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Brief History of the City of Palo Alto Zoning Ordinance


Table of Contents

  • Initial Zoning Regulations
  • Zoning Update of February 19, 1951
  • Comprehensive Zoning Update of February 27, 1978
  • Zoning Code Amendments Since 1978
  • 2007 Zoning Code Update

Initial Zoning Regulations  

On April 24, 1922, the City of Palo Alto adopted Ordinance No. 234. This ordinance, Palo Alto’s first zoning ordinance, established Use Districts and a "Use of Property Zone Map". With the notion that different land uses are incompatible and ought to be separated from each other, the City was divided into eight (8) land use classifications. The purpose of dividing the City into districts was for the purpose of regulating and establishing the location of trades and industries, businesses, residential dwellings and the location of buildings designed for specific uses. The development limitations in each particular zone were few. The "zone map" (Exhibit 1) created the following districts:

  1. First Residential District
  2. Second Residential District
  3. Third Residential District
  4. Commercial District
  5. Light Industrial District
  6. Industrial District
  7. Agricultural District
  8. Unrestricted District

Zoning Update of February 19, 1951

On February 19, 1951, The Palo Alto City Council updated the zoning code and adopted Ordinance No. 1324 (Chapter 18 of the Municipal Code), expanding Euclidean zoning principles and further defining the land uses allowed in each zone. The Ordinance divided the City into the following 13 zoning districts.

  • R-E   Residential Estate Districts
  • R-1   Single-Family Residence District
  • R-2   Limited Apartment District
  • R-3   Neighborhood Apartment District
  • R-4   General Apartment District
  • C-1   Neighborhood Business District
  • C-2   Central Business District
  • C-3   General Commercial District
  • M-1   Light Industrial District
  • M-2   General Industrial District
  • L-M   Limited Industrial District
  • P-C   Planned Community District
  • O-A   Open Area District

In addition to the foregoing classes of districts, the following combining districts were established:

  • "-A"   Agricultural District
  • "-B"   Special Building Site District
  • "-D"   Design Control District
  • "-S"   Special Parking District

The ordinance was adopted with the intent of promoting and protecting the public health, safety, peace, morals, comfort, convenience, and the general welfare. The Ordinance established regulations to limit the uses of land, the location and uses of buildings, the height and bulk of buildings, required setbacks, the dimensions and areas of building sites and the external appearance of buildings within certain districts. It also provided for the administration and enforcement of the regulations, and prescribed penalties for violations of the zoning code.

Comprehensive Zoning Update of February 27, 1978 

On November 29, 1976 the City Council adopted a new "Comprehensive Plan" for the development of the City of Palo Alto. Attitudes toward growth, environmental protection, and social responsibility had changed dramatically since the previous Comprehensive Plan prepared in 1963. The new "Comprehensive Plan" had strong zoning implications. Since it had been 27 years since the zoning ordinance had been updated, on May 12, 1976, the City began work on an update to the Zoning Code. Many of the "problems" or major changes to the ordinance were identified from programs stated in the new "Comprehensive Plan, Planning Commission Study Sessions, consultant recommendations, and from problems identified by the staff. Goals for the 1976 update included the development of an "ideal" ordinance that was innovative and included new and experimental ideas. Since Palo Alto was, as of 1978, already largely built-out, the primary objective of the new ordinance was protection of the existing desirable development. There was a belief that specific "problem areas" (such as El Camino) could be handled by thorough analysis and hard decisions, not by new forms of zoning. The objective of simplicity, equal treatment of similarly situated properties, the encouragement of creative design solutions, and the avoidance of cumbersome administration were seen as frequently conflicting. It was determined that they must be balanced to suit the Palo Alto Community.

Single Family (SF) Residential Development Standards

Protection of the City’s single family residential neighborhoods was a prime objective of the 1976 Comprehensive Plan and it was agreed that the new ordinance regulations should not differ substantially from the regulations under which many of the neighborhoods were developed. The changes to the R-1 districts were limited to modifications expected to contribute to the improved maintenance, quality, or preservation of unique characteristics of particular neighborhoods. Among the regulations that were identified to be studied, modified, and added to the new zoning ordinance were:

(a)   Vehicle Parking. (Minimize the front yard area allowable for parking).

(b)   Revision of site coverage and setbacks.

(c)   Consideration of differing coverage and height limits in neighborhoods of predominantly single-story homes. (Eichler designed neighborhoods would require regulations that differ from other neighborhoods).

(d)   Second floor setback requirements.

(e)   Permitted projections into yards. (Regulations were reviewed to encourage flexibility.)

(f)   Garage conversions that reduce or eliminate parking.

(g)   Opportunities for additional housing development on deep lots or flag lots to permit secondary dwelling units or a cottage in areas that are deemed appropriate.

(h)   Review of trailer and recreational vehicle storage.

(i)   Placement of carports or garages on lots in relation to neighboring dwellings.

Multiple Family (MF) Standards

As part of the update, it was determined that the multi-family zones were in need of major revisions-both to development standards and district boundaries. The Comprehensive Plan suggested major boundary changes, particularly for those neighborhoods adjoining downtown. Multi-family densities were restructured to provide a gradation of densities from higher densities adjoining downtown commercial to lower densities in some cases to encourage retention of some of the existing single family homes. Although not all adopted, some of the regulations identified to be studied and or modified were:

(a)   Density would be measured in terms of dwelling units, bedrooms, floor area, and population.

(b)   Height, setback, and coverage requirements scaled to reflect the new density ranges.

(c)   Usable open space requirements related to occupancy characteristics.

(d)   Off-street parking requirements related to building use and occupancy.

(e)   Preservation or rehabilitation of lower density uses in zones permitting higher density.

(f)   Rear lot setback provisions relating to nearby dwellings.

(g)   Relationship to single family dwellings.

Commercial Zones and Development Standards

The intent of the City’s commercial zones was to implement distinctions between commercial designations established by the Comprehensive Plan – neighborhood, regional/community, and service. The existing "C" zones did not adequately reflect these functional distinctions. Neighborhood centers were either in the PC or C-2 zones. The C-2 designation also applied to most of downtown, California Avenue, and the Town and Country Center, while C-3 zoning included Stanford Shopping Center, a few blocks of the downtown, and most of the commercial frontage along El Camino Real. The greater size and diversity of downtown, the need for regulations that recognized its separate retail, office, and service functions, and the need to integrate downtown with adjoining residential areas required a downtown zone with functional subdivisions with provisions to maintain essential retail frontage in the downtown pedestrian shopping district.

It was decided that that carefully tailored use lists and development standards should be prepared for:

(a)   Neighborhood shopping areas

(b)   Downtown

(c)   California Avenue

(d)   Stanford Shopping Center

(e)   El Camino Real

Parking Standards

Refinement of parking standards for commercial use and industrial uses were also updated as part of the new zone provisions. Several considerations were identified:

(a)   Provisions for small car parking for a portion of the required spaces.

(b)   Means to meet increased parking requirements resulting from change of use to one generating more parking demand.

(c)   Improved landscaping and design standards.

(d)   Possibilities of joint parking facilities.

(e)   Provisions for bicycle parking facilities.

Industrial, Research, and Office Park Standards

Industrial and office park zones were revised to more closely reflect the character of development that already had occurred. The Comprehensive Plan contained the following programs calling for changes directly related to minimizing employment gains and auto use:

(a)   Reduction of floor area (FAR) and/or site coverage in industrial districts of currently developed properties either to limit employment gains, or to maintain high quality appearance.

(b)   Reduced parking requirements for employers demonstrating successful alternative transportation programs and the reduction in employee automobile use.

Over the next two years, the City and its Land Use Consultant revised the Zoning Ordinance and it was adopted by the City Council on March 20, 1978.

Zoning Code Amendments Since 1978  

Since March 20, 1978, the Zoning Ordinance (Chapter 18 of the Municipal Code) has been amended many times. While all revisions to the zoning code are potentially significant, most are relatively minor. The following is a brief synopsis of the background and description of some of the more significant changes to the Zoning Ordinance since 1978.

1. Addition of the Two Unit Multiple-Family Residence District (RMD) to the City of Palo Alto Municipal Code.

Ordinance No. 3446

Adopted June 20, 1983. Established the RMD (Two-Unit Multiple-Family Residence District) that would allow a second dwelling unit under the same ownership as the initial dwelling unit on site in areas designated for multiple-family use. The purpose of establishing the zone was to minimize incentives to demolish existing single-family dwellings, maintain neighborhood character, and more significantly, increase the variety of housing opportunities available within the community. The maximum density allowable would be 17 dwelling units per acre.

2. Addition of the Neighborhood Preservation Combining District (NP) to the City of Palo Alto Municipal Code.

Ordinance No. 3447

Adopted June 20, 1983. Intended to maintain the visual and historic character of existing neighborhoods. The combining district was established to encourage the retention of existing single family structures, to foster additions to existing structures in lieu of complete demolitions, and to assure neighborhood compatibility of new structures.

3. Amendment to the Palo Alto Municipal Code temporarily banning the issuance of permits to construct second detached single-family dwellings in the Single Family (R-1) Zone District.

Ordinance No. 3489

On September 12, 1983, in response to a large number of permits being issued for large second detached single-family dwelling units in the R-1 Districts, the City Council passed an ordinance effectively banning all such structures greater than 1,000 square feet for a six month period. There was a concern that the size and placement of detached unit in single-family districts ran counter to the Comprehensive Plan’s policies of maintaining the general low-density character of such neighborhoods. The purpose of the ban was to allow time for Planning Staff to review and make recommendations on the appropriate regulations for second detached single-family dwellings. On November 21, 1983, the Staff presented to the City Council Ordinance No. 3489. The Ordinance made the construction of a second dwelling unit in the R-1 district a Conditional Use. To construct a second dwelling unit, the site are must be 35% larger than the minimum lot size allowed in the R-1 district, must be separated from the main dwelling by a distance of 12 feet, and is limited in size to 900 square feet and 20 feet in height.

4. Addition of the General Manufacturing Combining District (B) to the City of Palo Alto Municipal Code to change uses and site development regulations in the East Bayshore Area.

Ordinance No. 3497

On December 7, 1983, the City Council adopted the General Manufacturing Combining district to modify the regulations of the general manufacturing district in areas that have high employment potential and existing significant traffic congestion. The purpose of the district is to prohibit uses, normally allowed in the general manufacturing district, which could have a high traffic generation potential.

5. Addition of the Commercial Downtown District (CD) to the City of Palo Alto Municipal Code.

Ordinance No. 3696

The Commercial Downtown District was adopted by the City Council on July 14, 1986. It was created as a result of the development activity in Downtown during the 1980’s. The development energized the Downtown area, but caused negative effects on parking and traffic congestion. During the same time, the public was increasingly concerned about the compatibility between large commercial projects and nearby residential uses.

The CD zone district was a comprehensive zoning district created for the downtown business area, accommodating a wide range of commercial uses serving citywide and regional businesses and service needs. The district also was intended to provide for residential uses and neighborhood service needs. The CD district had the following objectives:

a.   Control the rate and size of commercial development.

b.   Preserve and promote ground floor retail uses.

c.   Enhance pedestrian activity.

d.   Create harmonious transitions from the commercial areas to the residential areas.

e.   Preserve historic buildings.

All new nonresidential projects (new construction and expansions) were limited to 25,000 gross square feet of floor area or fifteen thousand (15,000) gross square feet above the existing floor area limits. To enhance compatibility with adjacent residential uses, commercial sites within 150 feet of any residential zone were subject to height restrictions of the most restrictive residential zone.

6. Addition of the Home Improvement Exemption (HIE) to the City of Palo Alto Municipal Code

Ordinance No. 4081

On March 16, 1992, Chapter 18.90 of the Municipal Code "Variances and Conditional Use Permits" was amended in its entirety. Most notably, the review of Home Improvement Exceptions (HIE) were added to the duties of the zoning administrator. Similar to a variance, a HIE allows relief from the strict provisions of the zoning ordinance. Unlike a variance that attempts to relieve unnecessary hardship or unreasonable property loss, a HIE provides relief from the zoning regulations to achieve greater neighborhood character or to maintain an existing design concept.

In addition to codifying the HIE process, the amendment also added "basements" to the Site Development regulations for the R-1, R-2, RMD, and RM-15 Site Development Regulations.

7. Addition of the Ground Floor Combining District (GF) to the City of Palo Alto Municipal Code limiting the uses permitted on the ground floor in the Commercial Downtown District.

Ordinance No. 4098

To preserve the integrity and continued economic success of retail in the commercial downtown district and subdistricts, the City Council on June 15, 1992 adopted the Ground Floor Combining District. The intended purpose of the GF district was to modify the uses allowed in the CD commercial downtown district to permit only retail, eating and drinking and other service-orientated commercial development on the ground floor in the downtown. The following uses are permitted in the GF zone on the ground floor:

a.   Eating and drinking

b.   Hotels

c.   Personal Services

d.   Retail Services

e.   Theaters

f.    Travel Agencies

g.   Lobbies serving non-ground floor uses

8. Addition of the Single-Story Height Combining District (S) regulations to the City of Palo Alto Municipal Code.

Ordinance No. 4101

To minimize the negative streetscape impact the construction of new two-story homes could have on established one-story neighborhoods, the Council, on July 13, 1992, adopted the Single-Story Height Combining District (S) regulations. The purpose of the ordinance was to preserve and maintain single-family living areas of predominately single-story character. The maximum building height in the "S" district is limited to 17 feet and a limit of one habitable floor.

2007 Zoning Code Update 

Since the last zoning code update in 1978, the city had amended the Zoning Ordinance many times to address issues of concern to the community. The code that was used on a daily basis by both the staff and the public is the result of 23 years of sometimes-unrelated amendments and confusing and sometimes contradictory provisions.  On September 11, 2007, the Palo Alto City Council approved the final revisions to the City’s comprehensive update of the Zoning Ordinance, Title 18 of the Municipal Code. The revised ordinance became effective on October 11, 2007. The ordinance includes a new format for the code, with a more extensive use of tables and updated definitions. Also included are context-based design criteria (form-based coding) for multi-family, commercial, mixed use, and pedestrian-transit oriented development.

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Last Updated: December 10, 2007