Chapter 17.28 SUBDIVISION DEVELOPMENT STANDARDS

Prior to the construction of any minimum improvements, as approved upon the preliminary plat or binding site plan, the subdivider shall furnish certain construction plans. These plans must be prepared, signed, dated and stamped by a Washington State licensed civil engineer and shall be in accordance with the City of Sumner Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.020 Preparation of construction drawings.

The construction plans shall be developed as specified in the City of Sumner Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.030 Standards and specifications.

City of Sumner Development Specifications and Standard Details are the “standards” together with the laws of the state of Washington. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.040 Plan review, inspection and fees.

No permit shall be issued under the provisions of this chapter until plans for the proposed work have been submitted and approved by the public works department. Upon approval by the public works department, the permit shall be issued and charges made, calculated as follows:

A. Base permit fee: $50.00.

B. Plan Review Fee.

• One hour x current engineering burdened rate (minimum);

• In-house plan review fee: Hours x current engineer burdened rate;

• Third-party review fees as billed to the city, including city administrative costs.

C. Inspection Fee.

• Two hours x current inspector burdened rate (minimum);

• ([[# LF Water/250] x 4] + 10) x current inspector burdened rate;

• Additional inspection as warranted: Number of hours x current staff burdened rate.

The total fee for permit approval shall be the sum of the above elements. Plan review fees shall be accrued until the construction plans are approved for construction. Accrued plan review fees shall be paid regardless of whether a permit is issued. Inspection fees shall be accrued until final project approval and shall be assessed to the permittee as they are accrued. Burdened rates for city staff are actual salaries plus benefits with a 1.25 multiplier to cover indirect costs. City staff burdened rates are specified in the Sumner utility rate and fee schedule. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.050 Required improvements – Full subdivisions.

Minimum improvements within each major plat or binding site plan and along contiguous arterials shall consist of paved streets or private drive aisles in zero lot line subdivisions per the requirements of this title, installed curbs and gutters, sidewalks, monuments, sanitary and storm sewers, street lights, water mains, street trees, street name signs and all appurtenances thereto in accordance with the adopted city transportation and utility comprehensive plans and the Sumner development specifications and standard details. (Ord. 2842 § 2, 2023; Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.060 Required improvements – Short subdivisions.

Street, water, sewer and storm drainage facilities adjacent to or within a short subdivision shall be in conformance with the adopted city transportation and utility comprehensive plans and the Sumner development specifications and standard details. Access to zero lot line subdivisions shall consist of private drive aisles meeting the standards at SMC 17.28.205, unless a public street is otherwise required by this title. Easements for utilities recommended by such plans shall be provided to the city, the exact location of such easements to be determined by the city engineer.

A. Whenever certain improvements, such as street, water, sewer or storm drainage, are required to be extended to service a short subdivision or within the short subdivision, the subdivider shall furnish construction plans for these improvements. These plans must be prepared, signed, dated and stamped by a professional civil engineer registered in the state of Washington. These plans shall be in accordance with the Sumner Development Specifications and Standard Detail as outlined in the formal subdivision requirements.

B. The city engineer has the authority in determining whether these plans must be submitted and approved prior to the acceptance of the short subdivision.

C. Requirements for street dedications within the plat are the same as those of formal subdivisions. (Ord. 2842 § 3, 2023; Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.070 Bond required.

A. Performance and Payment Bond. No permit shall be issued under the provisions of this chapter until the applicant therefor executes and delivers to the city a bond, or an assignment of funds in lieu of bond, in the sum of $5,000, or 120 percent of the cost of the project, whichever is greater, the form to be approved by the city attorney, and with surety approved by the city treasurer conditioned on the faithful performance of the provisions of this chapter. The bond shall be conditioned that the applicant acting under the permit shall complete roadway, sanitary sewer, water system, erosion control and/or other improvements as shown on the construction plans as approved by the public works department. Such bond shall further be conditioned to indemnify and hold harmless the city from any and all judgments, costs or expenses arising from injuries or damage to any person or property on account of such work. Such bond shall remain in full force and effect until final project acceptance by the Sumner city council.

See Chapter 1 of the Sumner Development Specifications for additional information regarding final project acceptance.

The application shall also be required to execute a stormwater facilities bond as specified in chapter 13.48 SMC.

B. Maintenance and Defect Bond. After satisfactory completion of the improvements and prior to release of the performance and payment bond by the city, the developer/contractor shall commence a two-year period where the improvements are maintained and operated by the city of Sumner. A cash or surety bond to be used at the discretion of the public works department to correct design and/or workmanship defects and maintenance deficiencies affecting public health, safety, and welfare shall be posted and maintained throughout the two-year maintenance period by the developer/contractor. The amount of the bond shall be 20 percent of the actual construction cost of the public improvements.

A stormwater maintenance and defect bond shall also be provided per chapter 13.48 SMC. Landscape bonding shall be provided per SMC 18.41.090. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.080 Clearing and grading.

All streets, roads and alleys shall be graded to their full width so that pavement and sidewalks can be constructed on the same plane. Before grading is started, the entire right-of-way area shall be cleared of all stumps, roots, brush and other objectionable materials, and all trees not intended for preservation. Documentation will be kept by the permit holder of the location and type of fill on private property. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.090 Monuments.

Concrete monuments shall be set at all corners of the subdivision, at all points where the street lines intersect the exterior boundaries of the subdivision, at angle points and points of curvature in each street, and at all street intersections. All surveys shall be of second degree accuracy. The use of state plan coordinates NAD 83-91 and NGVD-29 is required. All other lot corners shall be marked with a permanent suitable metal marker not less than three-eighths inch in diameter and 24 inches long and driven flush with the finished grade. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.100 Street and block layout.

The subdivision shall abut on and/or be served by an open, maintained public street(s) and the street and block layout shall conform to the most advantageous development of adjoining areas of the entire neighborhood, and shall provide for the following:

A. Continuity of appropriate streets and arterials;

B. Streets generally following contour lines where practicable;

C. Offset intersections shall be avoided;

D. Streets intersecting at right angles, or as nearly as possible, are subject to approval by the city engineer or his or her designee; and

E. Streets meeting the minimum right-of-way and pavement width standards. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.110 Block requirements.

A block shall consist of any two or more contiguous lots which are not separated by a street. Blocks shall meet the following requirements:

A. Wherever appropriate, blocks shall provide for two tiers of lots, except that one tier of lots is encouraged between a residential street and an arterial, which lots shall front on and be accessed from the residential street or from any alley constructed between the two tiers of lots; and

B. Where the average area of lots does not exceed two acres, the distance between intersections along a street or arterial shall not exceed 1,320 feet; and

C. Where the average area of lots does not exceed two acres, and where there are two tiers of lots lying between approximately parallel streets or arterials, and where the distance between intersections along a street or arterial exceeds 660 feet, a walk or pedestrian right-of-way running between lots and lying roughly perpendicular to the street or arterial shall be provided at approximately mid-block point, the right-of-way of which shall be at least 12 feet in width and fully paved as approved by the city engineer or his or her designee; and

D. The number of streets intersecting with existing or proposed arterials shall be held to a minimum consistent with the provision of this section and consistent with adequate local circulation. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.120 Street design criteria – Street grades.

Street grades, horizontal curves, and vertical curves shall conform to the requirements of the Sumner Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.130 Access for short subdivisions.

A. Private Access Allowed. All short subdivisions and zero lot line short subdivisions shall either border on an opened, constructed and maintained public street, or shall be served by a private road, private drive aisle or shared driveway having direct access to a public street as set forth in this chapter.

B. Public Streets Required. Dedication of a public street or streets serving the short subdivision or zero lot line short subdivision shall be required whenever the city engineer or his or her designee finds that one or more of the following conditions applies:

1. The general alignment of a proposed private road follows the general alignment of a future arterial recommended by the comprehensive plan.

2. The general alignment of a proposed private road can be reasonably modified to provide a desirable through connection between two or more existing or planned public streets.

3. A public street would be necessary to provide adequate access to adjacent property not subject to the proposed short subdivision.

4. The subdivision is an accumulative short subdivision under SMC 17.12.090.

C. All private roads shall meet the standards as set forth in SMC 17.28.200. All private drive aisles shall meet the standards as set forth in SMC 17.28.205.

D. When any approved public street lying adjacent to the property being short subdivided or zero lot line short subdivided has insufficient width or for any other reason does not conform to minimum street standards, sufficient additional right-of-way shall be dedicated to the city and appropriate improvements shall be made by the subdivider to conform the abutting street to such standards in order to provide street and traffic infrastructure to support the development. Such improvements may be delayed if guaranteed to the satisfaction of the city engineer or his or her designee. Any such guarantee shall be recorded with the plat and shall be binding upon the property owner and the owner’s heirs, successors and assigns. In deciding whether any delays should be allowed, the city engineer or his or her designee shall consider the present and future need for such improvement, the improved or unimproved nature of adjacent right-of-way, and whether or not street grades have been established. (Ord. 2842 § 4, 2023; Ord. 2358 § 1 (part), 2011: Ord. 1886 § 3, 1999: Ord. 1763 § 1 (part), 1996)

17.28.140 Principal arterials.

Proposed and existing principal arterials located within or adjacent to the subdivision as designated by the Sumner comprehensive plan shall be dedicated to the city and constructed or improved to meet the Sumner Development Specifications and Standard Details by the subdivider or their agent. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.150 Minor arterials.

Proposed and existing arterials located within or adjacent to a subdivision, as designated by the city engineer or his or her designee in consultation with the Sumner comprehensive plan, shall be dedicated to the city and constructed or improved to meet the city’s Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.160 Residential arterials (collectors).

Proposed and existing arterials located within or adjacent to the subdivision, as designated by the city engineer or his or her designee in consultation with the Sumner transportation comprehensive plan, shall be dedicated to the city and constructed or improved to meet the city’s Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.170 Local residential streets.

Proposed and existing streets, other than designated arterials, which are located within or adjacent to the subdivision, and which are to serve property primarily designated for residential uses, shall be constructed or improved to meet the city’s Development Specifications and Standard Details; provided, that where the city council finds it necessary for the provision of safe and efficient circulation, the council may require any such streets to be developed or improved to residential arterial standards. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.180 Neighborhood streets.

Proposed and existing streets which are located within or adjacent to the subdivision, and which are to serve property primarily designated for residential uses, shall be designated neighborhood streets. Such a street shall generally not be longer than 300 feet, should have limited through traffic, should function as part of a grid of similar streets providing access to an area, and may be in conjunction with alleys which provide secondary access to lots. Neighborhood streets shall be constructed or improved to meet the city’s Development Specifications and Standard Details; provided, that where the city council finds it necessary for the provision of safe and efficient circulation, the council may require any such streets to be developed or improved to local residential street standards. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996)

17.28.190 Alleys.

Alleys may be provided to the rear of lots zoned for commercial or residential purposes. Alleys shall be constructed or improved to meet the city’s Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 2253 § 2, 2008: Ord. 1786 § 1, 1997: Ord. 1763 § 1 (part), 1996)

17.28.195 Pipestem lots.

A. Pipestem lot subdivisions are allowed the following number of contiguous pipestem lots:

1. Up to two lots are allowed behind an existing lot provided the existing lot retains a minimum street frontage of 15 feet; or

2. Up to four lots are allowed to be subdivided from a parent lot, or are allowed behind an existing lot provided the existing lot retains a minimum street frontage of 30 feet; or

3. Up to five lots are allowed if an existing dwelling unit is included in and preserved as part of the subdivision.

B. Pipestem lots shall be served by a strip of land not less than the minimum width to accommodate the required private road for access, as such access is described in SMC 17.28.200, and shall be designed for the purpose of providing access to the buildable area of the lot or tract.

C. Pipestem lots may access the street network by way of shared driveways or private drive aisles as provided in SMC 17.28.200 and 17.28.205. (Ord. 2851 § 4, 2023; Ord. 2588 § 3, 2016)

17.28.200 Private roads.

A. Short subdivisions, except for pipestem lots, may be served by a private road as follows:

1. Access for up to four lots may be via a shared driveway with a minimum width of 15 feet, with an 11-foot-wide paved travel surface and two two-foot-wide shoulders.

2. Access for five to nine lots may be via a private drive aisle in conformance with the standards in SMC 17.28.130 and 17.28.205, unless a public street is required pursuant to SMC 17.28.130(B).

B. Pipestem lot short subdivisions may be served by a private road as follows:

1. Access for up to two pipestem lots may be via a shared driveway with a minimum width of 15 feet, with an 11-foot-wide paved travel surface and two two-foot-wide shoulders.

2. Access for three to four pipestem lots shall require a private drive aisle subject to the provisions of SMC 17.28.205, except that the private aisle shall provide at a minimum a 20-foot-wide paved travel surface and one five-foot-wide designated pedestrian corridor to the public street.

C. Private roads shall be improved or guaranteed to the standards considered appropriate to the situation by the city engineer and fire marshal, and shall meet the applicable requirements of the fire marshal and city’s Development Specifications and Standard Details. (Ord. 2851 § 5, 2023; Ord. 2588 § 4, 2016: Ord. 2358 § 1 (part), 2011: Ord. 1886 § 4, 1999. Formerly 17.28.195)

17.28.205 Private drive aisles.

A. Applicability. The provisions of this section apply exclusively to the zero lot line subdivision and zero lot line short subdivision of land for attached single-family dwellings. For the purposes of this section, the term “subdivision” includes zero lot line subdivision and zero lot line short subdivision.

B. Access to individual dwelling units within a zero lot line subdivision may be provided by a private road or private drive aisle, except that a public street shall be required whenever the city engineer or his or her designee finds that any of the conditions listed in SMC 17.28.130(B), Access for Short Subdivisions, apply.

C. Private drive aisles shall meet the following minimum standards:

1. Where private drive aisle takes access from another private drive aisle with no direct connection to a public street:

a. Provide a minimum 15-foot-wide travel surface; provided the fire marshal approves an alternate access for fire/emergency vehicles; and

b. Provide a minimum five-foot-wide pedestrian walkway except where the drive aisle provides access to the rear of the units and pedestrian access to the units is provided on another street or private drive aisle.

2. Where private drive aisle directly connects to a public street:

a. Provide a minimum 20-foot-wide travel surface; and

b. Provide two five-foot-wide sidewalks for a total 30-foot drive aisle width.

3. Private drive aisles may include designated parking lanes, where adequate travel surface is provided. Total width of a private drive aisle with parking lanes shall be the required width of the travel surface and any required walkway plus the required dimension of the parking stalls as stated in SMC 18.42.030(B), minimum parking area dimensions.

4. Surfacing.

a. Private drive aisles shall be paved with asphalt or concrete.

b. Private drive aisles shall comply with the adopted alley cross-section in the city of Sumner development specifications and standard details, specifically Detail R6-2.1 and R6-2.2, or as hereinafter amended.

D. Private drive aisles shall be placed in a separate tract or easement and owned in common between all property owners within the subdivision or short subdivision. (Ord. 2851 § 6, 2023; Ord. 2842 § 5, 2023)

17.28.210 Dead-end streets.

Dead-end streets shall be constructed or improved to meet the minimum requirements of the city’s Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.200)

17.28.220 Street lighting.

Street lighting shall conform to the Sumner Development Specifications and Standard Details and shall be provided and installed by the subdivider. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.210)

17.28.230 Street trees.

Street tree planting must be approved by the community development director or his or her designee prior to planting and shall conform to the City of Sumner Development Specifications and Standard Details. See chapter 12.42 SMC for street tree requirements. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.220)

17.28.240 Underground utilities.

The following standards and specifications apply to underground utilities:

A. All utility lines serving the subdivisions including, but not limited to, power, telephone and television cables shall be installed underground. Easements shall be provided for all such utility lines which will not be located within the public right-of-way;

B. Whenever an intersection of an arterial and any other street is constructed or improved under the requirements of this chapter, and when the city engineer or his or her designee has determined that traffic signalization of such intersection will be needed in the future, the city engineer or his or her designee may require the installation, at the subdivider’s expense, of underground conduit which will be necessary for and will facilitate such future signalization;

C. A 10-foot utility easement is required along the frontage of each lot adjacent to the street right-of-way for the installation of the aforesaid utilities; and

D. All lots are subject to an easement two and one-half feet in width, parallel with and adjacent to all interior lot lines and five feet in width parallel with and adjacent to all rear lot lines for the purpose of utilities and private drainage. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.230)

17.28.250 Street signs and channelization.

The subdivider shall provide and install all required traffic regulatory signs, street name signs and street striping and channelization as directed by the city engineer or his or her designee and in compliance with all applicable standards and regulations. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.240)

17.28.260 Sidewalks.

Concrete sidewalks shall be installed by the developer on both sides of the street in conformance with the Sumner Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.250)

17.28.270 Curbs and gutters.

The developer shall provide permanent concrete curbs and gutters according to the Sumner Development Specifications and Standard Details. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.260)

17.28.280 Sanitary sewers.

Each lot in a subdivision shall be served by the Sumner sanitary sewer system, designed and installed subject to the review and approval of the city engineer or his or her designee, unless the city finds that:

A. City sanitary sewer service is not practical due to topography, distance from city sanitary sewer facilities of adequate capacity, extremely low proposed development density, or similar factors; and

B. On-site sewage disposal systems will not be detrimental to the implementation of the adopted comprehensive sewerage plan; and

C. On-site sewage disposal systems will not pose a threat to the public health, safety or welfare; and

D. On-site sewage disposal systems are necessary to accomplish the purposes of this chapter;

E. The city engineer or his or her designee has reported favorably on the use of on-site sewage disposal systems; and

F. Each lot to be served by an on-site sewage disposal system shall meet the minimum lot area requirements of the Tacoma-Pierce County health department rules and regulations, or be not less than 15,000 square feet in area. Land contained in access easements or access panhandles shall not be included in lot area calculations for the purposes of this section. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.270)

17.28.290 Water.

The water distribution system, including fire hydrants, shall be designed and installed in accordance with Sumner Development Specifications and Standard Details and the requirements of the public works department and the fire marshal. Each lot in a subdivision shall be served by the city of Sumner unless the city finds that:

A. City water service is not practical due to topography, distance from city water facilities of adequate capacity, extremely low proposed developmental density, or similar factors, or legal constraints; and

B. Private water service will not be detrimental to the implementation of the adopted comprehensive water plan; and

C. Private water service will not pose a threat to the public health, safety or welfare; and

D. Private water service is necessary to accomplish the purposes of the chapter. If private water service is approved, preliminary plat approval shall be conditioned on the ability of the subdivider to obtain all necessary approvals for the private water system or systems, and the final plat shall not be approved until the subdivider demonstrates, to the satisfaction of the city engineer or his or her designee, that the proposed water system or systems will adequately serve the domestic water and fire flow needs of future owners or property within the subdivision. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.280)

17.28.300 Storm drainage.

Stormwater control facilities shall be designed and constructed in accordance with the Sumner Development Specifications and Standard Details Chapter 5. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.290)

17.28.310 Floods and flood control.

The city may disapprove a proposed subdivision because of flood, inundation or regulated wetlands if the city finds that such condition poses a threat to the public health, safety or general welfare. Where any portion of the proposed subdivision lies within one percent flood hazard area or the regulatory floodway, the city shall impose a condition on the preliminary plat requiring the subdivider to conform to the Federal Emergency Management Agency (FEMA) flood hazard requirements. In such cases, no development permit associated with the proposed subdivision shall be issued by the city until said FEMA requirements have been met. The city may require dedication of land to any public body and/or the construction of improvements and may impose other conditions necessary to protect against flooding or inundation. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.300)

17.28.320 Additional requirements.

The standards and requirements established or referenced by this chapter are minimum requirements. These standards may be increased and additional requirements may be imposed for the purpose of mitigating identified adverse environmental impacts pursuant to the State Environmental Policy Act of 1971 as now established or hereafter amended. Such additional requirements may include, but shall not be limited to, off-site improvements to any public facility, the dedication and/or improvement of parks and open spaces, and monetary contributions to any city fund established to finance the provision of public services required by the subdivision. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.310)

17.28.330 Phased subdivision.

Preliminary plat approval must be granted for the entire subdivision and must delineate the separate divisions which are to be developed in increments. The preliminary plat approval is conditioned upon completion of the proposed phases in a particular sequence and may specify a completion date for each phase. Final plat approval is granted for each separate phase of the preliminary plat and any changes at the preliminary plat stage would require approval per SMC 18.56.030. (Ord. 2358 § 1 (part), 2011: Ord. 1763 § 1 (part), 1996. Formerly 17.28.320)

17.28.340 Development standards for zero lot line subdivisions and zero lot line short subdivisions.

A. Applicability. The provisions of this section apply exclusively to the zero lot line subdivision and zero lot line short subdivision of land for attached single-family dwellings, such as townhouse, cottage housing, or multiplex developments in zones where such uses are allowed. For the purposes of this section, the term “subdivision” includes zero lot line subdivision and zero lot line short subdivision.

B. Zero lot line subdivisions may be used to subdivide a parcel(s) into individual lots that each contain one housing unit. The development shall meet the development standards applicable to the underlying site and zone. Any private open space for each dwelling unit shall be provided on the same lot as the dwelling unit.

C. Zero lot line lot area and lot width per lot for purposes of subdivision may be as small as the minimum lot area and lot width specified in SMC 18.14.070 plus any required private open space.

D. Zero lot line subdivisions are also subject to the lot dimensions, lot coverage, open space requirements and other development standards at SMC 18.14.070 and performance standards at SMC 18.14.080.

E. Parking for Zero Lot Line Subdivisions.

1. Provide a minimum of two stalls per unit, which may be covered.

2. Required spaces and access drives shall be improved with asphalt, concrete, or similar dustless, hard surface. Tandem parking may be allowed at a maximum of 30 percent of the per-unit on-site parking stalls.

3. Visitor stalls shall be provided at one-quarter stalls per unit; stalls may be provided on site or as on-street parking if located within 250 feet of the development on a public street that abuts the development, provided no more than 50 percent of the required guest parking is allowed off site.

F. Driveways. Driveways for any unit with a private driveway shall be a minimum of 18 feet deep.

G. Open Space. Minimum open space shall be provided as follows:

1. Minimum private open space per lot shall be 200 square feet per unit; and minimum common open space per lot shall be 100 square feet per unit; except that open space may be reduced in accordance with subsection (G)(2) of this section.

2. Zero lot line subdivisions and zero lot line short subdivisions with 12 or fewer units or that provide private open space at an additional 25 percent per unit may receive a waiver from this requirement if the applicant can demonstrate that the development is within a quarter-mile of a public park and adequate pedestrian facilities to said park serve the site.

3. Open space shall be useable and directly accessible from the unit. Required setback areas with a dimension less than 10 feet shall not be counted toward the minimum required open space.

H. Prior to final subdivision approval and recording, site development may commence upon approval of clearing and grading plans, and building construction may commence upon approval of all applicable building design and construction approvals. (Ord. 2842 § 6, 2023)

17.28.350 Maintenance and recording zero lot line subdivisions and zero lot line short subdivisions.

A. Portions of the parent lot not subdivided for individual zero lot line units shall be owned in common by the owners of the individual lots, or by a homeowners association comprised of the owners of the individual lots located within the parent lot.

B. Access easements, joint use and maintenance agreements, and covenants, conditions and restrictions identifying the rights and responsibilities of property owners and/or the homeowners association for use and maintenance of common garage, parking, and vehicle access areas; on-site recreation areas; landscaping; underground utilities; common open space; exterior building facades and roofs; and other similar features, shall be executed and recorded with the county auditor’s office.

C. A zero lot line subdivision shall make adequate provisions for ingress, egress, and utilities access to and from each lot created by reserving such common areas or other easements over, under, and across the parent lot as deemed necessary to comply with all other design and development standards generally applicable to the underlying site, and such easements shall be recorded with the county auditor’s office and depicted on the face of the recorded final subdivision or short subdivision map.

D. Each lot in a zero lot line subdivision shall provide a five-foot-wide building maintenance easement for walls, eaves, chimneys, and other architectural features that rest directly on the lot line. The maintenance easement shall be included in the covenants, conditions, and restrictions of the adjoining lots, and shall be recorded with the covenants, conditions, and restrictions, and depicted on the face of the recorded final subdivision or short subdivision map.

E. Notes shall be placed on the plat recorded with the county auditor’s office to acknowledge the following:

1. Approval of the design and layout of the development was granted by the review of the development, as a whole, on the parent lot by the site development plan approval;

2. Subsequent platting actions, additions or modifications to the structure(s) may not create or increase any nonconformity of the parent lot as a whole, and shall conform to the approved preliminary zero lot line subdivision;

3. If a structure or portion of a structure has been damaged or destroyed, any repair, reconstruction, or replacement of the structure(s) shall conform to the approved preliminary zero lot line subdivision or short subdivision; and

4. Additional development of the individual zero lot line lots may be limited as a result of the application of special development standards to the parent lot. (Ord. 2842 § 7, 2023)

17.28.360 Conversion of existing dwellings to zero lot line dwellings.

A. Purpose. The purpose of this section is to provide a streamlined subdivision process for certain condominium and multiplex dwellings that convert into fee simple ownership dwellings, thereby increasing home ownership options in the community.

B. Applicability. This section applies to the following types of residential dwellings:

1. Duplex and multiplex dwellings lawfully constructed under a valid building permit prior to January 1, 2022; or

2. Townhouse condominiums for which a binding site plan or site development permit was issued by the city after January 1, 2018; and

3. Are located in the medium density residential or high density residential zones.

C. No increase in the number of existing dwelling units is allowed, except that additional zero lot line dwellings may be created, provided:

1. The maximum allowable density for the zone is not exceeded; and

2. Any new dwellings are subject to standards for new zero lot line dwellings in SMC Titles 17 and 18.

D. The director may approve the conversion of residential dwellings subject to this section to zero lot line dwellings, subject to all of the following:

1. The conversion shall be processed as a short subdivision or full subdivision under SMC Title 17 based on the number of proposed lots, in accordance with SMC 17.04.040(A).

2. The conversion application shall include submittal of the applicable subdivision land use permit fee established at SMC 18.56.060.

3. The conversion application shall include maintenance agreements, covenants and owner concurrence documents, containing:

a. A copy of the site development permit issued by the city or, where such permit document is not available, a current site plan showing buildings, landscaping, parking and infrastructure;

b. Maintenance and recording documents required in SMC 17.28.350;

c. A copy of any existing recorded covenants, conditions and restrictions, property owners’ association bylaws and incorporation documents, and all other private restrictions or provisions currently applicable or which may become applicable to the subject property; and

d. Evidence of the vote or applicable association community approval by a majority with ownership interest authorizing the submittal of the application for conversion.

4. The conversion development shall comply with requirements in this chapter for zero lot line subdivisions and zero lot line short subdivisions, except that the director may waive the following standards:

a. Lot dimensions and other development standards; provided, the parent lot is in compliance with the applicable codes for the existing development; and

b. Street and access standards; except as follows:

i. Where an existing development being subdivided pursuant to this section would otherwise be required to comply with SMC 17.28.130 requirements for a public street, the director may require an alternate public connection through the subject property that provides a pedestrian or driveway connection to the public street system.

5. Dwellings subject to this section are not subject to chapter 18.40 SMC, design and development guidelines; provided, that the director may require administrative design review of new dwellings.

6. The conversion development is deemed to have satisfied the standards in effect at the time of original permit approval and, therefore, is not required to satisfy new traffic study requirements or traffic concurrency review, nor required to pay traffic impact fees or system development charges; except as otherwise required for any new dwellings, or expansion of existing infrastructure or impervious surfaces.

7. Where no increase in number of dwellings, or expansion of existing infrastructure or impervious surfaces is proposed, the conversion development is deemed to have satisfied the standards in effect at the time of original permit approval and, therefore, is not required to satisfy current requirements for studies, reviews, impact fees or infrastructure upgrades, as provided below:

a. Traffic study requirements, traffic concurrency review, traffic impact fees and system development charges are not required;

b. Upgrades to current fire and building code are not required, provided the fire marshal and building official determine that the development satisfies applicable International Fire Code and International Building Code requirements.

c. Upgrades to infrastructure are not required, provided the city engineer determines that the development currently provides access, water, sewer and storm drainage facilities consistent with applicable city transportation and utility comprehensive plans and the Sumner development specifications and standard details. Where deemed necessary for public convenience or safety, the city engineer may require a sidewalk to be installed or repaired along the development street frontage.

8. Pursuant to SMC 16.04.100(A), a SEPA environmental checklist is not required and a SEPA threshold determination is not required for a conversion development where SEPA compliance has been completed; provided, that the conversion is substantially in conformance with the original scope, and that any new dwellings and expansion do not exceed adopted SEPA categorical exemption thresholds under SMC 16.04.085.

E. Approval Criteria. The director shall find that all of the following exist before approving conversions under this section:

1. The conversion will not cause the subdivision to be incompatible with the previously approved site plan in effect at the time of conversion.

2. Residents and owners of each unit to be converted have received a 90-day notice of the conversion.

3. The conversion will not cause the subdivision to violate any applicable city policy or regulation.

4. The conversion will not create undue detrimental impacts to the surrounding land uses or natural environment. (Ord. 2842 § 8, 2023)