3.3 Clearances

Clearances are the minimum distances between elements in, under and above the street right-of-way. Clearance requirements are a key factor in how space within the right-of-way and on private property adjacent to the right-of-way can be used. Maintaining appropriate clear distances between certain elements in the right-of-way and on private property is necessary for a variety of reasons. Safety is a key consideration—for the traveling public, the property owner and for operations and maintenance crews who must access elements in the right-of-way for routine maintenance or repair. Appropriate clearances also enable the proper growth and development of trees and landscaping, and help protect and maintain both overhead and underground utilities.

This section describes required lateral and vertical clearances as well as special circumstances where additional clearance requirements may apply. The minimum clearances defined in this section are requirements. When minimum clearances cannot be met due to site condition constraints, the City staff will work with the applicant to determine an acceptable solution. Deviations from the standard clearances in this section are considered on a case by case basis and are evaluated by SDOT, SPU, SCL and other departments as needed. For additional information on setbacks and clearances shall be used for On-Site Stormwater Management BMPs in the public right-of-way, see the Drainage section.

Links to Standard Plans and Specifications

Standard Plan 030: Standard Location for Utilities (Residential Street)

Design Criteria

See Figure K for sight lines at an intersection and set backs from a stop sign.  See Figure L for vertical and horizontal clearances within the right-of-way.

Figure K: sight line at an intersection

Figure L: Vertical and horizontal clearances.

Figure LM: sidewalk corner clearance zone

Lateral Clearances

Notes: When placing objects in the right-of-way that have an operational footprint greater than the fixture itself, the minimum clearance shall be measured from the edge of the operational footprint. This is a minimum clearance. Clearances for projects shall be determined by evaluating the planned roadway cross section and providing enough clearance to allow for installation of such future improvements.

*Anything bolted to the ground excluding traffic control signs, trees (see tree clearances section) and parking meter posts

The sidewalk at an intersection should be clear from the corner of the property line to five feet on either side of the corner or from the corner of the property line to the far edge of a marked crosswalk or curb ramp, whichever is larger, and extended to the curb face. See Figure LM above.

Vertical Clearances

Clearances from Trees

For more information about clearances and trees, including conditions for deviating from the standard clearance listed below due to site constraints; refer to the section on Street Trees. Factors to consider for a deviation from the standard required clearances between street trees and utilities may include the depth and age of the pipeline, the possible use of root barriers. Overhead utilities also impact the pruning of trees in Seattle. See Seattle City Light Construction Standards for more information.

Clearances from Railroad Facilities

Certain requirements apply if a project is in the on, over, under, or in the vicinity of land or facilities owned and/or operated by railroad operators. There are three reference points for determining clearances: 1) the franchise agreement for a particular piece of railroad in the right-of-way; 2) state requirements; and 3) federal requirements. Whether state or federal (or both) requirements apply depends on the track classification and function.

Seattle is a First Class City and acts in place of the Washington State Utilities and Transportation Commission (UTC) when interacting with the rail companies concerning railroad tracks and crossings (RCW 35.22 – RCW 35.22.340).  General guidance on clearance is listed below and is more fully listed in WAC 480-60 Railroad Companies – Clearances, but it is incumbent on the developer to contact railway companies for all work within 25 feet of a rail crossing or track to confirm there are no extenuating circumstances that would affect the project or rail operation.

The following rail companies operate in the City of Seattle and operate rail lines, rail crossings and spur tracks in the City of Seattle:

Other clearances pertaining to railroads shall conform to Clearance Rules and Regulations Governing Common Carrier Railroads prescribed by the Washington Utilities and Transportation Commission. Minimum clear distance above a railroad track shall be 23 ½ feet from the top of the rail.

If your project is on or adjacent to property owned by railroad operators, contact the operator for information about required clearances or additional permit requirements.

Bicycle Parking Clearances

In addition to the clearances defined in the table below, bicycle parking facilities must not encroach upon a minimum of 6 feet of clear sidewalk space after considering operational area including parked bicycles.

Utility Clearance Requirements

Applicants who are developing a new project must pay attention to the potential conflicts between existing electrical facilities in the public right-of-way and their new building during project planning, design, demolition and construction. The following criteria applies:

Minimum horizontal and vertical clearances between overhead power distribution and buildings or other structures: The Seattle City Light (SCL) Overhead Power Distribution requires a minimum horizontal and vertical clearance from buildings and structures. The purpose of this clearance is to keep the general public and workers without high voltage electrical expertise out of harms way.

Clearances also provide adequate space for qualified electrical workers to operate safely and efficiently during construction and long term operations and maintenance activities. Additional clearances are required to allow for regular building maintenance such as window washing activities. For more information on utility clearances, see the utility section.

Utility vaults should be located in the landscape/furniture zone but outside of any bioretention or rain garden.  See drainage clearances and set backs for more information.

Zero lot line developments

Clearances for structures: Many existing and new buildings are constructed to the edge of right-of-way, especially within downtown and urban centers. When placing structures on private property in areas close to the right-of-way edge, identify the full operational footprint to avoid right-of-way impacts. When designing access points, keep in mind that doors are not allowed to swing out into ROW. When siting structures, clearances must be provided from the operational footprint of the structure rather than from the edge of the structure itself (bike rack with bicycles or bench with people sitting).

Clearance for electric utilities: Zero lot line developments often encounter clearance problems with high voltage overhead and underground electrical facilities and wires. Land use setback requirements alone, for example when minimal front yard setbacks are allowed, are likely not adequate to account for required clearances from overhead electric utilities. Note that clearances are also required where electrical facilities are located in alleys. Thus, proposed buildings may need to be located further back from property lines to accomplish required clearances.

Permit applicants must adhere to electric utility clearance requirements. Please contact Seattle City Light to arrange a meeting as early as possible in your design process. We recognize that each proposed development location, adjacent utilities, streetscape, and development request is unique. Even if poles and wires are not immediately adjacent to your property now, it is best to assume clearances are needed until you meet with Seattle City Light and verify otherwise. Additional and relocated infrastructure will be needed to serve the demand for growth. See Seattle City Light’s Construction and Design Standards for more information.

Refer to Electrical Utility Clearances Notes

Design Considerations

The applicant is advised to document the existing site conditions early in the design phase to identify any elements that may have a required clearance to help avoid possible costly site modifications during permitting.