A. 
This district implements the High-Density Residential (HDR) Comprehensive Plan designation. It is intended to provide a high-density, multiple-family district which is also compatible with commercial and office areas.
(Ord. 2741 § 4 (part), 2024; Ord. 2765 § 13, 2025; Ord. 2770, 10/20/2025)
A. 
Refer to TMC Chapter 18.09, “Land Uses Allowed by District.” Parcels within a Commercial Redevelopment Area may be permitted to aggregate with, and use the development standards and permitted uses of, any adjacent parcel within the NCC or RC zoning district, pursuant to TMC Section 18.60.100
(Ord. 2741 § 4 (part), 2024; Ord. 2770, 10/20/2025)
A. 
In the HDR zoning district, any proposed multiple-family structure, complex or development shall provide, on the premises and for the use of the occupants, a minimum amount of recreation space according to the provisions of TMC Section 18.14.030, subparagraphs 1 through 4. In the TSO zone with underlying CR zoning on land that adjoins the City of SeaTac, recreation space shall meet the provisions of TMC Section 18.14.030, subparagraphs 2 through 4, in addition to the minimum required area as specified in TMC Section 18.41.090.A.1.
1. 
Required Area.
a. 
For each proposed dwelling unit in the multiple-family development and detached zero-lot-line type of development, a minimum of 400 square feet (100 square feet for senior citizen housing) of recreation space shall be provided. Any multiple-family development shall provide a minimum of 1,000 square feet of total recreation space.
b. 
The front, side and rear yard setback areas required by the applicable zoning district shall not qualify as recreation space. However, these setback areas can qualify as recreation space for townhouses if they are incorporated into private open space with a minimum dimension of 10 feet on all sides.
2. 
Indoor or Covered Space.
a. 
No more than 50% of the required recreation space may be indoor or covered space in standard multi-family developments. Senior citizen housing must have at least 20% indoor or covered space.
b. 
The Director may grant a maximum of two square feet of recreation space for each one square foot of extensively improved indoor recreation space provided. Interior facility improvements would include a full range of weight machines, sauna, hot tub, large screen television and the like.
3. 
Uncovered Space.
a. 
A minimum of 50% of the total required recreation space shall be open or uncovered; up to 100% of the total requirement may be in open or uncovered recreation space in standard multi-family developments. Senior citizen housing allows up to 80% of recreation space to be outdoors and has no minimum outdoor space requirement.
b. 
Recreation space shall not exceed a 4% slope in any direction unless it is determined that the proposed space design clearly facilitates and encourages the anticipated.
c. 
The Director may grant a maximum credit of two square feet of recreation space for each one square foot of outdoor pool and surrounding deck area.
4. 
General Requirements.
a. 
Multiple-family complexes (except senior citizen housing, and detached zero-lot-line), which provide dwelling units with two or more bedrooms, shall provide adequate recreation space for children with at least one space for the 5- to 12-year-old group. Such space shall be at least 25% but not more than 50% of the total recreation space required under TMC Section 18.14.030 (1), and shall be designated, located and maintained in a safe condition.
b. 
Adequate fencing, plant screening or other buffer shall separate the recreation space from parking areas, driveways or public streets.
c. 
The anticipated use of all required recreation areas shall be specified and designed to clearly accommodate that use.
(Ord. 2741 § 4 (part), 2024; Ord. 2765 § 14, 2025)
A. 
Development within the High-Density Residential District shall conform to the following listed and referenced standards:
HDR BASIC DEVELOPMENT STANDARDS
Lot area, minimum
8,000 sq. ft. (Applied to parent lot for townhouse subdivisions)
Lot area per unit (multi-family, except senior citizen housing)
2,000 sq. ft. (For townhouses the density shall be calculated based on one dwelling unit per 2000 sq. ft. of parent lot area. The “unit lot” area shall be allowed to include the common access easements.)
Average lot width (min. 20 ft. street frontage width), minimum
60 feet (Applied to parent lot for townhouse subdivisions)
Setbacks, minimum:
Applied to parent lot for townhouse subdivisions
Front
15 feet
Second front
7.5 feet
Sides
10 feet
Rear
10 feet
Refer to TMC Ch. 18.52, “Landscape Requirements,” Table A, for perimeter and parking lot landscaping requirements.
Townhouse building separation, minimum
10 feet
Height, maximum
45 feet
Development area coverage
50% maximum (except senior citizen housing), (75% for townhouses)
Recreation space
400 sq. ft. per dwelling unit (1,000 sq. ft. min.)
(Not required for middle housing dwellings)
Recreation space, senior citizen housing
100 sq. ft. per dwelling unit
Off-street parking
See TMC Ch. 18.56, Off-street Parking & Loading Regulations & Figure 18-7 – Required Number of Parking Spaces for Automobiles & Bicycles
Conversion to Residential
See TMC § 18.50.230, Residential Conversions
(Ord. 2741 § 4 (part), 2024; Ord. 2758 § 3, 2025; Ord. 2765 § 16, 2025)