Types of Zoning Codes and Formats: Discussion Paper

Prepared by the City of Palo Alto

Department of Planning and Community Environment

JULY, 2001



A. Introduction    [top]

As the City of Palo Alto updates its Zoning Ordinance, fundamental issues are raised as to the type of zoning code desired, as well as the format and organization of the ordinance. Many of the issues identified as concerns in the Comprehensive Plan and by the public, City officials, development professionals, and staff emphasize the need to:

  • Incorporate extensive graphics and tables into the Ordinance, to create a more readable and understandable code;

  • Evaluate the potential to use a more "design-oriented" approach to regulations, referred to in the Comprehensive Plan as a "form" code;

  • Organize the Ordinance to make it easier to find topics of interest and to provide references to other pertinent regulations and policies;

  • Provide flexibility to allow for design alternatives while recognizing the unique character of each site and the need to protect adjacent properties;

  • Include a process for occasionally interpreting Ordinance provisions in a form accessible to the public; and

  • Allow for ready access to the Zoning Ordinance online.

In reviewing these issues and others, it may be appropriate to consider first the intent of the zoning ordinance and the variety of different zoning approaches available. Part B of this discussion paper provides background information on the history of zoning codes, including the historic and legal basis for zoning codes and trends in the development and use of zoning codes. Part C outlines and evaluates several different types of zoning codes, and provides examples from Palo Alto and other cities. Part D discusses various code format and organization options, including a comparison of formats for zoning codes for ten cities. Finally, Part E reviews Palo Alto's current zoning code (Title 18) in light of the prior discussion and identifies policy and implementation considerations for Palo Alto's update effort.

B. History of Zoning Codes 

Historic and Legal Basis for Zoning Codes

Zoning allows a local government to control and regulate the uses and characteristics of buildings, structures, and land within its boundaries. The authority for zoning is broadly based on a community's police power, allowing for the protection of the public's health, safety, and general welfare. In 1867 San Francisco became one of the first communities in the United States to use its zoning power to protect existing residences from noxious and hazardous types of uses, such as soap making, fat rendering and dead carcass cremation. The physical separation and isolation of these uses was considered to be a reasonable governmental role to protect one allowed use from another otherwise legal activity. This legal separation and isolation of land uses created the foundation for many current zoning practices. Most of the early zoning laws dealt with just a few uses, usually those that were either clearly obnoxious or socially unacceptable.

The New York Zoning Code of 1916, America's first "comprehensive" zoning code, comprised a "tiered" approach to allowing uses, whereby a more restrictive use (e.g., residential) would be permitted in all of the less restrictive zoning districts, such as commercial or industrial. The "residential" zones would be limited to residential uses, however. Similarly, "commercial" and "residential" uses would be allowed in "industrial" zones, but not the reverse. The bottom tier, e.g., "industrial", would not prohibit any uses. Because of this, land uses in most early American zoning codes were not so isolated as they are now, as residences (all types) were commonly permitted anywhere in a city, and business and commerce were permitted in all but residence zones . Many cities, including Palo Alto, still retain remnants of the "tiered" approach to zoning uses.

Los Angeles in 1909 used zoning and land use controls to limit development of large areas of vacant land. Los Angeles created a multitude of different types of zones, providing the framework for the exclusive "single-family" only residence zones and varying types of commercial and industrial zones (e.g., "light," "heavy," "warehousing") that blossomed in the 1920's - zoning largely designed to protect the social sensitivities and land values of the new, affluent, auto-oriented suburbanites . The subsequent impact of automobile ownership further encouraged the isolation of uses and more exclusive zoning patterns.

In 1926, in the landmark case of Village of Euclid, Ohio v. Ambler Realty Company, the U.S. Supreme Court confirmed the constitutionality of zoning. The Court found that providing for "single-family-only" areas would lead to the promotion and protection of home ownership, which they equated with good citizenship. Numerous court decisions since that time have further validated zoning for a wide variety of purposes, such as economic benefits, environmental protection, and aesthetic enhancement. Challenges to zoning ordinances have generally been based on "equal protection" and "due process" provisions of the Constitution. While judicial challenges based on those provisions have occasionally prevailed, courts have otherwise granted broad discretion to local government to design and implement zoning codes specific to support a community's objectives.

Trends in Zoning

The exclusion of uses from zones and their isolation resulted primarily from the prosperity and suburbanization that followed the Second World War. Zoning was used to address many social and environmental concerns by creating physical isolation and segregation of uses and, arguably unintended, of socioeconomic groups. In the 1950's, the creation of distinct zones was in many instances used to legitimize segregation and social isolation at the very time it was being successfully attacked in the courts (Brown v. Board of Education of Topeka, 1954).

In the 1960's, 1970's and 1980's, the strict separation of land uses and, in particular, low density housing (large minimum lot size requirements, minimum floor area requirements, etc.), was the focus of legal challenges that alleged "exclusionary" zoning by affluent communities to preclude multifamily housing developments affordable to lower income households. Again, in most instances a community's rationale for its regulations was upheld by the courts. There were, however, some significant exceptions, including cases brought against Mt. Laurel, New Jersey in 1975 and 1983, which resulted in efforts in that state to require local agencies to provide a "fair share" of affordable housing.

In the 1970's and 1980's, zoning and land use controls were increasingly used to address environmental concerns, such as creek and tree protection, commercial and industrial performance standards, and water quality and flooding protection. Similarly, standards related to community aesthetics became prevalent, including landscaping, design criteria, view protection, historic preservation, and sign controls. These new regulations generally withstood legal challenges when they demonstrated a basis in promoting the public health, safety and welfare. Under modern law, the general welfare has been construed to encompass aesthetics, property values, economic prosperity, community character, limits on growth, and other values.

In the past decade, zoning ordinances have continued to address changing social and economic conditions and needs. Unique uses such as adult entertainment, wireless communications, newsrack placement, live/work uses, and dot com offices have been regulated by updated zoning codes. In addition, the advent of the Internet and televised public meetings have generated an increased focus on online zoning code access and enhanced public participation provisions.

C. Types of Zoning Codes 

There are several types of zoning codes in use today, and combinations thereof. It is sometimes difficult to distinguish between the "types" of codes and their respective "formats" or "techniques", so all will be discussed here to some extent.

Euclidean Zoning Codes

The traditional zoning code most frequently found in communities around the country is the "Euclidean" code, so named because it is derived from the Village of Euclid, Ohio's regulations, reviewed and upheld in the landmark 1926 Supreme Court case. Euclidean zoning is typically based on a system of zoning districts, lists of uses associated with each zoning district, and dimensional standards:

1. Zoning districts specify a category of uses (e.g., single-family residential, multi-family residential, commercial, industrial, etc.) and are applied geographically on the community's zoning map.

2. Allowable uses indicate the range of residential, non-residential, public, or other uses permitted within a zoning district. While certain uses are "permitted" within the zone, others are identified as "accessory" to the permitted uses, and still others may be allowed only as "conditional" uses, requiring a conditional use permit to determine that the use is appropriate for a specific site and applying special conditions to the use.

3. Dimensional standards include criteria that outline the parameters for the creation of lots and the placement of structures on a lot, i.e., the building "envelope." These standards generally include, but are not limited to: minimum lot size, minimum setbacks, and maximum height.

Euclidean zoning is proscriptive, in other words building contrary to the uses and standards outlined in the code is prohibited. Assuming the standards of the code are met, a project would generally be approved. Over time, a number of other development standards have become accepted additions to the basic dimensional standards, including density and floor-area ratios, to attempt to better control the impacts of development.

Most current city zoning codes, including Palo Alto's, are based on the Euclidean model. The primary advantage of the Euclidean approach is its logical presentation of districts, uses, and standards, a form that is widely familiar to professionals, public officials, and the public. The major disadvantages of the Euclidean ordinance are: 1) its lack of flexibility to address the particulars of a site and its surroundings, and 2) that it does not prescribe precisely what is to be done, allowing for considerable uncertainty as to what the development product will look like.

Flexible Zoning

Flexible zoning codes were a response to the failure of traditional zoning to control the intensity of development to maintain a community's character. At its simplest, traditional zoning assumes that all buildings with the same density (residential) or intensity (FAR) on a lot are equal in their impacts on surrounding properties and streets. While flexible codes are structured in much the same way as Euclidean codes, they may incorporate a variety of techniques intended to address site specific or area specific impacts. Any or all of the following elements may be part of a "flexible zoning code":

1. Overlay districts, sometimes called "combining" districts, are often provided to impose additional criteria on properties, such as a single-story height limitation, a flood protection zone, or a pedestrian-oriented district. The district requirements are usually overlaid on a specific geographic area, but can also be "floating zones", applied only to specific properties to impose further restrictions or to allow added flexibility. Typically, the overlay or combining district is noted as a suffix to the underlying use district, such as CD-P for "downtown commercial" with a "pedestrian" overlay.

The City of Mountain View, California's zoning code, as an example, includes overlay districts for areas designated for: a) single and two-story height limitations; b) neighborhood design for specific neighborhoods; c) paying a parking in-lieu fee rather than providing parking on-site; d) "special design" where special design standards would be applied to a project; and e) "Williamson Act" limitations for agricultural preserves.

The primary advantage of overlay and combining districts is to allow the community the flexibility to impose specific requirements for area-specific or site specific needs. The primary disadvantage is that too many districts may result from this approach, and it can be difficult to identify all relevant requirements for a particular site. Overlay and combining districts, however, have now become a relatively standard zoning tool within the overall Euclidean framework of most cities' zoning ordinances.

2. Planned developments, planned unit developments, or "planned community" zones, as exist in Palo Alto's code, are intended to create a process for bending rigid rules in favor of better site design and land use patterns. These zones are frequently applied at the applicant's request, and usually provide extensive flexibility for the applicant and the community to negotiate an appropriate land use and design solution.

Planned development or planned community zones are frequently applied to larger parcels, often in conjunction with specific plans. However, in some communities, including Palo Alto, there is no minimum parcel size for a planned development zone. It is very unusual to find a community today that does not have some sort of planned development provisions in its zoning code, and many cities have dozens (or, in a few cases, even hundreds) of separate PD-zoned sites.

While there is not a standard format or requirements for planned development provisions, they typically include: a) a purpose statement indicating the desire to allow flexibility to create improved design and amenities, often in a mixed use setting; b) principal uses allowed (if uses are to be limited); c) minimum regulations of a base district that may apply, sometimes including a minimum lot size requirement, height, setbacks, and how mixed uses are treated in FAR and density calculations; d) a highly discretionary process, including detailed application procedures, extensive review and public input, and necessary findings for approval; and e) the nature of the final product, taking the form of an approved development plan and/or agreement, and procedures for amendment.

A common element of the discretionary review process for planned developments is findings or objectives to be addressed, indicating that the intent of the Comprehensive Plan and other community goals are met, such as preservation of natural features, provision of public or recreational facilities, affordable housing or mixed use provisions, relationship to surrounding uses, and accommodation of non-auto oriented modes of transportation (these findings are taken from the City of Santa Rosa, CA's ordinance, which also requires a minimum 15-acre site for "planned community" projects - example attached).

The advantages of the planned development zone are that maximum flexibility is provided for innovative design and deviations from the standard requirements, and that the community may negotiate public benefits that would otherwise be unattainable. The negotiation process may also involve all parties in a "win-win" dialogue. The primary disadvantage is that, because the process is highly discretionary, there is considerable uncertainty for the applicant, the city, and neighbors as to what might be allowed on a site. Depending on the outcome, the community may perceive that development standards were "given away" with no sufficient public benefit, or developers may believe that unreasonable "extractions" have been required. There also may be a tendency to use the planned development zone rather than to "fix" the zoning code so that the existing development standards better accommodate the community's goals. A further disadvantage is that, because each zoning creates its own set of standards for a site, monitoring and administration of requirements for the zone becomes complex, as the site essentially becomes its own zoning district. Staff must then retain all of the specific details of allowable uses and standards for that site in perpetuity, as well as for many others if planned development zoning is used extensively.

3. Performance zoning attempts to regulate the impacts of development, rather than to strictly limit "uses." Performance zoning was initially developed to set commercial and industrial standards (e.g., noise, vibration, odor, glare, air pollution, toxics, outdoor storage - example from Ventura, California attached) in the 1950's, but was widely expanded in the 1960's and 1970's to include: impervious cover limitations, building coverage, landscape surface ratio, trip generation, and water/sewer impacts . While performance zoning was intended to minimize discretion in project review, these criteria today more often are used to supplement "use" provisions and dimensional standards, rather than to supplant them. Performance zoning approaches in Fort Collins, Colorado and Hardin County, Kentucky created point systems to evaluate development, but still relied on some highly discretionary criteria, such as "neighborhood compatibility," for approval (Note: Fort Collins' 1997 Zoning Code update abandoned the performance approach). Lexington, Massachusetts provides flexibility to cluster residential subdivisions based on performance criteria ("maximum development based on impact") when compared to standard subdivisions, but still depends on a discretionary review process for approval (example attached). The criteria to be compared include: gross floor area of dwelling units; living area of dwelling units, site coverage of dwelling units, total number of occupants of dwelling units, and vehicular trip generation from dwelling units. Base numbers for each category in a standard subdivision are provided in the code, as is a worksheet. Discretionary criteria for approval then include objectives for provision of open space, siting of dwellings, visual impacts of the development, parking, and non-vehicular access, so that the process becomes more like a "planned development" approach.

The primary advantage of performance zoning is to provide flexibility regarding density and floor area requirements, instead focusing on the impacts of the project. The disadvantages of the performance approach are that: a) impacts are frequently site-specific, so that a set of numbers may not be adequate to address all impacts; b) the requirements can be difficult to implement, since they often involve complex calculations not familiar to those who use the code; and c) performance zoning to replace "use" limitations ignores some of the fundamental reasons to provide for or prohibit uses (such as providing for neighborhood-serving commercial uses or prohibiting liquor stores in a single-family residential area).

As a result, cities have been reluctant to deviate from density and intensity limits and/or a highly discretionary review process to apply a performance zoning approach. Instead, performance zoning in codes today is generally limited to providing special standards for specific uses, such as the nuisance-related criteria for industrial uses, or standards for large-family day care facilities, home occupations, etc., to minimize discretion in the review of some of these uses.

4. Incentive zoning was developed initially in the 1950's and 1960's to encourage desired development through incentives, again allowing for greater flexibility for the applicant and discretion for the community. The initial applications of incentive zoning occurred in Chicago and New York City, and allowed for increased height and/or reduced setbacks in exchange for public amenities such as plazas or streetscape improvements. Density and other bonuses were initiated in the late 1970's and early 1980's in New Jersey and California, respectively, to encourage affordable housing construction.

Density and floor-area ratio (FAR) bonuses, fee waivers, expedited review, and reduced parking are now relatively common incentive techniques in zoning. The incentives are usually intended to further the community's goals for affordable housing, historic preservation, environmental protection, ground floor retail use, and transit-oriented development.

At least 10 states have now enacted enabling legislation for zoning bonuses and other incentives in exchange for certain public benefits. Generally, however, these statutes do not prescribe directly what types of urban design amenities or bonuses are then acceptable. One exception is statutes dealing with density bonuses for affordable housing, which are usually much more prescriptive (e.g., in California, a 25% density bonus is required for projects providing a minimum of 20% of the units that meet "affordability" criteria).

Examples of incentive zoning include: a) exemption of child care facilities from FAR as part of commercial and industrial developments, in order to encourage child care facilities (City of South San Francisco, CA); b) FAR bonuses for highly sensitive development in scenic corridors (Austin, TX); and c) provision of 40% density and FAR bonuses for a project that includes at least 20% of its housing units as "affordable" (Town of Yountville, CA). Similar affordable housing bonuses are frequently included in the zoning regulations for California cities, primarily because they are required as part of State housing legislation.

The primary advantage of incentive zoning is that it encourages certain objectives of the community without requiring them on a site-specific basis. This often allows flexibility for the applicant to make the incentive provisions work more readily than if they were required. The major disadvantage of "incentive zoning" is that the incentives may never be used, if they aren't truly significant benefits to the applicant. Conversely, if the incentives are too easily realized, the community may be granting excessive development intensity as a trade-off. In some of the earliest applications of incentive zoning in the larger cities, it was eventually determined that the bonus allowed (height) was considerable in contrast to the minor benefits (plazas, public art) provided. As a result, the community's objectives were not met and the ordinances were eventually repealed or revised.

Density bonuses for affordable housing are often a good example of problematic incentives. Some developers may profit more from building at lower densities, resulting in larger homes, than taking advantage of the density bonus. The few bonus units may result in lot and unit sizes on the remaining market rate units being reduced and selling for less. As a result, communities today often require minimum affordable housing levels ("inclusionary zoning") but then provide a bonus for additional affordable units too. There is a delicate balance between what a community requires versus the use of incentives to encourage certain types of development, as well as trying to match the appropriate level of the incentive to the bonus.

Design-Oriented Codes

Design-oriented codes (called "form codes" in the Palo Alto Comprehensive Plan) are frequently referred to as "New Urbanist" codes, as they derive from New Urbanist principles of neo-traditional development, and have received considerable attention in new zoning codes beginning in the 1980's. The principles of "New Urbanism" generally include: more traditional design integrated with the street and public spaces; narrower streets; a wider variety of housing types; mixed-use development to minimize the need for automobiles and to encourage transit use; development of town centers to provide for civic uses and commercial services; commercial structures to the sidewalk and oriented toward the street; provision of open space and linkages to residential and commercial uses; and a strong pedestrian orientation.

The design-oriented codes emphasize specifics of design for product typologies (houses, rowhouses, apartments, shopfront, town center, etc.), including public spaces such as streetscapes and public plazas. This approach minimizes the need for extensive text, and is "prescriptive" in that it prescribes build-to lines (instead of setbacks), placement of garages on sites, façade treatments, and design and planting of street right-of-ways, etc. It may in some instances obviate the need to restrict "uses" in the code, as they are outlined in the accompanying plan or so long as the appropriate design is followed.

Communities that have used "design-oriented" codes have either taken the approach of creating an entirely new code (usually a new or rapidly growing town) or have incorporated elements of the approach into or parallel with existing Euclidean-based codes, creating a "hybrid" code. Some of the primary types and features of design-oriented codes include:

a) Traditional neighborhood development (TND), generally for new residential subdivisions, and including a neighborhood center, open space, and local-serving mixed use development. Design typologies specified may include build-to lines (in lieu of setbacks), orienting garages away from the street; business frontages, and public spaces, especially the streetscape. TND has most generally been applied to newly urbanizing areas, and may be used as a required zoning district or may apply at the applicant's option, as an overlay or a rezoning.

The cities of Jacksonville, Florida and Austin, Texas, have TND districts in their zoning and/or subdivision regulations. In both cities, use of the district provisions is optional and requires a minimum 40-acre site. Some of the key features of the districts include provision of a mix of uses, natural areas, and overall density limitations. A mix of uses is specified (minimum and maximum percentages), and some criteria are provided regarding buffering between uses. A town center, recreation and civic uses are required, as are pathway linkages between uses. Design standards (in text) are required for a number of the typologies, such as "public use," "shopfront use," "town center use," "rowhouse use," and "house use." Interestingly, neither city's TND code contains any graphics.

The cities of Cornelius and Huntersville, North Carolina (suburbs of Charlotte) have also adopted TND provisions as part of codes that are heavily design-oriented. These regulations (examples attached) provide fairly short text summaries of TND regulations, along with graphic representations of desired site layouts and building typologies (TND in each requires minimum 80-acre sites). Both communities are rapidly growing towns of about 30,000 people.

b) Urban villages, which usually include a broader mix of uses and higher intensity than the TND subdivision. Again, typical design elements of building types and public spaces are prescribed. Urban village zones may be applied to newly urbanizing areas or to urban infill areas, particularly when accompanied by a specific (or "regulating") plan.

Cornelius and Huntersville, North Carolina include mixed-use zones within their design-oriented codes, which may be useful for urban village or infill development, as well as in their rapidly growing areas. St. Paul, Minnesota is preparing "urban village" zoning, using the "New Urbanist" principles in a built-out setting. The city's proposal would provide for three districts (replacing about 6 existing zones): 1) TND-1 would apply in transitional areas adjacent to residential and could include a mix of residential, office, and service uses; 2) TND-2 would be a general mixed-use district at pedestrian and transit nodes; and 3) TND-3 would apply to large redevelopment sites (minimum of 10 acres), with extensive TND-type provisions for each project. Some elements of the "New Urbanist" principles, such as the town center or commercial services, could be provided by the existing adjacent development in the built-out setting. These zones would be required, rather than optional or overlay zones. Fort Collins, Colorado's Land Use Code includes design-oriented code provisions for mixed-use development, and extensive design standards incorporated into the Code (example attached).

c) Transit-oriented development (T-O-D) zones, intended for very specific areas adjacent to transit stations or facilities. The T-O-D zone provides for an intense mix of uses, usually including high density residential (and affordable housing). It may be applied to newly urbanizing areas or urban infill adjacent to transit.

As noted, the design-oriented codes usually are applied to newly urbanizing areas or to infill areas where a "Regulating Plan" is developed. The "Regulating Plan" is similar to a specific plan that also outlines the design parameters of building form and the public realm (streets, plazas, town center) within the area. The code is then developed to implement the regulating plan. Design-oriented codes have been used most extensively with the development of new communities (Seaside, Celebration) in Florida, and rapidly urbanizing areas. However, there are also efforts to use design-oriented zoning concepts for redeveloping urban infill sites (such as in Montgomery County, MD and St. Paul, MN), using a "hybrid" approach with a traditional code. Recent publicized efforts in Hercules, California to prepare a design-oriented code (see attached articles) are intended to create a city center for the community on abandoned industrial lands. The proposal includes a "Regulating Plan" for those areas and an accompanying code document. A similar plan and code approach was applied to the downtown area in Oxnard, CA in the mid-1990's.

The primary advantage of the design-oriented codes is that they are "prescriptive", outlining specifically what is expected of new design in an area, and are likely to be better understood by the public, decision makers, and project professionals. The disadvantage of the design-oriented approach is that it is generally applicable to newly urbanizing areas and large redevelopment sites, and therefore may be of limited usefulness for built-out cities. It also requires a considerable front-end effort to prepare a "regulating plan" (much like a "specific plan") and to prepare a design level of detail normally not seen until the design review phase of most projects. There are many philosophical perspectives on "New Urbanism" currently being debated. While not the subject of this discussion, additional reading material is available for those interested.

The limitations of the design-oriented code approach should not be construed, however, to limit built-out communities from incorporating more extensive graphics in zoning codes, to developing design elements of the code or design guidelines to supplement the code, or to apply "design-oriented" principles to appropriate larger parcels for development or redevelopment.


Type of Code




· Includes "districts," "uses", and "dimensional standards."

"Proscriptive": prohibits development not consistent with code.

· Generally text-based

· Base districts

· Use classifications

· Development standards: setbacks, height, lot size, density, floor-area ratio.

Flexible Zoning

a. Overlay Zones or Combining Districts

· Applies special standards over area or specific site

· Single-story height

· Pedestrian-oriented

· Floodplain

b. Planned Development

· Allows flexibility from standard rules to permit mixed uses, creative design, and/or public benefits

· Highly discretionary (negotiation) with findings usually required

· "Planned Development" zones

· "Planned Unit Development" zones

· "Planned Community" zones

c. Performance Zoning

· Regulates "impacts" of development, such as nuisance impacts, impervious surface, trip generation, etc.

· Sometimes combined with "point system" to compare planned development to basic zoning standards

· Nuisance (odor, noise, vibration, glare, toxics, etc.) standards in industrial or commercial zones

· Performance criteria (floor area, impervious surface, trip generation, etc.) to compare development alternatives

d. Incentive Zoning

· Flexibility to achieve objectives through "incentives" such as density or floor area bonuses in exchange for historic preservation, affordable housing, etc

· Exemption from FAR for child care facilities

· FAR bonuses for preserving historic structures

· Density bonuses for affordable housing

Design-Oriented (New Urbanist, "Form" Codes)

· Graphic-based and design approach to outlining regulations, including design "typologies" for homes, shopfronts, public spaces, streetscapes, etc.

· "Prescriptive": outlines what is expected of development, especially design.

· Uses and dimensional standards downplayed or not needed.

· Emphasizes "New Urbanist" principles

· Traditional neighborhood development (TND) zone

· Urban village zone

· Transit-oriented development (TOD) zone

· "Regulating plan" to outline design typologies


Type of Code




· Fairly easy for City staff to implement and for the public to interpret, if well organized.

· Familiar to professionals, staff, public officials, and public.

· Flexibility for varied design within parameters of use and dimensional standards.

· Lack of flexibility to address different site characteristics and surroundings.

· Does not prescribe what is expected, allowing for uncertainty as to product design.

Flexible Zoning

a. Overlay Zones

· Flexibility to impose specific requirements for area-specific or site-specific needs.

· May result in multiple and confusing districts and requirements.

b. Planned Development

· Flexibility to allow creative design, mixed uses, and to achieve public benefits.

· Can involve all parties in solution.

· Highly discretionary process leads to high degree of uncertainty.

· Negotiations may result in perceptions of public "giveaway" to or unreasonable "extractions" from developer.

· Difficult to monitor over time.

c. Performance Zoning

· Flexibility to vary uses, density and intensity of development and to address impacts instead.

· Impact approach may not address site-specific conditions or constraints.

· Difficult to implement - complex calculations.

d. Incentive Zoning

· Optional to developer

· May provide public amenities with "win-win" approach.

· Incentives may not be used, and amenities not provided

· Bonus and benefit may not be perceived as equivalent.

Design-Oriented (New Urbanist or "Form" Codes)

· Graphics are more readily understood by public, public officials, and professionals.

· "Prescriptive" approach outlines design visually.

· Integrates "New Urbanist" principles of mixed-use and pedestrian orientation.

· Useful for developing areas and some infill sites.

· Not readily applicable to built-out urban or suburban areas.

· Requires much up-front effort to develop regulating plan and design specifics.

· Does not provide much design flexibility for applicants, unless they are highly involved in initial design planning.

D. Format and Organization Options

Options for format and organization of zoning codes in many respects follow the type of code used. Some of the key issues to be considered in developing the format and organization of a Zoning Ordinance include:

1. Text v. graphics - Most traditional zoning codes emphasize text, and include few if any graphics or tables to help explain the code's provisions. Increasingly, and particularly as computers have allowed for ready production of graphics and tables, communities have opted to include more extensive figures and tables to at least supplement the text. The legal implications of graphics and tables are a further consideration.

2. Design Orientation - The "New Urbanist" approach to zoning codes is to replace the text orientation and use-driven code with a design-oriented format, as discussed in Part C. The format consists of a "regulating plan" and an accompanying code that primarily indicates the desired building forms (typology), such as for "clustered condominiums" or "medium intensity office." This kind of code is again most applicable in newly urbanizing areas or redeveloping parcels. An option in developed communities is to prepare "design guidelines" to support the desired design of residential and/or commercial development. If such guidelines are used, they are typically located outside of the zoning ordinance, though the code may provide direction as to how they are to be used (mandatory v. voluntary, by staff v. design review board, etc.).

3. Organization to emphasize uses and development standards - Zoning codes sometimes comprise long lists of sections dealing with procedures, administrative processes, definitions, and other provisions preceding or interspersed with the allowable uses and development standards of the code. Since most readers are specifically interested in the allowable uses and the relevant development standards, recent zoning codes more often place these regulations more prominently toward the front of the ordinance, and relegate procedures, administrative provisions, and definitions to later in the code.

4. Interpretations - Traditional codes have often been silent regarding how interpretations of the code are to be made and memorialized. This sometimes means that staff makes interpretations and the public may not be aware of their existence or application. More recent codes frequently provide a section to outline the authority of staff to make interpretations, and usually provide for appeals from those interpretations to the Planning Commission or City Council.

5. Reference to Comprehensive Plan and Interpretations - Zoning codes frequently provide reference to related provisions or definitions so that the reader is assured of knowing all that pertains to a specific zoning topic or site. They may also provide reference to relevant Comprehensive Plan policies that would assist the reader to better understand the intent of the regulations. Online capabilities make it relatively easy to provide links that tie directly from the code to the plan. Another issue to consider is to provide references to related interpretations, which also reside outside of the zoning ordinance.

6. Unified Development Codes - Unified development codes have become more prevalent in the past two decades in an attempt to locate all development-related regulations in one code. Typically, the zoning code, subdivision code, and building codes (and sometimes others, such as a site development code) comprise separate titles or chapters of a city's Municipal Code. The Unified Development Code approach combines most or all of the related codes into a single title.

With a Unified Development Code, an interested party (applicant, public, staff, public officials) knows that everything they need to know about development of an area or parcel should be found in the unified code. However, there is often so much information in a unified code that it is very difficult to focus on what that person wants to find, especially where some of the sections (like subdivisions) are frequently not applicable. The size of a unified code alone can be daunting to those who would use it to know only a few things.

7. Separate Zoning Code from Municipal Code - Another approach to consider is to separate the Zoning Ordinance from the remainder of the Municipal Code, so that it is not bound by the same formatting and other conventions as the remainder of the Municipal Code. This is very unusual. A city may, however, publish the Zoning Ordinance separately for the purpose of public distribution, and perhaps incorporating additional explanatory materials, graphics, procedures, etc. These are primarily format issues that should be determined by a community with the support of its City Attorney.

Attachments 1 and 2 outline the format and organization characteristics of the zoning ordinances of ten communities, six of which are in California (including Palo Alto) and the remainder from throughout the country. The codes listed in Attachment 1 are generally "Euclidean-based" codes, most of which also incorporate some flexible zoning provisions. The codes in Attachment 2 are included to represent some of the "design-oriented" codes, though the extent of the design provisions varies considerably from one to another.

E. Palo Alto’s Zoning Code 

The existing Palo Alto Zoning Code is a Euclidean-based ordinance with several "flexible" zoning techniques incorporated over the years. The basic ordinance includes zoning district and use provisions, with dimensional standards including lot size, lot width, setbacks, height, densities, and FAR. An extensive number of overlay and combining districts are provided to further restrict specific parcels or geographic areas for specific purposes (e.g., neighborhood preservation, ground floor retail, pedestrian shopping, landscaping, etc.).

Performance standards are included in the Palo Alto code for such factors as parking, site coverage, lighting, usable open space, recycling storage and trash disposal, noise, outdoor sales and storage, nuisances and offensive conditions, and landscaping. Incentive zoning is provided in very limited instances, including FAR bonuses for historic protection and seismic upgrades, and density bonuses for affordable housing.

The Planned Community (PC) zone is a significant flexible zoning tool as well, providing the flexibility to deviate from other standards subject to findings, including provision of adequate public benefits and consistency with the Comprehensive Plan. There has been considerable discussion in the community about the "public benefits" provided by the PC zone, the extent of deviations permitted, and the substantial discretion involved.

The current Zoning Ordinance does not incorporate any of the design-oriented elements of the New Urbanist codes.

Format and Organization

The Palo Alto Zoning Ordinance is poorly organized, it lacks divisions or articles to indicate topic areas, and instead consists of 49 consecutive chapters, which have just been added to over time. The Ordinance includes 32 distinct zoning districts, with a number of additional combinations of districts possible as well. Many of the requirements for special uses, such as alcoholic beverage establishments, are buried in obscure district regulations or in procedures.

Graphics and tables are included in the Ordinance, but are not as purposeful as they could be, are not high quality, and are sometimes not in close proximity to the provision to which they relate. There is no existing interpretation process in the Ordinance, and purpose statements are provided only initially for each zoning district. The Ordinance is accessible online with standard table of contents and word search capabilities, and links are provided to code sections referenced in the Ordinance (a feature not generally found in other online ordinances).

Policy Considerations and Work Program Implementation

The City of Palo Alto will need to determine the type, format and organization of its Zoning Ordinance as part of the Update process. Some initial policy considerations, based on the prior discussion, include:

  • To what extent should the Zoning Ordinance attempt to incorporate a "design-oriented" (New Urbanist) format? Developing a "design-oriented" code for a largely developed community would require extensive resources and time to prepare the level of design detail and consensus necessary. While such an approach may be problematic for Palo Alto, there are likely to be several opportunities for the use of a "form" code approach to regulate infill and redevelopment parcels, or even to govern manageable areas with a consistent design approach. A "hybrid" ordinance could provide for a design approach to some of the new zoning districts to be created, within the context of a more traditional code format.

  • Should the Zoning Ordinance remain consistent with the format of the Municipal Code, and remain embodied within that code, or removed from the Code entirely? If the ordinance remains as Title 18 in the current Municipal Code, a separate version, with added explanatory material, could later be developed for public use.

  • Should the City develop a unified code, to include the provisions of zoning, building, and subdivision in one document? If not, what provisions outside of the current Title 18 should be incorporated into the Zoning Ordinance? While the subdivision and building codes may clutter the ordinance and make it less usable, there should be a determination as to what provisions of Title 16 (and others) should be incorporated into the Zoning Ordinance, including:

    Provisions Related To:

    Municipal Code Section





    Architectural Review


    Historic Preservation


    Setback Lines



    Additionally, based on the prior discussion, the following elements of format and organization should be considered as the Zoning Ordinance Update work program proceeds:

  • There are a multitude of opportunities to use flexible zoning techniques in the updated ordinance, including the provision of overlay zones and incentive zoning, and refinement of the City's planned community zoning district. These all provide valuable tools to tailor development to the sensitivity of specific sites while allowing applicants design flexibility.

  • Graphics are an important tool for conveying understanding of the ordinance, regardless of the form taken. The City Attorney will need to be involved to establish parameters for the use of graphics and their relationship to the text of the Ordinance.

  • Purpose statements appear to be an important element in many codes, and the City should identify where the inclusion of such statements would clarify the intent of zoning districts, regulations, or procedures. The purpose statements for zoning districts should refer to and use, where possible, language from the Comprehensive Plan for that land use.

  • Although the Update effort should assure that regulations are as complete and clear as possible, interpretations of the ordinance will always be necessary. Provisions can be included to allow for interpretations by staff, with appropriate appeal procedures and requirements for documenting adopted interpretations.

  • The City should identify opportunities to provide references in the ordinance to related code sections, and should consider whether to provide references as well to relevant Comprehensive Plan provisions, and to related interpretations. The online version of the ordinance may make cross-referencing easier to implement and understand.

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Last Updated: October 15, 2007