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Sustainability Code Amendment Project- ADUs Page 1 September 2010 Accessory Dwelling Units- Fact Sheet Definition An Accessory Dwelling Unit (ADU) is a residential unit that is located on the same lot as a single-family dwelling unit, either internal to a single family dwelling, attached to a single family unit (such as in an addition) or in a detached structure (such as in a garage or separate accessory structure). The Accessory Dwelling Unit must be a complete housekeeping unit with a shared or separate entrance, kitchen, sleeping area, closet space, and bathroom facilities. Background Accessory Dwelling Units (ADUs) have become an important component of the housing stock in many communities - both large and small – in the United States. By providing housing on existing lots in developed neighborhoods, ADUs are a form of land use that makes good use of land and public infrastructure investment. Accessory Dwelling Units, when located near employment and retail centers, help increase use of circulation alternatives (such as walking, cycling, mass transit) leading to a reduction in green house gas emissions and energy (fuel) use. Additionally, the changing face of the American public and its housing needs supports the inclusion of ADUs as a housing alternative. More people are aging, are “empty nesters”, and desire to down-size. In addition, the work force continues to be challenged to find affordable housing and ADUs can help address that demand. ADU within existing structure ADU in standalone structure ADU above garage ---PAGE BREAK--- Sustainability Code Amendment Project- ADUs Page 2 September 2010 Purpose Statement The purposes of the proposed Accessory Dwelling Unit regulations are to: 1. Create new housing units while respecting the look and scale of single-family dwelling development; 2. Increase the housing stock of existing neighborhoods in a manner that is less intense than alternatives; 3. Allow more efficient use of existing housing stock, public infrastructure, and the embodied energy contained within existing structures; 4. Provide a mix of housing that responds to changing family needs and smaller households; 5. Offer a means for residents, particularly seniors, single parents, and families with grown children, to remain in their homes and neighborhoods, and obtain extra income, security, companionship, and services; 6. Promote a broader range of accessible and more affordable housing; 7. Provide opportunity for workforce housing in developed and new neighborhoods, close to places of work, thus reducing greenhouse gas emissions and reducing fossil fuel consumption through less car commuting; 8. Support transit-oriented development and reduce auto usage by increasing density near transit stops; and 9. Support the economic viability of historic properties and the city’s historic preservation goals by allowing accessory residential uses in historic structures. General Concepts Regulations to ensure mitigation of negative impacts 1. Limit Size of ADU: Proposal is to limit the size of an Accessory Dwelling Unit to ensure it is subordinate to the principal structure. The regulation would limit the size to 50% of the square footage of the principal structure or 650 square feet; whichever is greater. 2. Require Owner Occupancy: Require either the principal unit or the ADU to be occupied by the owner of the lot. The idea is that if an owner is on site, they are more likely to ensure tenants are not causing problems (such as noise, etc.) and will ensure the property is maintained. 3. Limit ADUs to one ADU per lot. 4. Require ADUs to be registered / licensed with City. 5. Parking- one stall per ADU. As written, parking would be required but the Transportation Division could modify the requirement (such as allow Tandem Parking or no Parking) where certain factors are evident (such as there is available on-street parking, it is within ¼ mile of a Trax Station, it is within walking distance to a Business District area, etc.) 6. Home occupations (such as an office) allowed in an ADU, but conditional home occupations (such as music lessons or hair styling) where person would come to house would not be allowed in the ADU. ---PAGE BREAK--- Sustainability Code Amendment Project- ADUs Page 3 September 2010 7. Must meet height, setback and building coverage for the principal structure regulations of the zoning district. 8. Entrances for an ADUs must be to the back or side of the property. This is to enforce the subordinate nature of the unit. General Questions 1. Where to Allow? In what zoning districts should Accessory Dwelling Units be allowed? a. Should they only be allowed in single-family zoning districts? i. Could they be allowed in local historic districts to help off-set cost of preservation (incentive)? ii. Could they be allowed near Light Rail Transit Stations or within walking distance of a business area? iii. Could they be allowed on multi-family zoned properties, with single- family homes, where the lot is too small to allow anything but a single family unit? iv. Should they only be allowed on single-family residential lots where the size of the lot meets a minimum square footage? v. Are there certain neighborhoods where a “pilot program” could be started to gauge demand / impacts? 2. Design Guidelines Should there be design guidelines for detached ADUs? a. Such as exterior materials, roof pitch, window patterns, etc to ensure compatibility with house design. b. We currently do not have these types of design standards within the City except within designated local historic districts.