TRN-1.22 - Infill Development on Streets with an Existing Sidewalk Corridor

Certain terms in this Administrative Rule are defined in Portland City Code Chapter 33.445 (Historic Resource Overlay Zone) and 33.846 (Historic Resource Reviews).Pursuant to Rulemaking Authority under Portland City Code Chapter 3.12.010

Portland City Code Chapter 17.28: Sidewalks, Curbs and Driveways.

Portland City Code Chapter 17.88.020: For Buildings and Planning Actions.

Effective Date

This administrative rule is effective two weeks after adoption.

I. Background

The Portland Pedestrian Design Guide (TRN 1.092) serves as the City's primary guidance on how sidewalks should be built throughout Portland to ensure they are context-appropriate and accessible to people of all ages and abilities. ­

Table B-3 of the Pedestrian Design Guide sets the minimum required widths for sidewalk corridors overall and for each zone of the sidewalk corridor, based upon the roadway's Street Design Classification. Section B.1.3.4 provides certain limited exceptions to the sidewalk widths prescribed in Table B-3.

This rule is intended to improve the public works appeals process by providing more detail on these exceptions. This rule may be applied at time of building plan review to grant an administrative exception.

II. Existing Sidewalks on Local Streets 

If a property meets the conditions described in this section, it will be exempt from the application of TRN-1.092 as it pertains to pedestrian corridor design configuration. No additional right of way dedication will be required. Once a determination has been made by City staff, that determination will be used by the City to guide determinations for other properties on the block. Properties on corner lots will have frontages evaluated separately. All construction must substantially conform with any determination made under this rule.

A block, for the purposes of this rule, includes the block face from intersection to intersection. Furnishing zone widths do not include the curb.

A. Sidewalk Sufficiently Close to Standard

A property for which all of the following are true will be granted an administrative exemption and allowed to maintain the existing sidewalk. The existing sidewalk configuration will be accepted as the standard sidewalk configuration for the length of the block along the same side of the street.

1. The property is zoned residential RM1, RM2, R-2.5, R-5, R-7, R-10, R-20, RF, employment EG1 or EG2, or industrial IG1, IG2, or IH;
2. The sidewalk corridor (curb, furnishing zone, sidewalk and frontage zone) is the same configuration the length of the block along the side of the street upon which the property is located. On blocks with non-eligible zoning at one end, the sidewalk configuration is the same for the portion of the block that falls within any eligible zone listed in section II.A.1 (see example in Figure 1);
3. Any Building Permit must be in conformance with Land Use decisions made for the site;
4. The abutting street has a street design classification of Local Street and a traffic classification of Local Service in the City's Transportation System Plan;
5. The existing sidewalk is either:
   1. Built with a pedestrian through zone within 1 foot of the standard width identified in TRN-1.092, Table B-3, and a furnishing zone at least 3 feet wide;
   2. A curb-tight sidewalk with a minimum width of 6 feet and all utility poles and furnishings located behind the sidewalk; or
   3. For sidewalks built with a pedestrian through zone at least 6 feet wide and a furnishing zone between 2 and 2.5 feet wide see section II.B below.

B. Modifying a Narrow Furnishing Zone

A sidewalk corridor configuration with a furnishing zone narrower than 3 feet does not meet the City of Portland's Tree Planting Standards. Therefore, a building permit or land use review applicant must modify the sidewalk to create tree planting spaces if:

1. The property meets conditions 1-3 and 5 in section II.A above and
2. The existing sidewalk has a furnishing zone between 2 and 2.5 feet wide and a 6-foot-wide pedestrian through zone.

Tree planting spaces are created by widening the furnishing zone at specific locations (to be determined by Urban Forestry) while maintaining a minimum 5-foot-wide pedestrian through zone, as specified in standard detail P-553.

This modification will become the standard sidewalk configuration for the length of the block along the same side of the street.

View full size image of An example of blocks on NE 15th Ave and NE 16th Ave that have non-eligible zoning on one end. In this example, the sidewalk configuration must be the same on the portion of the block with eligible R2.5 zoning. The sidewalk on the frontage of the properties with CM2 zoning may be wider.

III. Historic Resource Overlay Zones

Within Historic Resource Overlay Zones, there are sometimes instances in which the requirement to construct a wider sidewalk with development may conflict with established building façade lines that contribute to the coherency of a Historic/Conservation District. A historic or conservation district is not merely a collection of individually significant historic resources, rather the district is the resource. It is notable for its coherency and integrity, and that has been determined worthy of preservation. To respect and complement the district, new development should seek to blend in with the existing fabric.

1. For Civic and Neighborhood Main Streets (as identified in the Portland Transportation System Plan) located within a Historic Resource Overlay Zone, sidewalk corridors may be a minimum of 12 feet wide (in accordance with sidewalk corridor requirements for "Neighborhood Corridors") rather than 15 feet wide as prescribed by table B-3 to assist in the preservation of Historic building façade lines.
   1. Streets that meet the above definition include NW 23^rd Ave from W Burnside St to NW Kearney St; NW 21^st Ave from NW Davis St to NW Marshall St; SE Grand Ave from SE Main St to SE Ankeny St; N Russell St from N Interstate Ave to N Albina Ave; NW 4^th Ave from W Burnside St to NW Glisan St.
2. A sidewalk narrower than 12 feet along a Civic or Neighborhood Main Street within a Historic Resource Overlay Zone may be approved through the Public Works Alternative Review process if the Director of the Portland Permitting & Development Bureau of confirms that the historic character of the block requires the preservation or restoration of the Historic building façade line.
3. Where a sidewalk corridor less than 12 feet is approved along a Civic or Neighborhood Main Street within a Historic Resource Overlay Zone, all sidewalk level right-of-way encroachments and street activation activities approved and permitted by PBOT must occur fully outside of the Pedestrian Through Zone (e.g., within the curb/parking zone). This does not apply to elements such as canopies, awnings or balconies that are located above the pedestrian level and are governed by the Administrative Rule TRN-8.08 (Encroachments in the Public Right-of-Way.)
4. Civic and Neighborhood Main Streets located within Design Overlays are subject to the provisions of the Pedestrian Design Guide Table B-3 sidewalk corridor width requirements.

IV. Flag Lots

As determined by City staff, typical frontage improvements for residential development on existing flag lots with a pole width of less than 25-feet may not be required where frontage improvements do not exist or meet standards on the lot immediately adjacent to the pole and there is not an established curb/sidewalk pattern along the block.

V. Planned Unit Developments (PUDs)

New single-family homes on vacant lots within existing planned unit development (PUDs) in which at least 90% of the homes have been built may be constructed with improvements consistent with the established improvements within the development in lieu of typical frontage requirements.

The applicant is responsible for documenting the 90% development threshold to the satisfaction of City staff.

VI. Existing Sidewalk Corridors Exceeding Required Widths

Properties with existing sidewalk configurations that exceed current corridor requirements will be accepted as the standard sidewalk configuration for the property and will not require modification.

VII. Discussion

This Administrative Rule was updated in 2024 to reflect current sidewalk standards.

A. Existing Sidewalks on Local Streets (Section II) 

The City's first Pedestrian Design Guide was developed in 1998 and updated in 2022. Many sidewalks in Portland were built before the adoption of current sidewalk standards, or were built to County standards before an area was annexed into the City. Section A of this rule describes situations where infill development on a local street can match a sidewalk configuration that is present for the full length of the block, provided it meets certain dimensional requirements. In some instances, this allows for maintaining curb-tight sidewalks, which are common in some areas. This includes locations with steep topography and industrial areas, where sidewalks were sometimes constructed curb-tight with trees planted behind the sidewalk.

Example:

A property on a local service traffic street and local service walkway, zoned R-5, with an existing frontage consisting of a 3-foot-wide furnishing zone and a 5-foot-wide sidewalk along the entire block. TRN 1.092 requires a 4-foot planting strip and 6-foot-wide sidewalk. This rule allows this configuration to remain for redevelopment purposes with no public works appeal required.

1. Historic Resource Overlay Zones (Section III)

PBOT briefed both the Design Commission and Historic Landmarks Commission on the updated Pedestrian Design Guide twice in 2021, at which time both commissions concurred that their primary concern is protecting the consistent street walls on the linear commercial corridors ("Main Streets") within Historic and Conservation Districts. Both commissions expressed that a consistent street wall on these linear commercial corridors within Historic Resource Overlay Zones is its primary character-defining element and that new development should not introduce a staggered street wall in this context.

This exception for Historic Resource Overlay Zones was developed in collaboration with Bureau of Development Services staff and Design and Historic Landmarks commissioners appointed to a joint subcommittee to work with PBOT to develop an approach to sidewalk setback requirements within Historic Resource Overlay Zones in October 2021.