A. 
Special corner features are permitted by District as shown in Table 18-3, “District Standards.”
B. 
A special corner feature is a distinctive building element used to emphasize the corner of a building at an important intersection. See the Southcenter Design Manual, Section 9, “Corner Treatments,” for additional guidance.
C. 
Special corner feature masses may encroach up to 2 feet into the required setback areas but may not encroach into the public right-of-way. See TMC Section 18.28.210, “Front Yard Encroachments.”
D. 
Special corner features may exceed the permitted height limit by 20 feet, up to a maximum of 115 feet.
(Ord. 2741 § 4 (part), 2024)
A. 
Front Yard Landscaping Types.
1. 
Frontage Improvements per Corridor Type.
a. 
When public frontage is constructed to meet the Corridor standard, any other front yard landscaping requirement shall be waived. Exceptions: perimeter parking lot landscaping (see TMC Section 18.28.240.B.6) and blank wall screening standards (see Section 15 of the Southcenter Design Manual) still apply, where applicable. To qualify for the waiver, public frontage improvements must be made along the entire street fronting the parcel. Public frontage improvements may continue into a courtyard or plaza.
b. 
For Corridor Types that contain a planting strip (Urban, Commercial, Freeway Frontage and Workplace), minimum plantings shall consist of:
(1) 
Trees at the spacing listed per Corridor Type.
(2) 
1 shrub per 4 linear feet of frontage, excluding curb cuts, or a planted berm at least 24 inches high.
(3) 
Sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the landscape area not needed for trees and shrubs. Groundcover must be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around each tree.
2. 
Paved / Sidewalk Extension.
a. 
Provide paved pedestrian areas along the back of sidewalk, such as plazas or courtyards that enhance/enlarge the public frontage.
b. 
Only permitted on parcels where the public frontage improvements meet the Corridor Standards in this code.
c. 
Must meet applicable pedestrian space design requirements (see TMC Section 18.28.250.E.).
3. 
Streetscape.
a. 
Cover front yards with landscaped, pervious surfaces that visually soften and enhance the built environment.
b. 
Provide pathways connecting the public sidewalk to the front door through parking areas.
c. 
1 tree per 500 square feet of landscaped setback area or 1 tree per 20 to 30 linear feet of frontage (depending on tree species and location of underground or at-ground utilities and excluding curb cuts), whichever results in more trees.
d. 
Where there are existing street trees, the additional trees required by this section shall be planted behind the sidewalk in an informal pattern and consist of a mix of deciduous and evergreens.
e. 
Minimum 1 shrub per 4 linear feet of frontage, excluding curb cuts, or a planted berm at least 24 inches high.
f. 
Sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the landscape area not needed for trees and shrubs. Groundcover shall be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around each tree.
4. 
When there is an existing sidewalk that does not meet the Corridor standard for public frontage and the sidewalk remains in place, the required front yard landscaping width shall be measured from the back of sidewalk or edge of right-of-way, whichever is further from the road centerline.
B. 
Side and Rear Yard Landscape Types
(see Figure 18-46).
Figure 18-46: Illustrating the various side and rear yard treatment standards and options
1. 
Groundcover.
a. 
This is appropriate where the adjacent uses are compatible and no screening is necessary.
b. 
Cover side and rear yards with landscaped, pervious surfaces. Landscaping treatment at a minimum shall consist of sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the landscape area not needed for trees and shrubs. Groundcover must be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around each tree.
2. 
Shared pathway along or adjacent to the property line with landscaping. This is a desirable configuration that can enhance pedestrian circulation and provides an efficient use of space. This treatment requires a recorded agreement with applicable adjacent property owner(s).
3. 
Shared internal drive along or adjacent to the property line. This is a desirable configuration for non-residential uses that can enhance circulation and provides an efficient use of space.
4. 
Moderate Screening.
a. 
Provide light visual separation along property lines between somewhat incompatible development.
b. 
Landscaping designed to screen parking/service areas and blank side and rear building façades.
c. 
Landscaping that maintains views to building entrances and signage.
d. 
1 tree per 20 linear feet of property line (excluding curb cuts) spaced regularly (except where there are conflicts with utilities) and consisting of a mix of deciduous and evergreen trees along the applicable property line.
e. 
1 shrub per 4 linear feet of property line, excluding curb cuts.
f. 
Sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the yard area not needed for trees and shrubs. Groundcover must be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around each tree.
5. 
Heavy Screening.
a. 
Provide heavy visual separation along property lines between highly incompatible development, such as warehousing and residential uses.
b. 
Landscaping designed to screen parking/service areas and blank side and rear building façades.
c. 
1 tree per 20 linear feet of property line (excluding curb cuts) spaced regularly (except where there are conflicts with utilities) and consisting of at least 50% conifers along the applicable property line (75% along property line adjacent to residential uses).
d. 
Privacy screening utilizing evergreen shrubs, screening walls or fences (up to 7 feet tall) is allowed.
e. 
Sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the yard area not needed for trees and shrubs. Groundcover must be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around each tree.
(Ord. 2741 § 4 (part), 2024)
A. 
The provisions herein are applicable to setbacks, public frontage areas, open space, and other areas on-premises. These regulations address plant materials and design, visibility, irrigation, landscape plans, utility and service areas.
B. 
General Landscaping Requirements.
1. 
Plant Materials.
a. 
A mix of evergreen trees and evergreen shrubs shall be used to screen blank walls.
b. 
All plant material shall meet the most recent American Standards for Nursery Plant Stock (ANSI Z60.1).
c. 
Evergreen trees shall be a minimum of 6 feet in height at time of planting.
d. 
Deciduous trees shall be a minimum 2.5 inch caliper six inches off the ground when installed.
e. 
Shrubs shall be at least 18 inches in height at time of planting.
f. 
Existing vegetation may be used to meet the perimeter landscaping requirements. All significant trees located within any required perimeter landscape area that are not dead, dying, or diseased and that do not pose a safety hazard as determined by the City or a qualified arborist shall be retained and protected during construction with temporary fencing or other enclosure, as appropriate to the site. The area designated for protection will vary based on the tree’s diameter, species, age, and the characteristics of the planted area. Property owners may be required to furnish a report by an International Society of Arborist (ISA) certified arborist to document a tree’s condition. The Director may require that an ISA certified arborist be retained to supervise tree protection during construction. Grade changes around existing trees are to be avoided whenever possible.
g. 
New plant materials shall include native species or non-native species that are drought tolerant and have adapted to the climatic conditions of the Puget Sound Region. There must be a diversity of tree and shrub genus and species in the site landscaping, taking into account species in existing development around the site.
h. 
No species that are listed on the State or King County noxious weed lists may be planted.
i. 
Plant materials shall be selected that reinforce the landscape design concept, and are appropriate to their location in terms of hardiness, tolerance to urban conditions, maintenance needs and growth characteristics. Large and medium canopy tree species are required, except where there is insufficient planting area (due to proximity to a building, street light, above ground or underground utility line, etc.).
2. 
Visibility.
a. 
Design of new landscaping and maintenance of existing landscaping shall consider Crime Prevention Through Environmental Design (CPTED) principals and visibility for safety and views. Appropriate plant species shall be specified to avoid the need for excessive maintenance pruning. Trees along the street frontages, as they mature, shall be limbed up to a minimum height of 6 feet (8 feet where they extend over sidewalks) to allow adequate visibility and clearance for vehicles. Trees may be pruned to improve views of signage and entryways by using such techniques as windowing, thinning, and limbing-up. However, no more than 1/4 of the canopy may be removed within any 2-year period, and the crown should be maintained to at least 2/3 the height of the tree. All pruning shall be done in accordance with ANSI Standard A-300 specifications. Trees may not be topped for any reason. Trees may only be pruned to lower their height to prevent interference with an overhead utility or electrical line.
b. 
Landscaping shall not obstruct views from or into the driveway, sidewalk or street. Landscape design shall allow for surveillance from streets and buildings and avoid creating areas that might harbor criminal activity.
c. 
Landscaping at crosswalks and other locations where vehicles and pedestrians intersect must not block pedestrians’ and drivers’ views.
d. 
Evergreen shrubs and trees shall be used for screening along rear property lines, around solid waste/recycling areas and mechanical equipment, and to obscure grillwork and fencing associated with subsurface parking garages.
3. 
Soil Preparation and Planting.
a. 
For trees and plants planted in sidewalks and parking lots, or in limited areas of soil volume, structural soils (Cornell University “CU” product or similar) must be used to a preferred depth of 36 inches, to promote root growth and provide structural support to the paved area. Minimum soil volumes for tree roots shall be 750 square feet per tree (see specifications and sample plans for CU-Structural Soils). Trees and other landscape materials shall be planted per specifications in “CU Structural Soils – A Comprehensive Guide” or using current BMPs subject to administrative review and approval of the technical information report (TIR.) Suspended pavement systems (Silva Cells or similar) may also be used if approved.
b. 
For soil preparation in bioretention areas, existing soils must be protected from compaction. Bioretention soil media must be prepared in accordance with standard specifications of the Surface Water Design Manual, adopted in accordance with TMC Chapter 14.30, to promote a proper functioning bioretention system. These specifications shall be adhered to regardless of whether a stormwater permit is required from the City.
c. 
For all other plantings, soils must be prepared for planting in accordance with specifications to restore soil moisture-holding capacity in accordance with TMC Chapter 16.54, Grading, regardless of whether a stormwater permit is required by the City.
d. 
The applicant will be required to schedule an inspection by the City of the planting areas prior to planting to ensure soils are properly prepared.
e. 
Installation of landscape plants must comply with best management practices including:
(1) 
Planting holes that are the same depth as the size of the root ball and 2 times wider than the size of the root ball.
(2) 
Root balls of potted and balled and burlapped (B&B) plants must be loosened and pruned as necessary to ensure there are no encircling roots prior to planting. At least the top 2/3 of burlap and all straps or wire baskets are to be removed from B&B plants prior to planting.
(3) 
The top of the root flare, where the roots and the trunk begin, should be about one inch from the surrounding soil. The root ball shall not extend above the soil surface.
(4) 
If using mulch around trees and shrubs, maintain at least a 3-inch mulch-free ring around the base of the plant trunks and woody stems of shrubs. If using mulch around groundcovers until they become established, mulch shall not be placed over the crowns of perennial plants.
4. 
Irrigation.
a. 
The intent of this standard is to ensure that plants will survive the critical establishment period when they are most vulnerable due to lack of watering.
b. 
All required plantings must be served by a permanent automatic irrigation system.
(1) 
Irrigation shall be designed to conserve water by using the best practical management techniques available. These techniques may include, but not be limited to: drip irrigation to minimize evaporation loss, moisture sensors to prevent irrigation during rainy periods, automatic controllers to insure proper duration of watering, sprinkler head selection and spacing designed to minimize overspray, and separate zones for turf and shrubs and for full sun exposure and shady areas to meet watering needs of different sections of the landscape.
(2) 
Exceptions to the irrigation requirement may be approved by the Director, such as xeriscaping (i.e., low water usage plantings), plantings approved for low impact development techniques, established indigenous plant material, or landscapes where natural appearance is acceptable or desirable to the City. However, those exceptions will require temporary irrigation until established.
5. 
Landscape Plan Requirements.
a. 
A Washington State licensed landscape architect shall prepare and stamp the landscape plans in accordance with the standards herein. Detailed plans for landscaping and screening shall be submitted with plans for building and site improvements. Included in the plans shall be type, quantity, spacing and location of plants and materials; typical planting details; and the location of irrigation systems. Underground and at-ground utilities shall be shown on the plans so that planting conflicts are avoided.
b. 
Installation of the landscaping and screening shall be completed and a Landscaping Declaration submitted by the owner or owner’s agent prior to issuance of the Certificate of Occupancy. If necessary due to weather conditions or construction scheduling, the installation may be postponed to the next planting season if approved by the Director and stated on the building permit. A performance assurance device equal to 150% of the cost of the labor and materials must be provided to the City before the deferral is approved.
6. 
Parking Lots.
a. 
Setback and Perimeter Landscaping:
(1) 
Surface parking lots shall set back a minimum of five feet from any open space, building façade, or Corridor back of sidewalk. The setback shall be designed and planted with:
(a) 
1 evergreen shrub per 4 linear feet of property line, excluding curb cuts.
(b) 
Sufficient live groundcovers of varying heights, colors and textures to cover, within 3 years, 100% of the yard area not needed for trees and shrubs. Groundcover must be planted with a minimum spacing of 12 inches on center for 4-inch pots and 18 inches on center for 1-gallon pots. If turf grass is being used as the groundcover, a 3-foot diameter ring of bark mulch is required around any tree.
(2) 
Surface parking lots shall be buffered from adjacent residential development with heavy screening in the side and rear setback areas.
b. 
Interior Parking Lot Landscaping:
(1) 
For surface parking lots adjacent to public or private streets, a minimum of 20 square feet of interior parking lot landscaping is required for each parking stall. In the Workplace District, a minimum of 15 square feet per stall is required for warehouse and light industrial uses.
(2) 
For surface parking lots located behind buildings or otherwise screened from public or private streets or public spaces, a minimum of 10 square feet of interior parking lot landscaping is required for each parking stall.
(3) 
Flexibility is allowed for the layout of parking lots and landscaped areas, but the goal is to provide shade from trees that are evenly distributed throughout the parking lot. Planting trees in continuous, landscaped planting strips between rows of parking is encouraged. This approach may also be combined with surface water management design. For parking lots adjacent to public or private streets, if landscape islands are designed into the parking lot layout to divide continuous rows of parking stalls, they must be placed at minimum spacing of every 10 parking spaces. For parking areas located behind buildings or otherwise screened from public or private streets or public spaces, if landscape islands are used, they shall be placed at a minimum of one island every 15 parking stalls.
(4) 
Landscape islands must be a minimum of 6 feet wide and a minimum of 100 square feet in area. All landscaped areas must be protected from damage by vehicles (curbs, tire stops, other techniques).
(5) 
Landscape islands shall be placed at the ends of each row of parking to protect parked vehicles from turning movements of other vehicles.
(6) 
A minimum of one large-canopy evergreen or deciduous tree or two medium-canopy trees are required for every 100 square feet of landscaped island, with the remaining area to contain a combination of shrubs, living groundcover, and mulch (see Figure 18-47).
Figure 18-47: A single tree planted with no other materials and little room for viability is not acceptable.
7. 
Utility and Service Areas.
Utility easements and other similar areas between property lines and curbing shall be landscaped and/or treated with dust and erosion control planting or surfacing. Trees proposed under overhead transmission lines shall be approved by the City on a case-by-case basis.
8. 
Street Trees in the Public Frontage.
a. 
Street tree spacing in the public frontage shall be as specified in the applicable Corridor Standards. For smaller stature trees (those with canopies at maturity of less than 20 feet), spacing should be every 20 feet. For larger canopy trees, spacing should be wider as appropriate to the mature spread of the tree. Spacing will also need to consider sight vision distance at intersections, driveway locations, and utility conflicts.
b. 
Street trees in the public frontage shall be planted to at least the following spacing standards:
(1) 
At least 3.5 feet back from the face of the curb and with an approved root barrier installed on the curb side.
(2) 
At least 5 feet from underground utility lines.
(3) 
At least 10 feet from power poles.
(4) 
At least 7.5 feet from driveways.
(5) 
At least 3 feet from pad-mounted transformers (except 10 feet in front for access).
(6) 
At least 4 feet from fire hydrants and connections.
c. 
When used, tree grates and landscaped tree wells shall be a minimum 36 square feet in size (6’ x 6’). Tree grates are not encouraged, but when used grates must have easily removable rings so that sections of grate can be removed incrementally as the tree matures. Tree well size may be adjusted to comply with ADA standards on narrower sidewalks. Root barriers must be installed at curb face. See TMC Section 18.28.240.B.3, “Soil Preparation and Planting,” for structural soil requirements.
d. 
Planting and lighting plans shall be coordinated so that trees are not planted in locations where they would obstruct existing or planned street or site lighting, while maintaining appropriate spacing and allowing for their size and spread at maturity.
9. 
Maintenance and Pruning.
a. 
Any landscaping required by this chapter shall be retained and maintained by the property owner for the life of the project in conformance with the intent of the approved landscape plan and this chapter. Maintenance shall include keeping all planting areas free of weeds and trash and replacing any unhealthy or dead plant materials.
b. 
Pruning of trees is only allowed for the health of the tree, to maintain sight distances or sight lines into commercial areas, or if interfering with overhead utilities. All pruning must be done in accordance with American National Standards Institute (ANSI) A-300 specifications. No tree planted by a property owner or the City to fulfill landscape requirements, or any existing tree, may be topped or removed without prior approval from the City. If a tree is topped or removed without approval, it shall be replaced with a new tree that meets the intent of this chapter within 120 days or the property owner will be subject to code enforcement and penalties as prescribed in TMC Chapter 8.45 and the issuance of a Notice of Violation in accordance with TMC Section 8.45.070. Options at the Director’s discretion are to require replacement of the tree with a new tree of similar species that will achieve a similar canopy size at maturity, replace the tree with multiple smaller diameter trees of an appropriate species (only if there are limitations on space or conflicts with utility infrastructure), and/or require an in-lieu fee for off-site tree replacement.
C. 
General Landscaping Considerations.
1. 
Plant Materials.
a. 
Drought resistant species are encouraged in order to minimize irrigation requirements, except where site conditions within the required landscape areas ensure adequate moisture for growth.
b. 
The mature size of selected tree species should be suitable to lot size, the scale of adjacent structures, and the proximity to utility lines.
c. 
In general, deciduous trees with open branching structures are recommended to ensure visibility to retail establishments. More substantial shade trees are recommended in front of private residences.
d. 
All trees should be selected and located so they will not obstruct views to showroom windows and building signage as they mature.
e. 
Evergreen landscaping (Figure 18-48) is appropriate for screening utility vaults, loading docks and some storage areas. (Also see TMC Section 18.52.050 for screening outdoor storage areas.)
Figure 18-48: Using evergreen landscaping to screen utilities
f. 
Species selection is very important in grouped plantings (Figure 18-49). Drought tolerant species are strongly recommended and monoculture plantings are discouraged. Low maintenance cost and low replacement costs are two advantages of planting drought tolerant species in grouped configurations. Low (24-30 inches) shrubs, perennial or groundcover plantings that provide a superior degree of separation between the sidewalk and street at reduced maintenance costs may be used.
Figure 18-49: Examples of landscaped tree wells
2. 
Design.
a. 
Shade trees should be planted to shade buildings’ east and west-facing windows to provide a balance between summer cooling and winter heating through solar gain.
b. 
All landscaped areas should be designed to allow aquifer filtration and minimize stormwater run-off utilizing bio-swales, filtration strips, and bio-retention ponds where appropriate.
(Ord. 2741 § 4 (part), 2024)
A. 
Purpose.
This section contains regulations and guidelines for the provision, design, and configuration of new open spaces that may be publicly accessible. Open space regulations are set forth to ensure that the provision, design, and configuration of new open spaces contribute to the character of and support the type of development desired within each District. Open space for residential uses is also intended to promote the health of residents by providing on-site open space for recreational activities, physical exercise, and/or food production. Open spaces may consist of pedestrian spaces for commercial uses, and common and private open space for residential uses.
B. 
All new open spaces, whether or not they are required by open space regulations, shall be designed and configured according to the following regulations.
C. 
The following requirements for the provision and design of pedestrian, common and private open spaces are organized by Use Type. These regulations are established to ensure a wide range of public spaces that complement the primary public streets and open spaces in each District as the Southcenter area intensifies.
D. 
General Open Space Regulations.
1. 
Open space requirements for commercial and residential uses are as specified in Table 18-4, “Provision of Open Space.”
2. 
Compliance with the open space square footage ratio listed in Table 18-4 is required for new construction, the area of expansion of existing buildings and changes in use from one category in Table 18-4 to another.
3. 
Open space for new or expanded commercial and residential uses shall be built within the development by developers at the time development occurs.
4. 
Options for Provision of Open Space.
a. 
The square footage of all streets built per TMC Section 18.28.140, “New Streets,” may be counted toward meeting the provision of open space requirements for pedestrian space. They may not be used to satisfy common and/or private open space requirements for residential uses.
b. 
The Director shall give credit for existing on-site open space amenities that meet the requirements of this section toward the open space square footage triggered by the new construction or change of use.
c. 
At the discretion of the Director, required pedestrian space for commercial uses or residential common open space may be constructed off-premises and/or as part of a larger open space being provided by the City or other private developments within that District or within 1,000 feet of the project premises.
d. 
If strict compliance with these regulations would create substantial practical difficulties for a site and none of the above approaches would provide relief, the property owner may apply for a Special Permission Modification and propose an alternate solution that meets the intent of the regulations.
(1) 
Special Permission Modification shall be a Type 2 decision. An applicant shall submit evidence of the above (subparagraph 18.28.250.D.4.d) to the Director, which could take the form of a brief report and site plan that addresses the difficulties of meeting the regulations, the proposed alternative solution, and how the proposed solution meets the intent of the applicable open space regulations.
(2) 
Applicants may request that up to 75 percent of their required pedestrian open space be provided indoors.
E. 
Pedestrian Space for Commercial Uses.
1. 
Pedestrian spaces for commercial uses are publicly accessible, outdoor, landscaped spaces used primarily for active or passive community recreation and civic purposes. These may include a linear green, square, plaza, courtyard, or pedestrian passage. Play areas for children may be provided indoors or outdoors. These spaces shall be privately owned and maintained, including keeping the space free of trash and graffiti. Amenities provided within the space, such as benches, planters, art and water features, shall be maintained for the life of the project.
2. 
Pedestrian Space Design Requirements.
a. 
Ground level pedestrian spaces shall be connected to public sidewalks and abut public rights-of-way on at least one side.
b. 
Ground level pedestrian spaces shall be located where they are visible and easily accessible to the public from adjacent sidewalks and avoid masses of shrubs around edges. The space shall not be more than 2 feet above or below the adjacent sidewalk.
c. 
Pedestrian spaces shall be comprised of a greater proportion of hardscape (paved areas, fountains, plants in pots), than softscape (grass or other landscape material). See Figure 18-50.
Figure 18-50: Examples of pedestrian spaces
d. 
Pedestrian spaces shall be publicly accessible during the hours of operation of the use. Pedestrian spaces, except for passages, shall be a minimum of 500 square feet or the required amount of open space (whichever is less) in size, contain seating areas, and open on to pedestrian generators such as entrances to offices, stores, or restaurants.
e. 
Pedestrian spaces shall be located to take advantage of sunlight to the greatest extent possible. South-facing plazas are generally preferred, unless particular lot configurations prevent such orientation.
f. 
At least 3 feet of seating area (bench, ledge, etc.) or one individual seat per 60 square feet of plaza area or open space shall be provided. This provision may be relaxed or waived where there are provisions for movable seating that meet the purpose of the standard. See Section 4 of the Southcenter Design Manual for guidelines on designing walls for seating.
g. 
Site design features that create entrapment areas in locations with pedestrian activity shall be avoided.
h. 
Development shall incorporate Crime Prevention Through Environmental Design (CPTED) principles into open space site design.
i. 
Pedestrian spaces shall not be located adjacent to dumpster enclosures, loading/service areas, or other incompatible uses unless fully screened with an architecturally consistent wall or solid fence (no chain link) and landscaping.
j. 
Pedestrian passage design requirements:
(1) 
A passage shall serve as a pedestrian connector passing between buildings to provide shortcuts through long blocks and access to rear parking areas or courtyards. (See Figure 18-51.)
Figure 8-51: Examples of pedestrian passages
(2) 
Passages shall be paved and landscaped, and specifically reserved for pedestrian travel.
(3) 
Passages shall be a minimum of 10 feet and a maximum of 30 feet wide.
(4) 
The design of the passage shall encourage pedestrian circulation. This can be accomplished by:
(a) 
Having the walkway meet the public sidewalk in an engaging and identifiable manner.
(b) 
Providing pedestrian amenities such as alternative paving methods, seating, and planters.
(c) 
Designing the passage using CPTED principles.
(5) 
Incorporate design treatments to mitigate impacts of any blank walls along the passageways (see Section 15 of the Southcenter Design Manual).
(6) 
For properties adjacent to fixed rail transit or bus facilities, a passage may include transit station or bus stop access.
(7) 
For properties adjacent to the Green River, a passage may include a pedestrian connection between the Green River Trail and a publicly accessible street/sidewalk. The passage should be established in an easement allowing for public access through private property.
F. 
Common Open Space for Residential Uses.
1. 
Purpose:
a. 
To provide accessible, safe, convenient, and usable common open space for residential uses;
b. 
To promote the health of residents by providing access to common open space for recreational activities, physical exercise, and/or food production; and
c. 
To create common open spaces that enhance the residential setting.
2. 
Common open spaces are privately owned and maintained interior common spaces, such as pools or exercise rooms, and/or outdoor landscaped spaces, such as rooftop decks, ground level open spaces, children’s play areas, or other multipurpose green spaces associated with multi-family developments that provide for the recreational needs of the residents of the development and are not publicly accessible.
3. 
Common open space design requirements (see Figure 18-52, and Section 5 of the Southcenter Design Manual, for additional guidance).
Figure 18-52: Common open space examples
a. 
Required building setback areas shall not be counted towards common open space.
b. 
No more than 50 percent of the required common space may be indoor or covered space.
c. 
Common open spaces shall be easily visible and readily accessible to multi-family residents.
d. 
The common open spaces for a site shall provide at least one of the following amenities for every 200 square feet of common open space up to a maximum requirement of three amenities to accommodate a variety of ages and activities:
(1) 
Site furnishings (tables, benches)
(2) 
Picnic and/or barbecue areas
(3) 
Patios, plazas, courtyards, or rooftop terraces
(4) 
Active play areas for children
(5) 
Urban (private/individual) garden plots
(6) 
Pool and/or hot tub
(7) 
Multi-purpose room with cooking facilities
(8) 
Exercise facility
e. 
Common open spaces shall not be less than 20 feet wide.
f. 
Courtyards shall be a minimum of 30 feet along the east-west axis and 20 feet along the north-south axis.
g. 
Adequate fencing, plant screening or other buffer shall separate the common open space area from parking areas, driveways, utility areas, mechanical equipment or public streets. Rooftop utilities shall be adequately screened and separated from rooftop common open spaces.
h. 
Common open spaces shall be located to take advantage of sunlight to the greatest extent possible.
i. 
Site design features that create entrapment areas in locations with pedestrian activity shall be avoided.
j. 
Development shall incorporate Crime Prevention Through Environmental Design (CPTED) principles into open space site design.
k. 
Common open spaces shall not be located adjacent to dumpster enclosures, loading/service areas, or other incompatible uses, unless fully screened with an architecturally consistent wall or solid fence (no chain link) and landscaping.
l. 
Interior located common space must be:
(1) 
Located in visible areas, such as near an entrance lobby and near high traffic corridors.
(2) 
Designed to provide visibility from interior pedestrian corridors and to the outside. Windows should generally occupy at least one-half of the perimeter of the space to make the space inviting and encourage use.
(3) 
Designed to specifically serve interior recreational functions and not merely leftover space used to meet the common space requirement.
m. 
Common open spaces shall be maintained by the property owner, including keeping the space free of trash and graffiti. Amenities provided within the space, such as benches, planters, art and water features, shall be maintained for the life of the project.
G. 
Private Open Space for Residential Uses.
1. 
Private open spaces are privately owned and maintained and include outdoor balconies, decks, patios, yards, courtyards, rooftop decks or gardens (Figure 18-53), or landscaped areas used for recreation by inhabitants of a single dwelling unit.
Figure 18-53: Rooftop Garden
2. 
Private open space design requirements.
a. 
Required setback areas shall not be counted towards private open space provision requirements, unless configured as a private yard and accessed by secondary unit entrance(s).
b. 
Private open spaces shall have primary access from the dwelling unit served.
c. 
Private yard landscaping shall be consistent with “Side and Rear Yard Landscape Types” (TMC Section 18.28.230.B).
d. 
Access to a balcony or patio shall be limited to the dwelling served.
(Ord. 2741 § 4 (part), 2024)
A. 
This section contains regulations and guidelines for the provision, locations, and design of parking. Parking regulations are set forth to ensure that the provision of parking, and the design and configuration of parking areas, contribute to the character of and support the type of development desired within each District in the urban center.
B. 
Number of Parking Spaces.
1. 
The minimum parking provision for vehicles required by all new development and changes in use shall be as specified in Table 18-5, “Provision of Parking.” In the case of a use not specifically mentioned in this table, the requirements for the number of off-street parking spaces shall be determined by the Director as a Type 2 Special Permission Decision. Such determination shall be based on the requirements for the most comparable use specified in this section or a parking study.
2. 
Any off-street parking area already in use or established hereafter shall not be reduced below the ratios required in Table 18-5. Any change of use must meet the parking requirements of the new use.
3. 
A maximum of 30% of the total off-street parking stalls may be designed and designated for compact cars.
4. 
Electric vehicle charging stations and parking spaces shall be governed by TMC Section 18.56.135.
5. 
Parking Reductions.
a. 
New on-street parking spaces provided along adjacent new streets may be counted toward the minimum parking requirement for commercial development on that property.
b. 
Parking requirements for commercial development within 600 feet of the Sounder transit station or the Tukwila bus Transit Center, or residential development within 1,320 feet of either station may be reduced or modified by the Director as a Type 2 Special Permission Decision. This distance will be the walking distance measured from the lot line of the development to the lot line of the station.
c. 
A reduction in minimum parking requirements may be requested per TMC Section 18.56.140, “Administrative Variance from Parking Standards.”
d. 
Shared Parking:
When two or more property owners agree to enter into a shared parking agreement, the setbacks and landscaping requirements on their common property line(s) may be waived with that land used for parking, driveway and/or building. The total number of spaces may be reduced if it is demonstrated through a parking study that complementary uses, internal trip capture or uses with different peak parking needs justify the reduction in number.
e. 
All or part of a development’s parking requirement may be satisfied through payment of in-lieu fees based on the current real cost of constructing a parking space in an exposed above-ground parking structure, when approved by the Director.
C. 
Vehicular Access.
1. 
Curb Cuts and Driveways.
a. 
When access to parking facilities and loading areas is provided from front or side streets, the maximum number of curb cuts associated with a single development shall be one two-lane curb cut or two one-lane curb cuts for each 500 linear feet of street frontage. Shared driveways and new public or private streets do not count against this total.
b. 
The maximum width of driveways/curb cuts is 15 feet for a one-lane and 30 feet for a two-lane driveway. In the Workplace District, the maximum width of driveways/curb cuts is 35 feet.
c. 
On Walkable and Neighborhood Corridors, the curb cut design for driveways or private streets shall match the height of the sidewalk to ensure that the sidewalk stays at a consistent grade for pedestrians, with the apron dipping down to meet the street level starting at the planting strip or tree wells (see Figure 18-54).
Figure 18-54: Example of driveway level with the height of the sidewalk
d. 
The total width of parking access openings on the ground level of structured parking may not exceed 30 feet when fronting on a public or private street.
e. 
Driveways shall be set back a minimum of five feet from adjoining properties (unless the driveway is shared with adjacent premises), and a minimum of three feet from adjacent buildings.
f. 
If two adjoining properties combine their side yards for the purposes of having a shared driveway, side yard landscaping requirements along that property line will be waived.
g. 
Driveways may not be signalized. In order to be considered for installation of a traffic signal, a new public or private street must be constructed per the standards in TMC Section 18.28.140.
h. 
These standards may be varied by the Director when there is a demonstrated conflict with truck maneuvering or fire access that cannot be addressed otherwise.
D. 
Parking Lots.
1. 
Dimensions.
Minimum parking area dimensions for surface parking shall be as provided in TMC Chapter 18.56, Figure 18-6, “Off-street Parking Area Dimensions.”
2. 
Maneuverability.
a. 
Adequate ingress to and egress from each parking space shall be provided without moving another vehicle and without backing more than 50 feet.
b. 
Tandem parking spaces (where one car is parked directly behind another) are allowed for residential units with two or more bedrooms and both spaces must be assigned for the exclusive use of that unit. All tandem parking spaces must be designed for full size rather than compact size vehicles based on the dimensions in TMC Chapter 18.56, Figure 18-6.
c. 
Turning and maneuvering space shall be located entirely on private property (Figure 18-55) unless specifically approved by the Public Works Director.
Figure 18-55. Not enough room on-site to exit loading area, resulting in disruption of traffic movements
d. 
The slope of off-street parking spaces shall not exceed 5%. The slope of entrance and exit driveways providing access for off-street parking areas and internal driveway aisles without parking stalls shall not exceed 15%.
3. 
Surface.
a. 
The surface of any required off-street parking or loading facility shall be paved with asphalt, concrete or other similar approved material(s) and shall be graded and drained as to dispose of all surface water, but not across sidewalks.
b. 
All traffic-control devices, such as parking stripes designating car stalls, directional arrows or signs, curbs and other developments shall be installed and completed as shown on the approved plans.
c. 
Paved parking areas shall use paint or similar devices to delineate car stalls and direction of traffic.
d. 
Wheel stops shall be required on the periphery of parking lots so cars will not protrude into the public right-of-way, walkways, off the parking lot or strike buildings. Wheel stops shall be two feet from the end of the stall of head-in parking.
4. 
Setbacks, Perimeter, and Interior Landscaping.
a. 
Surface parking lots shall set back a minimum of five feet from any back of sidewalk, open space, or building façade. The setback shall be designed and planted as specified in TMC Section 18.28.240.B.6.a.
b. 
See TMC Section 18.28.240.B.6.b for interior parking lot landscaping requirements.
5. 
Parking Lot Walkways.
a. 
A hard-surfaced walkway a minimum of 6 feet in unobstructed width shall be provided for safe walking areas through surface parking lots between main building entrances and sidewalks adjacent to streets. Front surface parking lots shall provide such routes at a maximum spacing of every 300 feet or to each major building entrance, whichever is closer.
b. 
Walkways through parking areas (see Figure 18-56) shall be separated from vehicular parking and travel lanes by use of contrasting paving material, curbing, or landscaping and may be raised above the vehicular pavement. Trees and pedestrian-scaled lighting (maximum 15 feet in height) shall be used to clearly define pedestrian walkways or other pedestrian areas within the parking area.
Figure 18-56: Parking lot walkway standards and example
c. 
Pedestrian crossings are required when a walkway crosses a paved area accessible to vehicles. Applicants must continue the sidewalk pattern and material across internal driveways.
6. 
Lighting and Safety.
Parking and loading areas shall include lighting capable of providing adequate illumination for security and safety, provide clear views both to and within the site, and be in scale with the height and use of the associated structure. See also TMC Section 18.28.280.B, “Lighting.”
E. 
Drive-Through Facilities.
1. 
Stacking lanes shall be located to the rear or least visible portion of a building.
2. 
Stacking lanes shall be designed to accommodate expected queuing.
F. 
Parking Structures.
1. 
Parking structures shall be located and designed to minimize their impact on public streets and public spaces. Consider using residential dwelling units, retail storefronts or office space to line the ground level façades of parking structures adjacent to a pedestrian-oriented street or open space.
2. 
Parking structures shall be buffered from adjacent residential development with heavy screening (see TMC Section 18.28.230.B.5, “Heavy Screening”).
3. 
See the Southcenter Design Manual (Section 16, “Parking Structures”) and the City of Tukwila’s “Parking Structure Design Guidelines” (2001) for additional requirements and guidelines regulating parking structures, parking podiums, and garages.
(Ord. 2741 § 4 (part), 2024)
A. 
Parking Lot Landscaping.
Note: See TMC Section 18.28.240.B.6 for standards for perimeter and interior parking lot landscaping.
1. 
Trees in parking areas, when mature, should be large and have a high-branching, broad-headed form to create maximum shade.
2. 
Landscaping in parking lot interiors and at entries should not obstruct a driver’s clear sight lines to oncoming traffic.
3. 
Rooftop Parking Landscape Alternatives.
a. 
Landscape Planters.
(1) 
For a parking area on the top level of a parking structure, one planter that is 30 inches deep and 5 feet square should be provided for every 10 parking stalls on the top level of the structure.
(2) 
Each planter should contain a small tree or large shrub suited to the size of the container and the specific site conditions, including desiccating winds.
(3) 
The planter should be clustered with other planters near driving ramps or stairways to maximize visual effect.
(4) 
Only non-flammable mulch such as gravel should be used.
b. 
Rooftop Garden or Green Roof.
An on-site rooftop area, equal in size to a minimum of 5 square feet of landscaping per each top level parking stall, may be covered with vegetation and soil, or a growing medium, planted over a waterproofing membrane.
c. 
Terraced Planters.
Upper levels of parking structures can be stepped back and incorporate irrigated terraced planters, equal in size to a minimum of 5 square feet of landscaping per each top level parking stall.
d. 
Green Wall.
The façade of the parking structure may be trellised and planted with vines or have an irrigated green wall system installed to provide a minimum of 5 square feet of landscaping per each top level parking stall.
B. 
Loading Zones.
Loading zones should be separated from customer and occupant pedestrian areas.
C. 
Bicycle Parking.
1. 
General Standards.
a. 
Racks should be oriented to maximize their efficiency and aligned to keep obstructions away from pedestrian thoroughfares.
b. 
Clustered arrangements of racks should be set back from walls or street furniture to allow bikes to be parked at both ends or from either side.
c. 
Where more than one rack is installed, the minimum separation between aisles should be 48 inches (the aisle is measured from tip to tip of bike tires across the space between racks). This provides enough space for one person to walk one bike. In high traffic areas where many users park or retrieve bikes at the same time, the recommended minimum aisle width is 72 inches.
d. 
Multiple buildings should be served by many small racks in convenient locations rather than a combined, distant rack area.
2. 
Short Term Parking.
a. 
Bicycle racks should be easy to find and located no more than 50 feet from the entrance of destinations. If bicycle parking is not easily visible from the street, a sign must be posted indicating its location.
b. 
Racks should be located within sight of gathering places or in busy pedestrian areas that provide constant, informal surveillance of bikes and accessories.
c. 
Building overhangs, canopies or other features should be used to provide weather protection.
3. 
Parking at the Workplace.
a. 
Secure bicycle storage areas should be used to park bikes for a full working day.
b. 
Bike storage areas should be located in high visibility areas close to elevators, stairs and entrances.
c. 
Bicycle parking should always be protected from the elements either indoors, covered by building elements, or in a separate shelter.
d. 
Bicycle storage areas should be located as close or closer to elevators or entrances than the closest car parking space, and no more than 200 feet from access points.
(Ord. 2741 § 4 (part), 2024)
A. 
Pedestrian Circulation.
Note: For walkways through parking lots, see TMC Section 18.28.260.D.5.
1. 
Redevelopment of a superblock site shall strive to create a pedestrian-friendly environment within the internal layout (see Figure 18-57). In addition to providing any required new streets, this can be accomplished by defining a network of pedestrian walkways that serve as a “grid”, connecting these walkways to uses with the site and to the larger street network, and creating smaller parking areas in place of one large parking lot.
Figure 18-57: Example of good internal pedestrian circulation. Note connections from the street, between buildings and through parking lots.
2. 
Pedestrian access points shall be provided along property edges at pedestrian arrival points and coordinated with crosswalks, transit stops, trails and paths, and existing and planned adjacent development.
3. 
Pedestrian paths must be provided across landscape areas, where needed, to allow convenient pedestrian circulation and prevent plants from being trampled and their roots compacted.
4. 
Walkways shall be provided along any building featuring a customer or residential entrance, and along any façade abutting a parking area (see Figure 18-58).
Figure 18-58: Internal walkway standards and an example along retail or mixed-use buildings
5. 
In the Regional Center, TOD, and Pond Districts, where a walkway crosses a driveway or a paved area accessible to vehicles, the crosswalk shall be distinguished by the use of durable low maintenance surface materials, such as pavers, bricks, or scored concrete, to enhance pedestrian safety and comfort, as well as the attractiveness of development. Pedestrian refuge islands and “speed tables” may also be used to minimize curb cuts and ramps (speed tables maintain the level of the adjacent sidewalk at identified pedestrian crossings, reversing the situation where a pedestrian must enter the zone of moving vehicles to cross the street). These pedestrian features shall be designed to accommodate fire lanes and emergency vehicle access routes.
6. 
The pedestrian marking style used shall be consistent throughout the development.
B. 
Lighting
(also see Section 3 of the Southcenter Design Manual).
1. 
Safety.
a. 
Pedestrian-oriented areas, including building entrances, walkways and paths, plazas, parking lots, and parking structures shall be illuminated to increase safety and provide clear views both to and within the site.
b. 
Pedestrian walkways where stairs, curbs, ramps, and crosswalks occur shall be lit for nighttime safety.
2. 
Glare Prevention.
a. 
Where appropriate, exterior lighting practices must follow the recommendations of the Illuminating Engineering Society of North America (IES).
b. 
New lighting fixtures shall be “dark sky” compliant, i.e. emitted light should be directed downward from the horizontal plane of the light source to preserve a dark sky and prevent unnecessary light pollution. Exceptions may be made for uplit trees and plants and exterior architectural lighting operated on timers to shut off after midnight nightly.
c. 
Where feasible, new fixtures shall use a reflector and/or a refractor system for efficient distribution of light and reduction of glare.
d. 
House-side shields and internal reflector caps shall be used to block light from illuminating residential windows.
3. 
Height.
a. 
The maximum mounting height for building-mounted lights is 20 feet above finished grade in Workplace and Corridor Commercial Districts and 14 feet above finished grade in all other Districts.
b. 
The maximum height for pole-mounted lighting at parking lots is 20 feet from grade to light source; lower heights should be used wherever possible.
c. 
The maximum height for pole-mounted lighting at pedestrian plazas, walkways, and entry areas is 12 to 14 feet in height from grade to light source.
C. 
Walls and Fences
(also see Section 4 of the Southcenter Design Manual).
1. 
All fences shall be placed on the interior side of any required perimeter landscaping.
2. 
Overall height of fences and walls located in the front yard shall not exceed 3 feet.
3. 
Barbed-wire, razor-wire, and corrugated metal fencing shall not be permitted. Chain link fencing is permitted only within the Workplace District.
4. 
Screening walls shall not exceed a height of 7 feet.
D. 
Utility and Service Areas
(also see Section 2 of the Southcenter Design Manual).
1. 
Service areas shall be appropriately screened. Garbage and recycling dumpsters visible from the public realm shall be screened from view using durable materials that complement the building, and incorporate landscaping integrated with other on-premises and adjacent landscaping. The opening to the service area shall be located away from the public sidewalk.
2. 
Utility and equipment cabinets shall be placed in less visible areas and screened, or located inside of a building.
3. 
Service equipment, including satellite receiving dishes, transformers, and backflow devices, shall be located away from streets and enclosed or screened from view by landscaping, fencing or other architectural means.
4. 
Screening of on-site mechanical equipment shall be integrated as part of a project’s site and building design and shall incorporate architectural styles, colors and other elements from the roof and façade composition to carefully integrate screening features. Picket fencing, chain-link fencing and exposed sheet metal boxes are not permitted outside of the Workplace District.
(Ord. 2741 § 4 (part), 2024)