A. 
This district implements the Tukwila South Master Plan designation and related policies and provisions of the Tukwila Comprehensive Plan. As an overlay district, the Tukwila South Overlay (TSO) district may be applied by the City Council to any property lying within the Comprehensive Plan's Tukwila South Master Plan Area. Within the Tukwila South Overlay, the provisions of this chapter shall supersede the provisions of the underlying zoning district.
B. 
The Tukwila South Overlay district is intended to create a multi-use regional employment center containing high technology, office, commercial, and residential uses. National and international employers specializing in emerging technologies (bio-tech/life sciences) are featured in campus settings. Retail activities range from individual large-scale national retailers to gateway and village retail and shopping centers that support office and high-tech campuses and residential neighborhoods. A mix of single-family and multi-family dwellings at low, medium, and high densities provide a variety of housing opportunities. Tukwila South will create a memorable and regionally identifiable place by building upon the Northwest tradition of quality outdoor environments and quality building materials, combined with traditional Puget Sound building elements.
(Ord. 2741 § 4 (part), 2024)
A. 
No on-site hazardous substance processing and handling or hazardous waste treatment and storage facilities shall be permitted, unless clearly incidental and secondary to a permitted use. On-site hazardous waste treatment and storage facilities shall be subject to the State siting criteria (RCW 70.105). (See TMC Chapter 21.08.)
(Ord. 2741 § 4 (part), 2024)
A. 
The Director shall require that all development within the Tukwila South Overlay district is consistent with the policies of the Tukwila Comprehensive Land Use Plan and the Tukwila South Master Plan, and conforms to the requirements of this title and any applicable development agreement.
B. 
Design review is required for all non-exempt development within the Tukwila South Overlay district. The applicant may submit a site plan for review for all or a portion of the area covered by the Tukwila South Master Plan. Prospective applicants are encouraged to schedule a pre-application conference as provided by TMC Section 18.104.050 prior to submitting a design review application.
C. 
The following development activities are exempt from design review:
1. 
Interior remodeling of existing buildings or structures.
2. 
Underground utility projects.
3. 
Detached single-family subdivisions subject to TMC Title 17 – Subdivisions and Plats.
4. 
Exterior repair, reconstruction, cosmetic alterations or improvements if the cost of that work is less than 10% of the building's assessed valuation.
5. 
Development that is categorically exempt under the State Environmental Policy Act (SEPA) (RCW 43.21C).
D. 
Design review includes an examination of the following elements: placement and scale of structures, design, height, form, parking, access, signage, vehicular and pedestrian connections and circulation, environmental considerations, open space, landscaping, and infrastructure needs as described in the Tukwila South Master Plan or any applicable development agreement.
The purposes of the review process include:
1. 
Allowing City staff to review the detailed arrangement of the proposed development to ensure it is consistent with the intent and scope of the Tukwila South Master Plan, as well as any applicable development regulations, zoning district provisions, design review standards, and any approved development agreement provisions.
2. 
Assure the proposed development is compatible with both the physical characteristics of the site, and the existing and potential uses of the surrounding area as described in an approved Master Plan.
3. 
Ensure compliance with the requirements of the State Environmental Policy Act (SEPA - RCW 43.21C) and other applicable regulations and standards.
E. 
All design review applications for development within the Tukwila South Overlay district shall be reviewed in accordance with the following criteria. When two or more of the criteria listed below conflict, the Director shall evaluate the applicability and importance of each based on the intent of the Tukwila South Master Plan and reasonably balance any conflicting criteria in reaching a design review decision.
1. 
Substantial conformance with the Tukwila South Master Plan, including but not limited to, fostering the vision and guiding principles of the Master Plan.
2. 
Compliance with the applicable district standards in this title, and other applicable City regulations. Modifications to the development standards may be requested as part of design review per TMC Section 18.41.100.
3. 
Substantial consistency with Tukwila Comprehensive Land Use Plan goals and policies.
4. 
Substantial conformance with the provisions of any applicable development agreement.
5. 
Substantial conformance with all applicable mitigation measures identified in the associated EIS or other SEPA documents.
6. 
Adequate public services and facilities necessary to accommodate the proposed use and density are or will be made available.
7. 
The site is physically suitable for the type of development and for the intensity of development proposed.
8. 
Approval of the application will not be significantly detrimental to the public health, safety or welfare, or be injurious to the property or improvements of adjacent properties and public facilities.
9. 
Substantial conformance with the criteria contained in the Tukwila South Design Manual for commercial development, the Tukwila South Residential Design Guidelines, or other Design Manual as stipulated by TMC Chapter 18.60.
10. 
Substantial conformance with the Master Open Space and Trails Plan, if applicable.
F. 
Upon completion of the City's review, the Director shall approve, approve with conditions or deny the application, as follows:
1. 
If the Director finds the application meets the applicable criteria and is consistent with the approved Master Plan for that area of the Tukwila South Overlay district, the Director shall approve the proposal.
2. 
Approve with Conditions: If the Director finds the application does not adequately address one or more of the applicable criteria, but is consistent with the approved Master Plan for the Tukwila South Overlay district, and there is a reasonable basis for conditions, the Director may approve the application with conditions. The intent of such conditions is that they mitigate an impact consistent with the intent of the applicable criterion. Conditions of approval may include, but are not necessarily limited to, the relocation or modification of the proposed structures, additional landscaping, buffering, screening, relocation of access, or other measures necessary to mitigate any impact or reduce hazards. The Director shall specify when the conditions shall be met.
3. 
Denial: If the Director finds the application does not meet applicable criteria and reasonable conditions cannot be found to mitigate the impact or reduce hazards, the Director shall deny the application as proposed. The Director’s decision must specify the reasons for the denial based upon the review criteria.
(Ord. 2741 § 4 (part), 2024)
A. 
Residential Uses.
1. 
Residential use development on all lands within the TSO shall conform to the development standards set forth in TMC Section 18.41.090.A and the Tukwila South Residential Design Guidelines. Modifications to these standards are available pursuant to TMC Section 18.41.100, “Modifications to Development Standards through Design Review.”
2. 
The development standards herein are based on the height of new residential buildings. Specifically:
a. 
Buildings three stories or less are subject to townhouse and low-rise standards.
b. 
Buildings between four to seven stories are subject to mid-rise standards.
c. 
Buildings eight stories or taller are subject to high-rise standards.
d. 
For buildings with a varying number of stories, the tallest number of stories shall determine which set of standards apply.
Table 18.41.090
Tukwila South Overlay Residential Development Standards
Standard
TSO
Townhouses & Low-rise
(3 stories or less)
TSO
Mid-rise
(4-7 stories)
TSO
High-rise
(8 or more stories)
Setbacks/yards, minimum (feet)
Front1
Arterial streets
15
15
15
All other streets
10
10
10
Side2
Up to 3rd story
5
53
53
4th story and above
n/a
154
154
Rear3
Up to 3rd story
5
53
53
4th story and above
n/a
154
154
Building height, maximum (feet)
Building Height
45
85
125
Outdoor lighting height, maximum (feet)
Light poles in parking areas
20
20
20
Light poles along pedestrian walkways, trails, plazas, building entries, and other pedestrian-oriented areas
12
12
12
Building wall-mounted lighting
15
15
15
Building mounted lights fully recessed into the underside of a ceiling, soffit, or overhang
No limit
No limit
No limit
Building length, maximum (feet)
Maximum building length
200
200
200
Recreation space per unit, minimum square footage (see TMC § 18.41.090.3 for more information)7,8
Recreation space
Residential development must provide on-site9 and off-site10 recreation space at the following standard:
• 200 square feet total.
o 75 square feet per unit, on-site.
o 125 square feet per unit, off-site.
Parking spaces per dwelling unit, minimum
Studio
1
1
1
1-bedroom
1
1
1
2-bedroom
1.5
1.5
1.5
3-bedroom
2
2
2
Conversion to Residential
See TMC § 18.50.230, Residential Conversions
Notes:
1
In the event modification is pursued under TMC § 18.41.100, front setbacks may be reduced to no less than 5 feet.
2
Structures or portions of structures containing multi-family dwelling units that have solar access only from a side or rear setback-facing window(s) must be set back at least 15 feet from side and rear property lines. Structures must also maintain at least 15 feet of separation from adjacent structure elevations that provide the only solar access for a multi-family dwelling unit. See the Tukwila South Residential Guidelines for a graphic example.
3
When adjacent to a townhouse, the minimum setback is 15 feet.
4
When adjacent to a townhouse, the setback for portions of a structure taller than 35 feet must increase by 1 foot for each additional 1 foot in building height.
5
(no note)
6
(no note)
7
Senior citizen housing must provide 100 square feet of recreation space per unit.
8
Developments with 10 or more dwelling units must provide a children’s play area in the on-site recreation space. A children’s play area is not required for senior citizen housing or if the proposed structure or related development project is within 1/4 mile, measured along constructed sidewalks and/or trails of the perimeter, of a recreation facility for children that is open to residents of the proposed structure.
9
Recreation area provided on-site must be functional space for active and passive recreation purposes and located within the same parcel or tract as the proposed development.
10
The Director may approve the required off-site recreation area to be located on-site provided that the recreation space meets the design guidelines set forth in this chapter. If off-site recreation space is approved to be located on-site, that space must be active outdoor recreation space.
3. 
Off-Site Recreational Area Requirements.
The following requirements would apply to Off-Site Recreational Areas within the TSO district:
a. 
Off-Site Recreational Area Conditions:
(1) 
Off-site recreation areas must be accessible within 1/4 mile for a children’s play area up to 1/2 mile for all other offsite recreation areas as measured from the closest structure containing residential units; accessory buildings such as fitness centers, parking garages, utility structures, etc. will not qualify. Off-site recreation space located up to 1 mile from a structure containing residential units as measured along existing or future sidewalks and trails shall be credited toward meeting the offsite recreation space requirement.
(2) 
A recreation area constructed in fulfilment of this requirement should be designed to serve the neighborhood in which it is located. The space may be privately-owned, provided residents living in the area have access. New improvements must be located adjacent to, and highly visible from, a street (public or private) or public trail. The facilities to be located will be approved by the Director during the design review and/or subdivision process.
b. 
Minimum Off-Site Recreational Area Design:
Minimum size requirements apply: 1/ 4 acre of usable off-site recreation space must be provided to meet the standard. This qualifies as the minimum size for an off-site recreation area. Off-site recreational areas must be designed and sized to accommodate a combination of active and passive recreational facilities.
Examples of qualifying facilities:
(1) 
Children’s play equipment.
(2) 
Picnic areas and/or tables.
(3) 
Benches.
(4) 
Pea patch/other specialized community garden.
(5) 
Grass fields/areas of suitable size for active recreation.
(6) 
Sport courts.
(7) 
Trails and associated landscaped corridors on private property.
(8) 
Other amenities the Director determines meet the goal of providing active or passive recreation opportunities.
c. 
Larger Off-Site Recreational Areas:
(1) 
Any offsite recreation area developed in excess of the offsite recreation area requirement for a given development, regardless of their size and subject to the 1/4-acre size minimum, may be banked toward future development for an indefinite period.
(2) 
Should a larger, consolidated recreation area of 2.0 acres or more be provided, the improvements can be used to fulfill current development proposal requirements. See “Timing of Recreation Space Provision” below for more information.
(3) 
If a project constructs a recreation area of less than 2.0 acres but greater than a development’s required offsite recreation amount, the area developed in excess may be banked only if the offsite recreation area is constructed at the same time as the residential project.
(4) 
To qualify, the proposed recreation area must be located adjacent to, and highly visible from, a street (public or private) or trail and provide a range of active and passive recreational opportunities (as outlined in this Chapter) for multiple ages and physical abilities. Only those areas that are usable may count towards the off-site recreation space requirement. The following areas are excluded: parking lots, utility sheds, inaccessible natural/planted areas, any landscaped area required by code, and unimproved steep slopes as defined in TMC Section 18.45.120.
(5) 
Larger off-site recreational areas are typically characterized by recreational activities that serve a range of individuals and groups, such as field games, court games, craft areas, playground apparatus, picnicking, and space for quiet/passive activities. Neighborhood recreation areas may contain active recreational facilities such as softball, basketball, volleyball, handball, tennis, children’s play structures, trails, and grass areas for activities and/or picnic facilities.
d. 
Timing of Recreation Space Provision:
Construction of off-site recreation space must meet the following timelines.
(1) 
For sites under 2.0 acres in area, the off-site recreation space must be constructed and receive final construction permit approval prior to the issuance of certificate of occupancies for any project receiving credit for the off-site recreation space.
(2) 
For sites equal to or in excess of 2.0 acres, the City will permit delayed construction of the off-site recreation space as follows:
(a) 
Construction permits must be applied for within two years of the associated residential project(s) using such off-site recreation space to satisfy their recreation space requirement and receiving certificate(s) of occupancy. Provided:
i. 
A financial guarantee (bond, assignment of account, irrevocable standby letter of credit, or cash), acceptable to the Director, in an amount necessary to complete the off-site recreation improvements is provided to the City.
ii. 
The owner of the property for the off-site recreation area has provided an appropriate legal mechanism acceptable to the City to access the identified off-site recreation area, such as an easement, at no cost, and to construct the off-site recreation space improvements in the event that the applicant and/or property owner have not completed the improvements within the prescribed timelines.
iii. 
The requirements in TMC Section 18.41.090.A.3.d.(a).i and ii are not required if the permits for off-site recreation space have received final approval by the City.
(3) 
No additional residential projects within the 1/2 mile radius of the deferred off-site recreation area will be allowed to move forward with construction until such off-site recreation space construction has been completed.
(4) 
Construction of the off-site recreation improvements must be completed within a timely manner from permit approvals. If adequate provisions, as determined by the Director, cannot be put in place to ensure the future construction of the off-site recreation space, then the space shall be constructed prior to the issuance of any certificate of occupancy for any developments using the off-site area to meet recreational space requirements.
e. 
Sensitive Area Tracts:
Off-site recreation space credit can be given for any trails, lookouts, or other passive recreation activities constructed within sensitive area tracts, subject to compliance with the City’s Sensitive Area Master Plan for Tukwila South and the City’s Environmental Areas Ordinance. The sensitive areas tracts would need to meet the locational requirements outlined in this Chapter (1/2 mile from closest perimeter of a residential project). Only the areas of improvement within a sensitive area tract would count towards the recreation space requirement, not the entire tract.
4. 
Performance Standards:
Use, activity, and operations within a structure or a site shall comply with: (1) standards adopted by the Puget Sound Air Pollution Control Agency for odor, dust, smoke and other airborne pollutants; (2) TMC Chapter 8.22, “Noise”; and (3) adopted State and Federal standards for water quality and hazardous materials. In addition, all development subject to the requirements of the State Environmental Policy Act, RCW 43.21C, shall be evaluated to determine whether adverse environmental impacts have been adequately mitigated.
B. 
Connectivity and Circulation Guidelines.
1. 
Any development with a residential component shall front a roadway that meets City approved public or private street standards.
2. 
Access to development sites needs to include provisions for non-motorized circulation, including dedicated pedestrian access that separates pedestrians from motorized traffic via curb and/or landscaped planter strip. Development along public rights-of-way should not preclude bus stops and bike infrastructure. Private street development, contained within tracts or easements, may be required to include shared and/or dedicated bike lanes, on-street parking, and/or drop-off/loading zones.
3. 
Existing curb cuts from Southcenter Parkway and South 200th Street are to be used for access to the adjacent development sites and to extend private streets, contained within tracts or easements. If no curb cut exists along an existing road fronting a development site, City of Tukwila Public Works may review and approve new curb cut location(s) along such street frontage, subject to intersection spacing and site distance standards.
4. 
New streets are encouraged to connect to adjacent parcels at an interval no greater than 700 feet. Where nearby parcels and associated private streets have already been developed, proposed private streets, whether in tracts or easements, shall align and connect.
5. 
Future block development is encouraged to create a maximum block perimeter 2,000 linear feet. The block will be defined with a minimum of two vehicle through connections. The remaining two sides of the block may be pedestrian/bicycle connections only or could accommodate vehicle traffic; see example below.
6. 
Permanent dead-end streets should be avoided, if possible.
7. 
All developments must meet minimum Fire Department and Public Works Department access and grade requirements including, but not limited to, minimum street clearance, turning radii, and turnaround design.
8. 
The Director may provide exceptions to these guidelines in the event they are unable to be adhered to due to physical/topographical constraints, the creation of an unusable parcel(s) of land, or an inability to fulfill the requirements without significantly interfering with the proposed function(s) of the development given that the overall intent of the guidelines is still fulfilled.
BLOCK EXAMPLE:
C. 
Non-Residential Uses.
All non-residential use development on all lands within the TSO shall conform to the development standards set forth in TMC Section 18.41.090.C. Modifications to these standards are available pursuant to TMC Section 18.41.100, “Modifications to Development Standards through Design Review.”
Lot
N/A
Setbacks:
Front – adjacent to a public street
15 feet*
Second Front – adjacent to a public street
15 feet*
Sides
None*; increased to 10 feet if adjacent to residential use or non-TSO zoned property
Rear
None*; increased to 10 feet if adjacent to residential use or non-TSO zoned property
Height
125 feet
Landscaping:
Fronts – adjacent to a public street
15 feet
Side
None; increased to 10 feet if adjacent to residential use or non-TSO zoned property
Rear
None; increased to 10 feet if adjacent to residential use or non-TSO zoned property
Landscape requirements (minimum): See Landscape, Recreation, Recycling/Solid Waste Space requirements chapter for requirements
Off-street parking:
See TMC Ch. 18.56
Notes:
*Subject to modification to meet Fire Department Access Requirements
(Ord. 2741 § 4 (part), 2024; Ord. 2758 § 10, 2025)
A. 
An applicant may request a modification to the Basic Development Standards established by TMC Section 18.41.090 as part of a design review application. The applicant shall submit a written description of the proposed modification and address the decision criteria stated in TMC Section 18.41.100.B; the Director may condition the approval of a modification request when such conditions are necessary to achieve conformity with these decision criteria.
B. 
The Director may grant modifications to the Basic Development Standards established by TMC Section 18.41.090 for individual cases provided that, for development of a residential use, the Director shall find that either the modification is allowed because it results in a more thoughtful urban design for the project consistent with the Tukwila South Residential Design Guidelines, or that all five criteria below are met and, for development of a non-residential use, the Director shall find that all five criteria below are met:
1. 
The modification is required due to unique circumstances related to the subject property that create significant practical difficulties for development and use otherwise allowed by this code;
2. 
The modification conforms to the intent and purpose of the Tukwila South Master Plan, any applicable development agreements, and this code;
3. 
The modification will not be injurious to other property(s) in the vicinity;
4. 
The modification will not compromise the current or reasonably anticipated provision of circulation, access, utility service or any other public service; and
5. 
An approved modification shall be the minimum necessary to ameliorate the identified practical difficulties giving rise to the request.
(Ord. 2741 § 4 (part), 2024)
A. 
Within 90 days of the approval by the Director, final plans shall be prepared and filed with the City. These plans shall include all required modifications and applicable conditions contained in the Director’s Notice of Decision.
B. 
The final plans are not required to be recorded unless there is an associated land division application, such as a binding site plan or subdivision.
(Ord. 2741 § 4 (part), 2024)
A. 
The Building Official may not issue a Certificate of Occupancy until all improvements included in the approved plans have been installed and approved, with the following exceptions:
1. 
A performance guarantee has been posted for the improvements not yet completed.
2. 
The phasing of improvements has been accounted for in an associated Binding Site Plan, infrastructure phasing agreement, a condition of approval, or a development agreement.
(Ord. 2741 § 4 (part), 2024)