03-09-26-WS - Laserfiche WebLink

Home Browse Search

Creating for Understandings an ADU Zoning Code The ADU section of a community's zoning code needn't be overly complicated. it just needs to establish clear, objective and fair rules for the following: 1. A Definition: A good zoning code clearly defines its terminology. Here, for example, is a useful outline for what, in the real world, is a very fluid term: "An ADU is a smaller, secondary home on the same lot as a primary dwelling. ADUs are independently habitable and provide the basic requirements of shelter, heat, cooking and sanitation." 2. The Purpose: This is where the code describes key reasons a community allows ADUs. They should: • increase the number of housing units while respecting the style and scale of the residential neighborhood • bolster the efficient use of existing housing stock and infrastructure • provide housing that's affordable and responds to the needs of smaller, changing households • serve as accessible housing for older adults and people with disabilities 3. Eligibility: Who can build an ADU and on what type of lot? A statement in this part of the code clarifies that an ADU can be placed only on a "residentially zoned lot." (Some communities provide lot size standards.) 4. Creation: The code sets out how an ADU can be built. For instance: "An ADU may be created through new construction, the conversion of an existing structure, as an addition to an existing structure or as a conversion of a qualifying existing house during the construction of a new primary dwelling on the site" S. Quantity: Most municipalities that permit ADUs allow one per lot. Those allowing two typically permit one internal and one external. Some allow duplexes or townhomes to have an ADU, either in the backyard or on the ground floor. 6. Occupancy and Use: A code should state that the use -and -safety standards for ADUs match those used for the main dwelling on the property. (See page 17 for more.) Visit AARP.org/ADU to download Accessory Dwelling Units: Model State Act and Local Ordinance, a free publication that can be used by state and local officials to develop ADU policies. 7. Design Standards: Size and height: A zoning code might specify exactly how large and tall an ADU is allowed to be. For instance: "An ADU may not exceed 1,000 square feet or the size of the primary dwelling, whichever is smaller." Codes often limit detached ADUs to 1.5 or 2 stories in height. An example of that language: "The maximum height allowed for a detached ADU is the lesser of 25 feet at the peak of the roof or the height of the primary dwelling." Parking: Most zoning codes address the amount and placement of parking. Some don't require additional parking for ADUs, some do, and others find a middle ground — e.g., allowing tandem parking in the driveway and/or on -street parking. (See page 16 for more about parking.) Appearance: Standards can specify how an ADU's roof shape, siding type and other features need to match the primary dwelling or neighborhood norms. Some codes exempt one-story and internal ADUs from such requirements. (See page 16 for more.) 8. Additional Design Standards for Detached ADUs: • Building setbacks: Many communities require detached ADUs to either be located behind the primary dwelling or far enough from the street to be discreet. (A code might exempt preexisting detached units that don't meet that standard.) Although such a rule can work well for neighborhoods of large properties with large rear yards, communities with smaller lot sizes may need to employ a more flexible setback -and -placement standard. • Building coverage: A code will likely cap the combined lot coverage of a detached ADU and the primary dwelling to a specific percentage. • Yard setbacks: Most communities have rules about minimum distances to property lines and between buildings on the same lot. ADUs are typically required to follow the same rules. ■ The ABCs of ADUs A A R P 15