Auburn City Zoning Code
18.25 Middle
Housing Development Standards
18.25.010 Purpose and intent.
The purpose of this chapter is to encourage the development of underutilized parcels in zones which, through Auburn comprehensive plan goals and policies, have been identified as areas where middle housing should be encouraged. Middle housing shall be compatible in scale, form, and character with single-unit detached houses that are allowed within the underlying zoning designation. This chapter identifies the standards for middle housing development. (Ord. 6959 § 1 (Exh. A), 2024; Ord. 6245 § 14, 2009.)
18.25.020 Applicability.
A. Eligibility Criteria. This chapter may be applied to development or redevelopment that meets the following criteria:
1. The lot is within one of the following zones: RC, R-1, R-2, R-3, R-4, R-NM.
B. Exceptions. This chapter may be applied to development or redevelopment, except for the following:
1. Middle housing is not permitted within urban separators.
2. Middle housing is not permitted in the R-HMC zone.
3. Middle housing is not permitted on lots smaller than 1,000 square feet.
4. Middle housing provisions do not apply to portions of a lot, parcel, or tract designated with critical areas designated under RCW 36.70A.170 or their buffers as required by RCW 36.70A.170, except for critical aquifer recharge areas where a single-family detached house is an allowed use; provided, that any requirements to maintain aquifer recharge are met. (Ord. 6977 § 1 (Exh. A), 2025; Ord. 6959 § 1 (Exh. A), 2024; Ord. 6245 § 14, 2009.)
18.25.030 Procedures.
Development proposals desiring to utilize the middle housing standards of this chapter shall be subject to one or more of the permit types found in ACC Title 14 and shall be processed in a manner consistent with the underlying land use application pursuant to ACC Title 14. (Ord. 6959 § 1 (Exh. A), 2024; Ord. 6245 § 14, 2009.)
18.25.040 Middle housing types.
A. For the purposes of this chapter middle housing refers to all housing consisting of between two and six units per lot, defined in ACC 18.04.340(B). (Ord. 6959 § 1 (Exh. A), 2024; Ord. 6245 § 14, 2009.)
18.25.050 Parking requirements.
A. Within one-half mile walking distance of a major transit stop no on-site parking is required.
B. On lots that are more than one-half mile walking distance of a major transit stop, one on-site parking space shall be required for each dwelling unit.
C. On-site parking spaces shall include garage and/or driveway parking spaces.
D. When calculating parking relative to the above referenced lot sizes, the calculation shall occur prior to zero lot line land divisions. (Ord. 6959 § 1 (Exh. A), 2024.)
18.25.060 Accessory dwelling units.
A. An ADU is considered a dwelling unit when calculating the number of units allowed on a lot or as part of a development proposal. Example: If four units are the base units on a given lot, and a fourplex has been developed, no ADUs may be added.
B. ADUs must be accessory to a single-unit detached unit or middle housing unit.
C. ADUs are subject to the standards contained in Chapter 18.32 ACC.
For the purposes of total number of units allowed on a lot pursuant to ACC 18.02.067, “dwelling units” includes accessory dwelling units (ADUs). Example: If four units are the base units on a given lot, and a fourplex has been developed, no ADUs may be added. (Ord. 6959 § 1 (Exh. A), 2024.)
18.25.070 Middle housing design standards.
A. Applicability.
1. Standards in this section apply to all development between two and six units per lot.
2. For the purposes of this section, a “street” refers to any public or private street.
3. These design standards do not apply to the conversion of a structure to a middle housing type with up to four attached units, if the floor area of the structure does not increase more than 50 percent.
B. Purpose. The purpose of these standards is to:
1. Promote compatibility of middle housing with other residential uses, including single-unit detached dwellings.
2. De-emphasize garages and driveways as major visual elements along the street.
3. Provide clear and accessible pedestrian routes between buildings and streets.
4. Implement the definitions of cottage housing and courtyard apartments provided by state law.
C. Pedestrian Access. A private, paved pedestrian connection that is a minimum of three feet wide required between each middle housing building and the public sidewalk (or the public street if there is no sidewalk). Driveways may be used to meet this requirement.
D. Vehicle Access, Carports, Garages, and Driveways.
1. Garages, driveways, and off-street parking areas shall not be located between a building and a street, except when either of the following conditions are met:
a. The combined width of all garages, driveways, and off-street parking areas does not exceed a total of 60 percent of the length of the street frontage property line. This standard applies to buildings and not individual units; or
b. The garage, driveway, or off-street parking area is separated from the street property line by a dwelling; or
c. The garage, driveway, or off-street parking is located more than 100 feet from a street.
E. Landscaping. See ACC Table 18.50.040(A), Minimum Landscape Requirements by Zoning District, for landscaping requirements.
F. Entries. Each building shall incorporate a primary building entry or one or more private unit entries, such as a covered porch or recessed entry. Each entry shall feature minimum weather protection of three feet by three feet.
G. Windows and Doors. A minimum of 15 percent of the area of the street-facing facade elevation shall include windows or doors. Facades separated from the street by a dwelling or located more than 100 feet from a street are exempt from this standard.
H. Unit Articulation.
1. Applicability.
a. Each attached unit featuring a separate ground level entrance in a multi-unit building facing the street shall include at least one of the articulation options listed in subsection (H)(2) of this section.
b. Facades separated from the street by a dwelling or located more than 100 feet from a street are exempt from this standard.
2. Articulation Options. Option 1. Roofline change or a roof dormer with a minimum of four feet in width.
Option 2. A balcony a minimum of two feet in depth and four feet in width and accessible from an interior room.
Option 3. A bay window that extends from the façade a minimum of two feet.
Option 4. An offset of the facade of a minimum of two feet in depth from the neighboring unit.
Option 5. A roofed porch at least 50 square feet in size.
Option 6. Change in wall color.
Figure 18.25.070(H). Articulation Options
I. Middle Housing Design Review Submittal Requirements. In addition to other documentation required for submittal of a complete application for building permit or discretionary land use approvals/permits, subsections (I)(1) and (I)(2) of this section shall be required for review of building design. Middle housing design review is subject to administrative design review that shall be completed through the building permit and/or discretionary land use approvals/permits.
1. Elevation drawings prepared by an architect licensed in the state of Washington of all proposed construction including dimensional drawings at one-eighth inch equals one foot or comparable scale showing the type of exterior materials, color, exterior finishes (including for accessory structures, where applicable), articulation, fenestration details, and the location, elevations, type, style and model of any exterior lighting fixtures (where applicable).
2. As applicable, a to-scale landscape plan consistent with Chapter 18.50 ACC. (Ord. 6959 § 1 (Exh. A), 2024.)
18.25.080 Courtyard housing standards.
A. Applicability. Standards in this section apply to courtyard housing, which includes cottage housing (detached units) and courtyard apartments (attached units).
B. Open Space. Open space shall be provided equal to a minimum 20 percent of the lot size. This may include common open space, private open space, setbacks, critical areas, and other open space.
C. Common Open Space.
1. At least one outdoor common open space is required.
2. Common open space shall be provided equal to a minimum of 300 square feet per unit. Each common open space shall have a minimum dimension of 15 feet on any side.
3. Orientation. Common open space shall be bordered by dwellings on at least two sides. At least half of all units in the development shall abut a common open space and have the primary entrance facing the common open space.
4. Parking areas and vehicular areas shall not qualify as common open space.
5. Critical areas and their buffers, including steep slopes, shall not qualify as common open space.
D. Community Building.
1. A courtyard housing development shall contain no more than one community building.
2. A community building shall have no more than 2,400 square feet of net floor area, excluding attached garages.
3. A community building shall have no minimum off-street parking requirement. (Ord. 6959 § 1 (Exh. A), 2024.)
18.25.090 Usable open space.
A. All middle housing development must include usable open space.
B. Usable open space must occupy at least 10 percent of the lot with a minimum dimension of at least 10 feet. Usable open space may be a single large space or several separate spaces. Unenclosed porches, patios, and entries may count towards usable open space if contiguous with a space that meets the standards of this section. Areas of usable open space with no unenclosed porches, patios, and entries or other similar features may overlap with the required landscaped areas within Table 18.50.040(A).
C. Driveways and parking areas may not count towards usable open space.
D. Where usable open space is located within the front setback, the open space must be defined with a fence, hedge, or wall, at least 24 inches tall.
E. LID stormwater BMPs, like rain gardens, may be integrated in up to 25 percent of the minimum required usable open space area.
F. Additions must not create or increase any nonconformity with this standard.
Figure 18.25.090. Usable Open Space
(Ord. 6959 § 1 (Exh. A), 2024.)