Agenda - Planning Commission - 08/02/2012

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in mind that the general standard for new development inside the greater Portland metropolitan service boundary is 10 to 12 dwelling units per acre. The ADU ordinance is designed to help achieve that density. For an existing house the ADU can be no more than 75 percent of the total living area of the house ora maximum of800 square feet, whichever is less. To keep detached ac- cessory dwellings inconspicuous, a unit must be at least 6o feet from the front property line, or the unit must be at least six feet be- hind the house, row house, or manufactured ADU and ;Garage Addition - Front • 5' side yard setback 20' rear yard setback • Parking in garage and driveway City of Cruz, California home. For fire safety, the detached ADU must be at least six feet from the primary dwelling. Portland does not require additional on -site parking for an accessory dwelling. Thus, on- street parking can be used. Design review is required if changes are proposed to the exterior of an existing house. The height limit for a detached acces- sory dwelling unit is 18 feet. The lot coverage of the detached accessory dwelling unit cannot exceed the lot coverage of the pri- mary dwelling. Together, the two dwellings cannot cover more than 15 percent of the entire lot. As for design, the exterior of the accessory dwelling unit must be the same as or visually match the primary dwelling. For instance, the roof pitch of the acces- sory dwelling must be same as the pitch for the primary dwelling, and the trim and the windows should match. Unfortunately, though, the ordinance does not contain any graphics for the reader to follow in trying to understand the design standards. Finally, Portland requires that an applicant for an ADU submit a site plan, ADU and Garage Addition -Side • 5' side yard setback • 20' rear yard setback • Parking in garage and driveway 'ADU: and GarageAdditien —Rear 5 side yard setback. • 20 tear yard, setb • :Parking in garagerand driveway One Story Backyard Addition • 5' side yard setback • 20' rear yard setback a Parking in :garage and driveway e These illustrations show a range of attached ADU types. Attached ADUs maybe preferable for housing extended family members. architectural plans, and structural plans. From 2002 through 2011 Portland issued a total of 316 accessory dwelling per- mits. The downturn in the national economy was also reflected in ADU activity. In 2007, 31 permits were issued; only 19 were issued in 2008 and 22 in 2009. The Portland City Council then enacted a waiver of the system development charges for three years for new accessory dwelling units. The new policy seems to be working. In 2010, the city is- sued 61 permits; in 2011, 64. Most of the new ADUs have been built on the east side of the city fairly close to downtown. About 40 percent of the ADUs built have been detached cottage units and 6o percent attached apartments, typically above a garage. Spokane, Washington Spokane has taken a unique approach to accessory dwellings by adopting a cottage housing ordinance in 2006. Although this ordinance may not be applied as widely as a typical accessory housing ordinance, it offers a way to increase density and affordability through the construction of small houses. The purpose of the Spokane ordinance is to "support the diversity of housing, increase the variety of housing types for smaller households and pro- vide the opportunity for small, detached single- family dwelling units within existing neighborhoods." The cottage ordinance applies in the city's single- family residential district and the residential agricultural district. The ordinance requires a minimum of half an acre and a minimum of six units, with a maximum of12 units, and offers the property owner a zo percent density bonus. Properties that meet the minimum acreage standard are most often on the edge of a city, and hence the cottage ordinance could be especially helpful as a city with annexa- tion powers adds land within the city limits. The maximum square footage is 1,000 square feet, excluding any floor area where the floor -to- ceiling height is less than six feet. But half of the cottages can have no more than 65o square feet on the main floor and half can have no more than 1,000 square feet on the main floor. Once a cot- tage is built, it cannot be expanded. Maximum lot coverage is 40 percent. The height limit is 18 feet, except if the dwell- ing has a pitched roof. Then the maximum height is 25 feet. All cottages are required to have covered porches, which are oriented toward common open space or to the street. For each cottage there must be at least 250 square feet of common open space and 250 square feet of private open space. The com- mon open space must be landscaped and maintained by a home owners association. Setbacks for all structures from the property lines must average 10 feet but cannot be less than five feet, and not less than 15 feet from a public street. This last is similar to the front yard setback required of any detached single- family residence. ZONINGPRACTICE 7.12 AMERICAN PLANNING ASSOCIATION i page 5