A. Maximum Building Height: Maximum building heights for ADUs are:
1. Thirty two feet (32') when built within the building envelope for the principal structure.
2. One story ADU structure: Eighteen feet (18') when built in the rear yard.
3. ADU above a detached garage: Twenty four feet (24') when built in the rear yard over a garage and must meet the second story step back requirement as provided in subsection M of this section.
4. Railing, parapets, equipment, and other similar structures/fixtures/architectural elements are included in the maximum height.
B. Setbacks: Setbacks for ADUs are:
1. Setbacks for ADUs in the principal building envelope are:
a. Front: The front yard requirement shall be twenty feet (20').
b. Side, Interior: The interior side yard requirement shall be five feet (5'). If there is no alley or other legal access behind a lot, each lot shall have at least one side yard of ten feet (10') minimum.
c. Side, Street: The street side yard requirement shall be ten feet (10').
d. Rear: The rear yard shall be twenty five feet (25') from the rear property line.
2. Setbacks for ADUs located in the rear twenty five feet (25') of a lot:
a. Side Yard: Shall be at least five feet (5') from the side lot line.
b. Rear Yard: Shall be at least five feet (5') from the rear lot line.
(1) Lots With An Alley: Lots with an alley in the rear of the lot may have a setback of three feet (3') from the rear property line.
(2) Rear Yard Exception: A detached ADU may encroach up to three feet (3') beyond the twenty five foot (25') rear yard and still maintain the above stated requirements, provided the detached structure does not exceed the maximum height set out in subsection A of this section and meets the second story step back requirements of subsection M of this section.
C. Parking: One additional parking space beyond that required for the principal dwelling is required for an ADU.
D. Owner Occupancy: Either the principal dwelling unit or the accessory dwelling unit must be occupied by a majority owner of the property if a unit is used as a short-term or vacation rental. "Owner occupied" means that a property owner, as reflected in title records, makes his or her legal residence at the site, as evidenced by voter registration, vehicle registration, or similar means, and physically resides at the site more than six (6) months out of any given calendar year.
E. Number Of Occupants: One accessory dwelling unit is permitted as subordinate to an existing single-family dwelling; provided the total number of occupants in both the principal dwelling unit and accessory dwelling unit combined does not exceed the maximum number established for a "family" as defined in section
17.02.055 of this title.
F. Subdivision: An accessory dwelling unit shall not be subdivided or otherwise segregated in ownership from the principal dwelling unit.
G. Size And Scale: The accessory dwelling unit shall meet the following:
2. Maximum size shall be eight hundred (800) square feet (finished area; does not include unfinished basements).
3. An ADU shall not exceed seventy five percent (75%) of the total square footage of the primary dwelling unit, excluding the garage area.
H. Location: The accessory dwelling unit may be added to or included within the principal unit, including a basement, or located in a detached structure. Other Code standards apply.
I. Entrances For ADUs Attached To Principal Unit: The single- family dwelling containing the accessory dwelling unit shall have only one entrance on each front or street side for the ADU.
J. Additions: Additions to an existing structure for the purpose of developing an accessory dwelling unit shall be designed consistent with the existing roof pitch, siding, and windows of the principal dwelling unit.
K. Conversion Of Existing Detached Structures/Garages/Sheds: Any existing detached structure may be converted into an accessory dwelling unit provided it meets the following:
1. The structure meets the current adopted Building Code and a building permit can be issued.
2. The structure is not over the property line or in the City's right-of-way.
3. The structure complies with current building and zoning standards if it is to be expanded.
4. The structure cannot be expanded outward or upward, regardless of the provisions of the Non-Conforming Code, without complying with current standards.
5. An existing garage with a valid building permit and a height between eighteen feet (18') and twenty five feet (25') may be converted into an ADU if it can meet the requirements of subsection K1 of this section.
L. Short-Term Rentals: If an accessory dwelling unit (ADU) is going to be used for less than 30-day stays, the owner shall comply with the rules of short-term rental requirements in chapter 17.08, article X of this title.
M. Second Story Step Back: Required for attached and detached ADUs in the rear yard. A newly constructed or second-story addition to an existing structure within the rear yard must have second story step backs that meet the following requirements:
1. The upper step back begins at a height of ten feet (10') on the interior side property line and at fifteen feet (15') on the rear yard property line (see figures below).
2. The step back is at 1:1 measurement, which equates to a forty five degree (45°) angle.
3. A building permit application must show all dimensions, setbacks, and step backs as shown in the figures below.
4. There is no second story step back requirement on the street side of a corner lot.
5. Eaves are allowed to project two feet (2') into the step back air space.
SIDE YARD SECOND STORY STEP BACK
SIDE YARD SECOND STORY STEP BACK, 2 FOOT EAVE PROJECTION ALLOWED
SIDE YARD SECOND STORY STEP BACK, ROOF PROJECTION NOT ALLOWED
SIDE YARD SECOND STORY STEP BACK, NOT ALLOWED
REAR YARD SECOND STORY STEP BACK, WITH ALLEY
REAR YARD SECOND STORY STEP BACK, NO ALLEY
N. Lot Coverage/Open Spaces And Pervious Surface Requirement:
1. A thirty percent (30%) pervious surface is required for all lots with an ADU.
2. Pervious surfaces include such things as grass, Astro Turf, pavers, grasscrete, gravel, and decking materials (unless there is a concrete or impervious surface below).
3. There is no dimensional requirement or requirement for a certain type or quantity of landscaping/trees (other than the standard street tree requirements).
4. The building permit application must show all pervious areas on the lot and the calculation of a separate plan titled "Lot Coverage/Pervious Surface Plan". (Ord. 3674 §7, 2021: Ord. 3639, 2019)