Unified Development Ordinance

Sec. 2.6.3. Accessory Dwelling

Sec. 2.6.3. Accessory Dwelling aaron.sheppard… Tue, 05/23/2023 - 09:44
  1. Purpose and Objectives
    The Accessory Dwelling housing pattern provides for the development of an accessory dwelling unit or units on a lot with an existing Detached House or Tiny House as an accessory use to a principal use of Single-unit Living, or on a lot with an existing Attached House, Townhouse or Tiny House as an accessory use to a principal use of Two-unit Living, or on a lot developed with an existing Townhouse as an accessory use to a principal use of Multi-unit Living.
  2. Base Standards Apply
    Except as specifically set forth in this section, the allowed uses, the dimensional requirements, height limits and general development standards of the underlying zoning district apply.
  3. Definition
    An Accessory Dwelling Unit (ADU) is a self-contained dwelling unit that is located on the same lot as a principal dwelling that meets the regulations identified in Section 2.6.3.D. An Accessory Dwelling Unit may be located above a garage. Accessory Dwelling Units may be detached, attached, or internal to the principal dwelling. Only residential uses are permitted in Accessory Dwelling Units with the exception that a Live-Work use, as defined in Sec. 6.7.3.E., may be allowed in an ADU so long as that is the only Live-Work use present on the lot. The Live-Work use must meet the definition of an accessory use to the principal residential use on the lot as described in Sec. 6.7.1.
  4. Accessory Dwelling Unit Regulations
    In accordance with this section, an accessory dwelling unit shall conform with the following development regulations:
    1. An ADU shall be located on the same lot as a principal dwelling and meet both of the following:
      1. The gross floor area of the accessory dwelling shall be less than the gross floor area of the total principal dwelling; and
      2. Shall be affixed to or constructed on a permanent foundation and not be a manufactured home or moveable structure except as specified in Sec. 2.6.3.D.6. below.
    2. There shall be no more than one ADU on the same lot as a principal dwelling unless it is located in a Frequent Transit Area as shown on the City’s Comprehensive Plan which would then allow for up to two ADUs on the same lot as a principal dwelling. However, in the Frequent Transit Area, only one ADU can be attached to the principal dwelling. In the case of a townhouse development only one ADU is permitted per townhouse lot whether within a Frequent Transit Area or not;
    3. It shall be accessed by a lockable external entrance;
    4. Ownership of an ADU shall not be transferred apart from its principal dwelling unit;
    5. It shall meet all relevant standards and requirements of the UDO, provided however accessory dwelling units shall not be subject to Sections 6.7.1. and 6.7.2. with the exception of 6.7.2.B.
    6. An Accessory Dwelling Unit may be a Manufactured Home as defined in Article 12.2 if it meets all of the following:
      1. The predominant roofline shall have a pitch of 5:12 or greater.
      2. The eave projections of the roof must not be less than ten inches (excluding roof gutters) unless the roof pitch is 8:12 or greater.
      3. The minimum height of the first-story exterior wall must be at least seven feet, six inches.
      4. Materials used as exterior wall covering shall be of a non-reflective material.
      5. Foundation skirting shall comply with the requirements set forth in Section 4.5.3.D.
      6. The Manufactured Home is no greater than 600 square feet in gross floor area.
    7. Unless attached thereto by a common wall, an ADU must be separated by at least 6’ from any other building on the lot.
    8. All ADU entrances must be externally accessible by pedestrians from either the driveway, street and/or alley from which the lot takes access.
    9. ADUs are not permitted on Flag Lots.
    10. Encroachments into setbacks are permitted pursuant to Section 1.5.4.D.
    11. Vertical encroachments are permitted pursuant to Sections 1.5.7.D.2. and 1.5.7.D.3.g.
      2-6-3-accessory-dwelling-1
      2-6-3-accessory-dwelling-2
  5. Description An Accessory Dwelling Unit (ADU) is a self-contained dwelling unit that is located on the same lot as a principal dwelling that meets the regulations identified in Section 2.6.3.D. An ADU may be located above a garage. ADUs may be detached, attached, or internal to the principal dwelling. Only residential uses are permitted in ADUs.
  6. Districts Allowed In
    R-1, R-2, R-4, R-6, R-10
  7. Building Specifications
    Lot Area   Greater than 40,000 sf 10,000 sf to 40,000 sf Less than 10,000 sf
    G1 Gross Floor Area (max)1 1,000 sf 800 sf 800 sf
  8. Detached ADU Setbacks
    Lot Area   Greater than 40,000 sf 10,000 sf to 40,000 sf Less than 10,000 sf
    H1 From primary street (min) Must be located at or behind the front wall of the house.
    H2 From side street (min) 20' 20' 10'
    H3 From side lot line (min)2 10' 5' 5'
    H4 From rear lot line (min)3 10' 5' 5'
    H5 From alley (min) 4' without parking / 20' with parking 4' without parking / 20' with parking 4' without parking / 20' with parking
  9. Height
    Lot Area   Greater than 40,000 sf 10,000 sf to 40,000 sf Less than 10,000 sf
    I1 Overall height (max) 26' 26' 26'
    1Gross floor area shall include all conditioned space. Attached unconditioned space shall be included in the calculation of accessory structure floor area.
    2For townhouse lots, H3 shall only apply to the side site boundary.
    3For townhouse lots, H4 shall only apply to the rear site boundary.