4-2-116 ACCESSORY DWELLING UNIT RESIDENTIAL DESIGN STANDARDS:

A. PURPOSE:

Accessory dwelling units (ADUs) are intended to create affordable, flexible housing opportunities that take advantage of the City’s existing infrastructure while addressing the need for increased housing choices that reflect changing lifestyles and environmental concerns.

The purpose of this Section is to encourage development that enhances quality of life by encouraging new residential development to produce neighborhoods of well-designed homes and promote and facilitate ADU construction in new and existing developed areas, while preserving neighborhood character and ensuring minimal disruption to surrounding property owners.

This Section lists elements that are required to be included in all ADU development in the zones stated in subsection B of this Section. Each element includes both standards and guidelines. Standards are provided for predictability. These standards specify a prescriptive manner in which the requirement can be met. Guidelines for each element are provided for flexibility. These guidelines provide direction for those who seek to meet the required element in a manner that is different from the standards.

1. The determination as to the satisfaction of the requirement through the use of the guidelines is to be made by the Community and Economic Development Administrator when no other permit or approval requires Hearing Examiner review.

2. When it has been determined that the proposed manner of meeting the design requirement through guidelines is sufficient, that design requirement shall be considered satisfied.

B. APPLICABILITY:

1. This Section shall apply to ADUs in the following zones: Residential-4 (R-4), Residential-6 (R-6), Residential-8 (R-8), Residential-10 (R-10), and Residential-14 (R-14).

2. If the primary structure where the ADU is proposed does not comply with the adopted architectural detailing standards adopted in the residential design standards (RMC 4-2-115E3), the primary structure shall be brought to proportional compliance prior to the issuance of ADU building permits.

a. The amount invested in physical improvements to reduce or eliminate the nonconformity related to the architectural detailing shall be determined by multiplying the valuation of the ADU, as determined by the City, by ten percent (10%).

b. The Department shall evaluate and approve the allocation of the required investment in bringing the primary structure into compliance based on the above formula and RMC 4-2-115E3. (Ord. 6002, 12-14-2020)

C. REQUIREMENTS:

WINDOWS AND DOORS: Windows and front doors are an integral part of the architectural character of a home and, when they incorporate architectural elements of the home, they contribute to the overall balance and integration of the building form. Additionally, when they represent a significant amount of the facade of a home, they amplify the sense that the community is oriented to people.

Guidelines: Windows and doors shall serve as an integral part of the character of the home. Primary windows shall be proportioned vertically rather than horizontally. Vertical windows may be combined together to create a larger window area. Front doors shall be a focal point of the dwelling and be in scale with the home. All doors shall be of the same character as the home and architecturally consistent with the doors on the primary structure.

Standards:

 

R-10 and R-14

All of the following are required for new ADU construction:

 

 

 

1.

Primary windows shall be proportioned vertically, rather than horizontally;

 

 

 

2.

Vertical windows may be combined together to create a larger window area;

 

 

 

3.

All doors shall be made of wood, fiberglass, metal, or glass and trimmed with three and one-half inches (3 1/2") minimum head and jamb trim around the door;

 

 

 

4.

Sliding glass doors are not permitted along a frontage elevation or an elevation facing a pedestrian easement.

SCALE, BULK, AND CHARACTER: Residential communities are intended for people and homes that have appropriate scale and bulk to contribute to the sense of orientation to people.

Guidelines: The ADU shall visually demonstrate that it is accessory, or subordinate, to the primary structure by its reduced scale and bulk.

Standards:

 

R-4, R-6, R-8, R-10, and R-14

The ADU shall be architecturally compatible with significant architectural details of the primary structure, dominating forms, and design elements, such as eaves, roof pitch, roof form, porches, principal dormers, materials, and other significant architectural features.

EAVES: The design of eaves and overhangs act as unifying elements in the architectural character of a home. When sized adequately and used consistently, they work to create desirable shadows that help to create visual interest especially from blank, unbroken wall planes.

Guidelines: Eaves should be detailed and proportioned to complement the architectural style of the home.

Standards:

 

R-4, R-6, and R-8

Both of the following are required:

 

 

1.

Eaves projecting from the roof of the entire building at least twelve inches (12") with horizontal fascia or fascia gutter at least five inches (5") deep on the face of all eaves, and

 

 

2.

Rakes on gable ends must extend a minimum of two inches (2") from the surface of exterior siding materials.

 

R-10 and R-14

The following is required: Eaves shall be at least twelve inches (12") with horizontal fascia or fascia gutter at least five inches (5") deep on the face of all eaves.

ARCHITECTURAL DETAILING: Architectural detailing contributes to the visual appeal of a home and the community. It helps create a desirable human scale and a perception of a quality, well-designed home.

Guidelines: The ADU shall visually demonstrate a clear relationship with the primary structure so that the two (2) structures are architecturally compatible. Architectural detail shall be provided that is consistent with the architectural character of the primary structure; detailing like materials and color, fenestration, trim, columns, eaves, and/or corner boards shall reflect the architectural character of the primary structure.

Standards:

 

R-4, R-6, and R-8

If one siding material is used on any side of the dwelling that is two (2) stories or greater in height, a horizontal band that measures at least eight inches (8") is required between the first and second story.

Additionally, one of the following is required:

 

 

 

1.

Three and one-half inches (3 1/2") minimum trim surrounds all windows and details all doors; or

 

 

 

2.

A combination of shutters and three and one-half inches (3 1/2") minimum trim details all windows, and three and one-half inches (3 1/2") minimum trim details on all doors.

 

R-10 and R-14

All of the following are required:

 

 

 

1.

Three and one-half inches (3 1/2") minimum trim surrounds all windows and details all doors;

 

 

 

2.

At least one of the following architectural details shall be provided on each home: shutters, knee braces, flower boxes, or columns;

 

 

 

3.

Where siding is used, metal corner clips or corner boards shall be used and shall be at minimum two and one-half inches (2 1/2") in width and painted. If shutters are used, they shall be proportioned to the window size to simulate the ability to cover them; and

 

 

 

4.

If columns are used, they shall be round, fluted, or strongly related to the home’s architectural style. Six inches by six inches (6" x 6") posts may be allowed if chamfered and/or banded. Exposed four inches by four inches (4" x 4") and six inches by six inches (6" x 6") posts are prohibited.

MATERIALS AND COLOR: The use of a variety of materials and color contributes to the sense of diversity of housing stock in the community.

Guidelines: The ADU shall have a consistent design with the primary structure, including but not limited to the use of the same building materials and color.

 

R-4, R-6, and R-8

The ADU shall be of the same building material and color as the primary structure.

Where masonry siding is proposed at the edge of a facade, it shall also extend along the adjoining facade no less than twenty four inches (24"), measured horizontally from the corner of the structure.

Additionally, one of the following is required:

 

 

 

1.

A minimum of two (2) colors (body with different color trim is acceptable), or

 

 

 

2.

A minimum of two (2) differing siding materials (horizontal siding and shingles, siding and masonry or masonry-like material, etc.). One alternative siding material must comprise a minimum of thirty percent (30%) of the street-facing facade.

GARAGES: The minimization of the visual impact of garages contributes to creating communities that are oriented to people and pedestrians, as opposed to automobiles.

Guidelines: The visual impact of garages shall be minimized, while porches and front doors shall be the emphasis of the front of the home. Garages shall be located in a manner that minimizes the presence of the garage and shall not be located at the end of view corridors. Alley access is encouraged. If used, shared garages shall be within an acceptable walking distance to the housing unit it is intended to serve.

Standards:

 

R-4, R-6, R-8, R-10, and R-14

To ensure adequate vehicular maneuvering area, ADUs that incorporate a garage/carport shall have an obstruction-free area (inclusive of an alley) for a length based on the width of the garage doors:

 

 

 

1.

Nine-foot (9') garage doors shall be at least twenty-six feet (26') from the adjacent property line; or

 

 

 

2.

Sixteen-foot (16') garage doors shall be at least twenty-four feet (24') from the adjacent property line.

 

R-4, R-6, and R-8

If an attached garage is wider than twenty six feet (26'), at least one garage door shall be recessed a minimum of four feet (4') from the other garage door.

The garage doors contain a minimum of thirty percent (30%) glazing, architectural detailing (e.g., trim and hardware), and are recessed from the front facade a minimum of five feet (5'), and from the front porch a minimum of seven feet (7').

(Ord. 5960, 12-9-2019)