Chapter 19.46
CLUSTER SUBDIVISIONS
Sections:
19.46.010 Purpose of cluster development provisions.
19.46.020 Applicability of cluster development.
19.46.040 Development standards for cluster developments.
19.46.050 Alternative to cluster subdivision provisions.
19.46.060 Additional development provisions.
19.46.010 Purpose of cluster development provisions.
A. Much of the land designated by the Sultan comprehensive plan for residential development is not developable because of extensive wetlands and steep slopes that are protected by critical area regulations. Exclusion of these critical areas results in a net developable area that allows considerably fewer residential units than would be allowed if the entire property could be developed at standard zoning densities. The city finds that cluster subdivision is an appropriate regulatory approach to protect critical areas.
B. Cluster subdivision is an approach to dividing land that allows a parcel to be divided such that some or all of the resulting lots are smaller than the minimum lot size required in the applicable zone to accommodate the presence of extensive wetlands, critical areas, or allow for flexibility when working with an irregular parcel.
C. The number of lots resulting from development cannot exceed the maximum density of the underlying zoning district, unless otherwise specified in this chapter.
D. Cluster subdivision does not assure that the density available to a developer on a particular parcel will be the same as the density available if the property were not encumbered by critical area exclusions. It is provided as a mechanism to achieve full compliance with all critical area regulations while allowing the development densities to get closer to the allowed zoned density on properties that have significant critical areas exclusions. (Ord. 1353-21 § 3 (Att. B))
19.46.020 Applicability of cluster development.
A. Cluster subdivision provisions of this chapter apply to and may be used by developers of land who are dividing land in conformance with the provisions of this chapter, and who meet the provisions set out in subsections (B) and (C) of this section.
B. Cluster subdivision provisions of this chapter apply to and may be used by developers of land in the following zones:
1. Low/moderate density, LDR (SMC 16.12.010).
2. Moderate density, MDR (SMC 16.12.020).
3. High density, HDR (SMC 16.12.030).
C. Cluster subdivisions may be used if they result in a development that contains single-family detached dwellings, duplexes, zero lot line dwellings, or townhomes. Attached units must be contained with their own individual lot. (Ord. 1353-21 § 3 (Att. B))
19.46.030 Review process.
A. Cluster subdivision provisions of this chapter shall adhere to all subdivision procedures set forth in Chapter 19.08 SMC, unless otherwise outlined in this chapter. (Ord. 1353-21 § 3 (Att. B))
19.46.040 Development standards for cluster developments.
A. Dimensional Standards Modification. The dimensional standards set forth in Chapter 16.12 SMC are modified as follows for sites processed through the cluster subdivision process. All other dimensional standards of Chapter 16.12 SMC shall apply, including applicable conditions.
|
|
Minimum Lot Dimensions |
Minimum Yard Setbacks (ft)1,2,3 |
|
||||
|---|---|---|---|---|---|---|---|
|
Zone/Use Permitted |
Area |
Width (ft) |
Depth (ft) |
Front |
Each Side |
Rear |
Max. Lot Coverage (%) |
|
Low Density Residential (LDR) |
|||||||
|
Single-Family Detached Dwellings |
4,500 sq. ft. |
50 |
70 |
15 |
5 |
10 |
55 |
|
Moderate Density Residential (MDR) |
|||||||
|
Duplexes/Two-Family Dwellings |
6,000 sq. ft. |
50 |
60 |
15 |
5 |
10 |
65 |
|
Zero Lot Line Dwellings4 |
3,000 sq. ft. |
40 |
60 |
15 |
105 |
10 |
65 |
|
Single-Family Detached Dwellings |
2,700 sq. ft. |
40 |
60 |
15 |
5 |
10 |
65 |
|
High Density Residential (HDR) |
|||||||
|
Duplexes/Two-Family Dwellings |
3,600 sq. ft. |
40 |
60 |
15 |
5 |
10 |
65 |
|
Townhouse |
2,200 sq. ft. |
40 |
60 |
0 |
56 |
10 |
65 |
|
Single-Family Detached Dwellings |
2,200 sq. ft. |
40 |
60 |
15 |
5 |
10 |
65 |
1. All site and development plans within short and formal subdivisions shall show building envelopes based on minimum yard setbacks.
2. Eaves of a dwelling or accessory structure may project 18 inches from the line of the setback toward a property line when the setback is at least five feet, and 16 inches toward a property line when the setback is at least six feet. All other uses shall conform to the requirements of the International Building Code Sections 503.2 and 705.
3. All yards adjacent to public rights-of-way shall be considered front yards. In the case of a “corner lot” with two front yards, one front yard will be designated for only half the front yard setback requirements, depending on principal building or lot access or narrowest width of the lot as determined by the zoning administrator. In the case of a “through lot” with two front yards, both front yards shall have front yard setback requirements.
4. See SMC 16.04.260(2) for definition of “zero lot line dwelling.”
5. For the side yard not utilized as the joint side yard, the minimum setback shall be 10 feet.
6. See SMC 16.04.200(12) for definition of “townhouse.”
B. Perimeter Setbacks. At a minimum, structures shall comply with the setbacks of the underlying zone along all perimeter lot lines of the overall site.
C. Maximum Density.
1. The maximum density shall be calculated by multiplying the gross site area (in acres) by the maximum units/acre in the applicable zone as shown here:
|
Zone |
Maximum Units/Acre |
|---|---|
|
Low Density Residential (LDR) |
5 |
|
Moderate Density Residential (MDR) |
10 |
|
High Density Residential (HDR) |
12 |
2. When the density calculation results in a fraction, the fraction shall be rounded to the nearest whole number as follows:
a. Fractions of 0.50 and above are rounded up.
b. Fractions below 0.50 are rounded down.
3. Density Bonus for Development Sites With Critical Areas. If 10 percent or more of a site’s gross area contains critical areas, as defined within Chapter 17.10 SMC, an increase of up to 15 percent of the calculated density shall be allowed; provided at least 20 percent of the gross site area is contained within an open space tract consistent with the standards set forth in this chapter.
D. Recreational and Open Space Requirement.
1. All cluster subdivisions shall comply with the recreational and open space standards as outlined in Chapter 16.62 SMC with the following exceptions:
a. No cluster subdivision may use the exemption detailed in SMC 16.62.060 regardless of the number of lots being created.
b. No cluster subdivision may pay a fee in lieu of on-site recreation improvements as detailed in SMC 16.62.070.
c. One additional recreational facility must be provided beyond the minimum requirement listed in Table 16.62-A. For example, a cluster subdivision containing 11 to 20 units must provide a minimum of two recreational facilities.
d. Instead of the five percent of the total land area of a subdivision that must be dedicated as open space beyond the recreational facilities requirement that is stated in SMC 16.62.060, at least 10 percent of the total land area of a cluster subdivision shall be dedicated as open space tracts (or parcels of land). If the applicant wishes to take advantage of the density bonus for development sites with critical areas that is described in subsection (C)(3) of this section, at least 20 percent of the total land area of the cluster subdivision shall be dedicated as open space tracts (or parcels of land).
e. Any open space tracts shall provide a minimum dimension of 15 feet. (Ord. 1353-21 § 3 (Att. B))
19.46.050 Alternative to cluster subdivision provisions.
A. Lots may be exempted from the minimum lot area, depth, width, and rear setback standards set forth in SMC 19.46.040, provided they are arranged in clusters of four to 12 dwelling units around a centralized common open space under the following provisions:
1. Cluster single-family developments shall meet underlying zoning district density standards.
2. All standard street and access setbacks shall still apply.
3. There shall be 10 feet minimum building separation for detached dwellings.
4. Minimum off-street parking standards shall comply with SMC 16.54.140, unless otherwise specified in this chapter.
5. One parking stall shall be provided on each proposed lot with adequate vehicular access.
6. Guest Parking. Off-street guest parking shall be provided at a rate of one space for every four dwelling units. Guest parking shall be located in clusters of not more than five adjoining spaces.
a. Guest parking shall be located on the development site.
b. Guest parking areas are prohibited within 40 feet of a public street.
7. Recreation Areas and Open Space. Recreation areas and open space shall be provided as outlined in Chapter 16.62 SMC and meet the following additional requirements:
a. A common open space, recreational area, or combination open space and recreational area is required for each cluster of four to 12 dwellings.
b. Each common open space, recreational area, or combination open space and recreational area shall be a minimum of 1,500 square feet in size with no dimension less than 15 feet, regardless of the number of dwelling units.
c. All dwellings in the cluster must abut the common space. Direct access to the common space shall be provided for each dwelling by a paved walkway. (Ord. 1353-21 § 3 (Att. B))
19.46.060 Additional development provisions.
A. Road standards required for development of land divisions by this title are required in developments without regard to their implementation of cluster subdivision standards of this chapter.
B. All standard utility improvements required for land divisions by this title are required in developments without regard to their implementation of cluster subdivision standards of this chapter.
C. All standards for lot layout, setbacks, access, easements, and any other development standards for individual lots required for land divisions by this chapter are required in developments without regard to their implementation of cluster subdivision standards of this chapter, unless otherwise explicitly stated in this chapter.
D. Modification of specific development standards as provided by this chapter may be applied for and reviewed by the hearing examiner, but the fact that the development is proposing to implement cluster subdivision may not be used as a criterion or defense for proposing the modification.
E. The hearing examiner shall not modify the results of the calculations of this chapter as described above, and shall not modify the minimum lot size reduction authorized by this chapter below the standard as provided in SMC 19.46.040(A). (Ord. 1353-21 § 3 (Att. B))