Uses Near Streams.

      (4)   Guidelines Within Streamside Review Area

         (a)   The distance between nighttime lighting and the riparian corridor of a stream should be maximized.

         (b)   Bright colors and glossy or glare-producing building finishes on buildings facing streams or riparian areas should be avoided.

         (c)   Lot Measurement Along Watercourses

   No portion of a lot which is located within the easement lines, or top of the banks in the event such easement lines cannot be ascertained, of any natural watercourse, river, stream, creek, waterway, channel, or flood-control easement or drainage easement shall be included in the determination of lot area and lot dimensions. In the case of any such lot which is bounded, in whole or in part, by any such natural watercourse, river, stream, creek, waterway, channel, or flood-control easement or drainage easement, for those portions of the lot so bounded, all measurements and dimensions specified by this title and related to or determined from lot lines shall be measured from said easement line, or top of the bank, of such watercourse. Provided the expansion of an existing easement over a lot adjacent to San Francisquito Creek and fronting on Edgewood Drive in favor of the Santa Clara Valley Water District (or its successor in interest) on or after January 1, 2002 shall not alter the calculation of lot area. Lot area, lot dimensions, and setbacks shall be calculated for such lots as if the post-January 1, 2002 easement had not been created.

(Ord. 5494 § 3, 2020: Ord. 4934 § 3 (part), 2007)

   (a)   Purpose

   The purpose of this section is to preserve and enhance storm water quality by reducing pollutants discharged to streams and the San Francisco Bay. Projects are encouraged to incorporate site design measures to reduce storm water pollution by decreasing or slowing storm water runoff or interrupting the flow of runoff across a series of contiguous impervious surfaces into land development projects.

   (b)   Applicability of Guidelines

   All projects are subject to these guidelines. The following site design measures should be included in site and building design wherever feasible in order to minimize storm water runoff and protect and enhance the quality of storm water runoff leaving the site.

   (c)   Guidelines for Storm Water Quality Protection

      (1)   Minimize land disturbance and preserve high-quality open space, riparian corridors, and wetlands on the development site.

      (2)   Minimize the amount of impervious surface (e.g., buildings, roads, driveways, parking lots, etc.).

      (3)   Minimize directly connected impervious areas by routing storm runoff into vegetated swales and other landscaped areas before it reaches a storm drain, street, or stream.

      (4)   Utilize minimum-impact street design standards (e.g., narrow streets and sidewalks, permeable pavements, etc.).

      (5)   Utilize minimum-impact parking lot design standards (e.g., parking lot island and perimeter landscaping for storm water drainage, permeable pavements, etc.).

      (6)   Utilize minimum-impact driveway design standards (e.g., narrow width, "Hollywood" strips, shared driveways, permeable pavements, etc.).

      (7)   Cluster structures, pavement and other impervious surfaces on the development site.

      (8)   Route rain water leaders into landscaped areas through the use of splash blocks or pop-up emitters, rather than directly to an underground storm drain, in order to promote filtration and infiltration of roof runoff.

      (9)   Utilize microdetention techniques (e.g., bioretention planters, cisterns, etc.) to slow and reduce storm runoff.

      (10)   Minimize changes to the volume, flow rate, timing, or duration of storm runoff from the development site.

(Ord. 4934 § 3 (part), 2007)

   (a)   Except where necessary for health and safety purposes (as determined by the City’s Building Official), no permit required under Title 2 (Administrative Code), Title 12 (Public Works and Utilities), or Title 16 (Building Regulations) shall be issued:

      (1)   For demolition or deconstruction of a single family residence or duplex in the Low-Density Residential District (Chapter 18.10) or Single Family Residential District (Chapter 18.12), unless building permit plans for a replacement project have been approved. This subsection shall also apply to demolition of a single family residence or duplex in the Multiple Family Residential District (Chapter 18.13) when the replacement project does not require discretionary review.

      (2)   For any project requiring discretionary review under Title 18 or Title 21, unless the application for discretionary review has been approved.

      (3)   For demolition or deconstruction of a residential unit, unless a replacement project has been approved that contains at least as many residential dwelling units as will be demolished.

         (A)   If the proposed development project is not a housing development project, the replacement housing units may be located on a site other than the project site but shall be located within Palo Alto and shall be developed prior to or concurrently with the proposed development project.

         (B)   If the existing residential unit(s) is a nonconforming use, it shall be replaced in a manner consistent with the current zone district regulations.

         (C)   Replacement of protected units, as those terms are defined in California Government Code Section 66300.5, shall be subject to the additional requirements of California Government Code Section 66300.6.

   (b)   Notwithstanding subdivision (a) of this section, a permit for demolition or deconstruction may be issued before the approval of planning entitlements or building permits for a replacement project in order to allow for the remediation of hazardous conditions on the site.

      (1)   This subdivision (b) applies only to properties that are eligible for inclusion on any list of hazardous materials release sites maintained pursuant to California Government Code Section 65962.5 and are subject to a remediation plan or similar that has been approved by the applicable oversight agency, such as the California Department of Toxic Substances Control, California Water Resources Control Board, or County of Santa Clara Department of Environmental Health, and that requires demolition or deconstruction of the existing site improvements for decontamination to proceed.

      (2)   No trees shall be removed unless required under the remediation plan. Any tree removed shall be subject to Title 8 of this code. The Director may defer any tree canopy replacement requirements until construction of the replacement project on the site and require a performance bond or similar security instrument.

      (3)   Sites granted an early demolition or deconstruction permit pursuant to this subdivision (b) must remediate the hazardous site conditions to cleanup levels compatible with residential use, as approved by the applicable environmental oversight agency, such as the California Department of Toxic Substances Control, California Water Resources Control Board, or County of Santa Clara Department of Environmental Health.

      (4)   If the subject property is designated as a housing inventory site in the City’s operative housing element, the site may be used only for a housing development project as defined in California Government Code Section 65589.5. The property owner shall sign and record a covenant against the property, in a form acceptable to the city attorney, which requires that the property be used only as the site of a housing development project for as long as the subject property is listed as a housing inventory site in the operative housing element. The covenant shall be binding upon all successors in interest to the property.

      (5)   This subdivision (b) does not apply if the subject property is listed in, or is determined to be eligible for listing in, the California Register of Historical Resources.

      (6)   This subdivision (b) does not apply if it would require demolition of an existing residential use on a portion of the property in order to complete remediation.

      (7)   This subdivision (b) shall be effective only through March 10, 2026, unless extended by the City Council or superseded by replacement ordinance.

      (8)   Sites granted an early demolition or deconstruction permit pursuant to this subdivision (b) must submit a Site Maintenance Plan and receive approval from the Director of Planning prior to issuance of the demolition or deconstruction permit. The Site Maintenance Plan shall address the proposed condition of the site following the completion of remediation work and until a building permit is issued for a replacement project. The Site Maintenance Plan may include measures such as installation and maintenance of fencing to secure the property as well as landscaping.

(Ord. 5648 § 2, 2025: Ord. 5646 § 6, 2025: Ord. 5587 § 13, 2023: Ord. 5542 § 12, 2022: Ord. 5538 § 12, 2021: Ord. 5406 § 3, 2017)

The director shall have the authority to forward projects to City Council for final action in the circumstances listed below. No action by the Director shall be required, and the appeal process and or request for hearing process shall not apply to such referred actions, provided, however, that the Director may seek a recommendation from the Architectural Review Board or Planning and Transportation Commission prior to action by the City Council.

   (a)   In the case of projects having multiple entitlements, where one requires City Council approval, all entitlements may be referred to City Council for final action;

   (b)   Projects involving leases or agreements for the use of City-owned property; and

   (c)   Projects requiring a statement of overriding considerations, pursuant to Section 18.31.010; and

   (d)   Projects, as deemed appropriate by the director.

(Ord. 5493 § 4, 2020: Ord. 5406 § 4, 2017)

   (a)   Conversion of Retail and Retail-Like Uses Prohibited.

      (1)   Any ground floor Retail or Retail-Like use permitted or operating as of March 2, 2015 may be replaced only by another Retail or Retail-Like use, as permitted in the applicable district.

         (A)   A ground floor Retail or Retail-Like use in the RT-35 district on properties with frontage on Alma Street between Channing Avenue and Lincoln Avenue may additionally be replaced by a Private Educational Facility use, provided that such use shall not be thereafter replaced by an Office use.

      (2)   The phrase 'use permitted or operating' as used in this section means:

         (A)   A lawfully established use conducting business, including legal non-conforming uses.

         (B)   An established use conducting business without required city approvals, but is a permitted or conditionally permitted use in district.

         (C)   For parcels vacant on March 2, 2015, the last use that was lawfully established, or established without required permits, and permitted or conditionally permitted in the district.

   (b)   Non-conforming Uses.

      (1)   The requirements imposed by subsection (a) shall not apply to Retail or Retail-like uses that are no longer permitted or conditionally permitted in the applicable district.

      (2)   Nothing in this section shall modify the provisions of Chapter 18.70 regarding the expansion, change, discontinuance, or termination of a non-conforming use.

   (c)   Waivers and Adjustments; and Exemptions.

      (1)   Grounds. The following shall be grounds for a request for waiver or adjustment of the requirements contained in this section:

         (A)   Economic Hardship. An applicant may request that the requirements of this section be adjusted or waived based on a showing that applying the requirements of this section would effectuate an unconstitutional taking of property or otherwise have an unconstitutional application to the property; or

         (B)   Alternative Viable Active Use. Except in the GF or R combining districts, an applicant may request that the requirements of this Section 18.40.160 be adjusted or waived based on a showing that: the permitted retail or retail-like use is not viable; the proposed use will support the purposes of the zoning district and Comprehensive Plan land use designation; and the proposed use will encourage active pedestrian-oriented activity and connections.

      (2)   Documentation. The applicant shall bear the burden of presenting substantial evidence to support a waiver or modification request under this Section and shall set forth in detail the factual and legal basis for the claim, including all supporting technical documentation. Evidence in support of a waiver under subsection (c)(1)(B) must demonstrate the viability of existing and future uses on the site, based on both the site characteristics and the surrounding uses; specifically whether a substitute use could be designed and/or conditioned to contribute to the goals and purposes of the zoning district. Examples of such evidence include:

         (A)   A 10-year history of the site's occupancy and reasons for respective tenants vacating the site;

         (B)   A map that indicates all the existing surrounding uses, both residential and non-residential, within one City-block; include the corresponding zone district on the map;

      (3)   Any request under this section shall be submitted to the Director together with supporting documentation. The Director, in his or her sole discretion, may act on a request for waiver or refer the matter to the City Council.

         (A)   A decision by the Director shall be placed on the City Council's consent calendar within 45 days.

         (B)   Removal of the recommendation from the consent calendar shall require three votes, and shall result in a new public hearing before the City Council, following which the City Council shall take action on the waiver request.

         (C)   The decision of the Council is final.

      (4)   Exemptions. The following uses shall be exempt or partially exempt from the provisions of this Section 18.40.180, as provided below:

         (A)   A 100% affordable housing project not within the Ground Floor (GF) and/or Retail (R) combining districts nor El Camino Real Node area as depicted in Figure 5. A "100% affordable housing project" as used herein shall have the same meaning as provided in Section 18.14.040(c).

         (B)   A 100% affordable housing project on a site abutting El Camino Real outside the Retail (R) combining district. A "100% affordable housing project" as used herein shall have the same meaning as provided in Section 18.14.040(c).

         (C)   A residential project located on a Housing Element Opportunity Site listed in Appendix D of the Housing Element, except for projects located within an El Camino Real Node area, as depicted in Figure 5, that utilize the Housing Incentive Program to exceed the realistic capacity estimates identified in Appendix D of the Housing Element.

         (D)   A high-density residential or mixed-use project shall be required to replace only up to 1,500 square feet of an existing retail or retail-like use and shall be exempt from minimum vehicle parking requirements pursuant to Chapter 18.52 (Table 1) for this retail or retail-like floor area. For the purposes of this partial exemption, high-density shall mean 30 or more dwelling units per acre. This reduction in retail square footage and minimum vehicle parking requirements shall not apply for a site within the Ground Floor (GF) or Retail (R) combining districts, or within an El Camino Real Retail Node area, unless the site is a Housing Element opportunity site, as depicted in Figure 5.

         (E)   The El Camino Real Node map in Figure 5 may be updated by resolution of the City Council or by administrative regulation issued by the Director of Planning and Development Services.

   (d)   Reconstruction.

      Any ground floor Retail use existing on or after March 2, 2015 may be demolished and rebuilt provided that the portion of square footage used as Retail use on or after March 2, 2015 is not reduced except that Retail square footage may be reduced by the minimum amount needed to provide access to any new upper floor and/or lower level.

   (e)   Applicability to Current Requirements.

      Nothing in this section shall alter requirements of site-specific Planned Community zoning ordinances or adopted conditions of approval. Nothing in the section shall be construed to waive the requirement for a conditional use permit or other entitlement where such requirements currently exist.

(Res. 10274 § 2, 2026: Ord. 5650 § 9, 2025: Ord. 5512 § 5, 2020: Ord. 5460 § 9, 2019: Ord. 5407 § 6, 2017)

   (a)   Applicant Withdrawal.

   The applicant may withdraw any rezoning, permit or other application submitted pursuant to this title at any time before action to approve, conditionally approve or deny the application has been taken by the decision making body, by providing written notification to the director.

   (b)   Inactive Applications.

   Where there is inactivity on an application on the part of the applicant for a period of at least six consecutive months, the director shall have the authority to deem an application withdrawn after providing written notice as provided herein. The director shall provide notice of his or her intent to deem an application withdrawn at least thirty days prior to the proposed effective date. Such notice shall be provided by first class mail to the last known address of the applicant on record with the director. For purposes of this section, “inactivity” on an application means that the director has requested from the applicant or has provided the applicant with notice of additional information, materials and/or fees needed by the director from the applicant to continue to process the application and the applicant has failed to adequately respond to that request or notice.

(Ord. 5432 § 11 (part), 2018)

   The director shall have the authority to require the filing of a new application when a pending application project description, proposed land uses, building design, or other aspects of the project are substantially modified as to warrant a new review of the project to applicable code sections. The filing of a new application shall be subject to new fees and shall render the previous application withdrawn.

(Ord. 5432 § 11 (part), 2018)

   Cap new square feet of office/R&D development citywide at 850,000 square feet, exempting medical office uses in the Stanford University Medical Center (SUMC) vicinity. Use January 1, 2015 as the baseline and monitor development towards the cap on an annual basis. Continue to exempt medical, governmental and institutional uses from the cap on office/R&D development; no other exemptions are allowed.

   Through December 31, 2030, this Section 18.40.220 may not be amended or repealed except by a vote of the people, provided, however, that the Palo Alto City Council may reduce the citywide cap of 850,000 new square feet of office/R&D development without a vote of the people.

(Ord. 5446 § 2, 2018, adopting a citizen initiative)

   Where allowed under this Title, in order to qualify as usable open space, a rooftop garden shall meet the following standards:

   (a)   Permanent fixtures on the rooftop shall be placed so as not to exceed height limit for the applicable zoning district, except:

      (i)   Elevators, stairs and guardrails may exceed the height limit to allow for access to the rooftop useable open space. These fixtures shall be designed to the lowest height and size feasible in order to comply with applicable building codes.

      (ii)   Permanent fixtures associated with the useable open space, such as trellises, shade structures, furniture, and furnishings such as planters, lighting and heaters, may exceed the height limit by up to 12 feet.

      (iii)   For the height limit exceptions in (i) and (ii) above, all fixtures shall not intersect a plane measured at a forty-five degree angle from the edge of the building starting at the rooftop garden surface sloping upward and inward toward the center of the property.

   (b)   The rooftop garden shall be located on the third or higher story.

   (c)   The rooftop garden shall be accessible to all residents of dwelling units on the parcel, but not to commercial tenants of a residential mixed-use development.

   (d)   Structures or fixtures providing a means of access or egress (i.e., stairway, elevator) shall be located away from the building edge to the extent feasible to minimize visibility from the public right-of-way and adjacent buildings and privacy impacts. These access structures or fixtures, when exceeding the height limit, shall be subject to the provisions of subsection (a)(iii) above.

   (e)   For lighting requirements, refer to Section 18.40.250.

   (f)   At least 15% but no more than 25% of the rooftop shall be landscaped with raised beds for gardening, C.3 stormwater planters, or other landscaping. All required landscaped areas shall be equipped with automatic irrigation systems and be properly drained.

   (g)   Rooftop equipment that emit noise and/or exhaust, including but not limited to vents, flues, generators, pumps, air conditioning compressors, and other protrusions through the roof, shall be directed away and screened from the useable open space areas.

   (h)   Rooftop open space noise levels shall not exceed exterior residential noise level as defined by Section 9.10.030(a) of this code.

   (i)   The use of sound amplifying equipment shall be prohibited. Signs shall be affixed adjacent to access elevators and stairs within the rooftop garden providing notice of this prohibition.

(Ord. 5692 § 3, 2026: Ord. 5460 § 10, 2019)

   (a)   Purpose

      Utilities, mechanical equipment, service areas, and other site fixtures should be:

      (1)   Integrated into the site planning and architectural design of a project and surrounding uses.

      (2)   Visually screened from public view and from adjacent properties through architectural design, landscaping and screening devices.

   (b)   Requirements

      (1)   For non-residential properties abutting residential uses:

         (A)   A solid wall or fence between five and eight feet in height shall be constructed and maintained along the residential property line.

         (B)   Walls facing residential properties shall incorporate architectural design features and landscaping in order to reduce apparent mass and bulk.

         (C)   Loading docks and exterior storage of materials or equipment shall be screened from view from residential properties by fencing, walls or landscape buffers.

         (D)   All required interior yards (setbacks) abutting residential properties shall be planted and maintained as a landscaped screen.

      (2)   For all project types:

         (A)   All areas not covered by structures, service yards, walkways, driveways, and parking spaces shall be landscaped with ground cover, shrubs, and/or trees.

         (B)   Rooftop equipment shall be screened by a parapet or enclosure. Rooftop equipment or rooftop equipment enclosures shall be set back at least 20 feet from the building edge or a minimum of 100 feet from the property line, whichever is closer. Roof vents, flues and other protrusions through the roof of any building or structure shall be obscured from ground-level public view (when viewed from the sidewalk on the opposite side of a street), by a roof screen or proper placement. See Section 18.40.090 (height limit exceptions) for further restrictions.

         (C)   A minimum ten-foot planting and screening strip shall be provided adjacent to any façade abutting a low density residential district (R-1, R-2, or RMD) or abutting railroad tracks.

         (D)   All exterior mechanical and other types of equipment, whether installed on the ground or attached to a building roof or walls, shall be obscured from public view, when viewed from the abutting opposite sidewalk, except for residentially used EVSE and energy storage systems and associated bollards.

         (E)   Windows, balconies or similar openings above the first story should be offset so as not to have a direct line-of-sight into the interior living areas of adjacent units within the project or into units on abutting residential property.

   (c)   Guidelines

      (1)   For landscape buffers to provide a visual screen, trees and shrubs in the buffer area shall be installed in a manner that provides maximum visual separation of residential uses from the commercial or industrial use, taking into consideration topography and sight lines from residences.

      (2)   Size and density of plant materials shall be in proportion to the size of planting areas and the mass of the structure.

      (3)   Plant material selection shall take into consideration solar orientation, drought tolerance, maintenance requirements and privacy screening.

      (4)   Plant material species and container sizes shall allow for a mature appearance within five years.

      (5)   Roof vents, flues and other protrusions through the roof of any building or structure should be clustered where feasible and where visual impacts would thereby be minimized.

      (6)   Building elevations facing residential property should not have highly reflective surfaces, such as reflective metal skin and highly reflective glazing. The paint colors should be in subdued hues.

      (7)   Increased setbacks or more restrictive daylight planes may be proposed by the applicant, or recommended by the architectural review board, as mitigation for the visual impacts of massive buildings.

      (8)   Appropriate landscaping should be used to aid in privacy screening.

      (9)   Planting strips and street trees should be included in the project.

      (10)   Textured and permeable paving materials should be used, where feasible, in pedestrian, driveway and parking areas in order to visually reduce paved areas and to allow for retention and/or infiltration of storm water to reduce pollutants in site runoff.

      (11)   Landscaping material associated with screening should have adequate room to grow and be protected from damage by cars and pedestrian traffic.

      (12)   Where rooftops are visible from offsite, they should be treated to minimize aesthetic impacts, including the use of rooftop gardens or other green spaces, where feasible.

(Ord. 5601 § 6, 2023: Ord. 5554 § 21, 2022)

   (a)   Purpose

      The intent of this section is to establish bird-friendly design standards for glass to minimize hazards for birds and to reduce the potential for collisions.

   (b)   Definitions

      The following terms are defined for the purposes of this section:

      (1)   “Bird-sensitive area” means the areas located east of Highway 101 and west of Foothill Expressway.

      (2)   “Bird-friendly treatment” means treatment to glazing that provides visual cues to birds and reduces the likelihood of bird collisions by incorporating one of the following:

            (i)   For patterns using dots or other isolated solid shapes, each dot or shape must be at least a 1/4 inch in diameter and be no more than 2 inches apart in any direction.

            (ii)   For patterns using lines, they must be at least 1/8 inch in width and spaced no more than 2 inches apart.

            (iii)   Frit, ceramic ink, or other marker types must be opaque, permanently adhered, and durable for the life of the glazing, unless an alternative compliance method is chosen as outlined in Section 18.40.280(e).

      (3)   “Bird hazard installations” are defined as visually unbroken, exterior glazing and/or glass panels that are reflective or transparent that provide a clear line of sight through the glazed elements to porches, courtyards, water features, trees, vegetation, landscaping, or the sky on the other side of the glazed element, including, but not limited to: (A) Freestanding features such as transparent awnings, (B) Transparent handrails and guards, (C) Transparent wind break panels, acoustic barriers, bus, weather shelters, other freestanding transparent walls, or see-through building protrusions; (D) Transparent skyways or walkways; (E) Two or more parallel transparent elements with a distance of 30 feet or less between them, when at least one of the parallel panes is 24 square feet or larger; or (F) Two or more transparent elements on opposing sides and within 12 feet of a corner (perpendicular, acute, or obtuse) when at least one of the panes is 24 square feet or larger.

      (4)   “Elevation” means any exterior walls of a building or structure, as seen from a two-dimensional perspective like the front, side, or rear.

      (5)   “Fenestration” means the openings in a building’s façade, such as door, skylights, and windows.

      (6)   “Glazing” means the reflective, transparent or translucent materials that fill openings in a building’s exterior walls. This typically includes glass but can also encompass other materials like plastic or acrylic sheets that allow light transmission.

   (c)   Applicability

      The bird-friendly design requirements apply to any of the following projects, when a permit is otherwise required:

      (1)   All newly constructed structures and buildings;

      (2)   Substantial remodel, as defined in Section 16.14.070 of the Code; or

      (3)   Any new fenestration or new or replacement bird hazard installations.

   (d)   Bird-Friendly Design Requirements

         (A)   All bird hazard installations.

         (B)   All glazing on an elevation of a building or structure that is unbroken and 24 square feet or larger in size.

         (C)   Glazing within 15 feet of a green roof.

      (2)   Residential and the residential portion of mixed-use development.

         (A)   Within the bird-sensitive area, in addition to the requirements of (d)(1), no more than ten percent of an elevation of any structure or building shall be untreated glazing.

         (B)   Outside of the bird-sensitive area, in addition to the requirements of (d)(1), no more than 40 percent of an elevation above 35 feet of any structure or building shall be untreated glazing.

      (3)   Nonresidential and the nonresidential portion of mixed-use development. In addition to the requirements of (d)(1), no more than ten percent of an elevation of any structure or building shall be untreated glazing.

         (A)   Any portions of an elevation under 35 feet may be allowed to use films, decals, or other products approved by the American Bird Conservancy or its equivalent, subject to Director approval.

   (e)   Alternative Compliance

      Property owners or applicants may request an alternative means of compliance with requirements established in Section 18.40.280(d). The alternative shall be recommended in a report by a biologist or ornithologist holding a degree in wildlife biology or a specialization in ornithology, and having experience in bird-friendly building design. The request shall be submitted and reviewed in accordance with the applicable procedures in Chapter 18.77, and is subject to approval by the Director. The proposed alternative compliance shall:

      (1)   Reduce the risk of bird collision to a level equivalent to or less than that which would result from strict compliance with Section 18.40.280(d); and

      (2)   Be consistent with the intent of this section as set forth in Section 18.40.280(a).

   (f)   Lighting

      All projects shall comply with the outdoor lighting requirements pursuant to Section 18.40.250 of the Municipal Code.

   (g)   Exemptions

      The following types of projects shall be exempt from Section 18.40.280(d):

      (1)   Any historic structure located within the City’s Historic Districts or listed on the City’s Historic Inventory or the State or National Historical Registers, except for new additions where treatment conforms to Secretary of Interior Standards for Rehabilitation of Historic Properties.

      (2)   The first floor of commercial uses facing a public street, up to 14 feet in height, within the following districts:

         (A)   Retail Shopping (R) Combining District

         (B)   Pedestrian Shopping (P) Combining District

         (C)   Ground Floor (GF) Combining District

         (D)   North Ventura Coordinated Area Plan Districts

      (3)   100 percent affordable housing projects as defined in Section 18.32.030.

      (4)   Accessory dwelling units and junior accessory dwelling units pursuant to Chapter 18.09.

      (5)   Outside of the bird-sensitive area, any portions of residential structures under 35 feet.

      (6)   Glazing that is necessary for airport safety or navigation in connection with operations at the Palo Alto Municipal Airport.

   (h)   Additional Provisions and Conflict Precedence

      All applicable windows, doors, or other features must comply with the requirements of this section, in addition to the California Building Code, including the fire hazard severity zone regulations in California Green Buildings Standards Code (CALGreen), Fire Code, and applicable state or federal laws. Within the event that the provisions of this section necessarily conflict with the aforementioned codes or state or federal laws, the standards in the applicable state or federal laws and codes shall prevail.

(Ord. 5695 § 2, 2026)