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- Step 3: Does my ADU meet zoning requirements?
Step 3: Does my ADU meet zoning requirements?
An example of the types of "Accessory Dwelling Units" permitted under revised Woodland Ordinances. (2020). Daily Democrat. https://www.dailydemocrat.com/2020/01/08/woodland-updates-its-granny-flat-ordinance-to-comply-with-new-state-law/
ADUs can be detached, attached, or a conversion of an existing space.
For conversion of existing structures (such as garages, workshops, guest quarters, or portions of a primary dwelling), upgrades to meet Building Code may be required, especially if the structure was not originally meant to be inhabited.
SIZE REQUIREMENTS:
Detached: Up to 1,200sqft of interior livable space.
Attached: Up to 1,200sqft of interior livable space, not to exceed 50% of the size of the primary dwelling. This will not exclude an ADU that is up to 800sqft, 16ft in height, with side & rear setbacks of at least 4ft.
Converted: Must be within the space of an existing or proposed primary dwelling or within the space of an existing accessory structure, plus up to 150 additional square feet if the expansion is limited to accommodating ingress and egress.
HEIGHT REQUIREMENTS:
Detached ADUs: Up to 16ft in height, with the following exceptions:
- May be up to 18 feet in height if located on a site with an existing or proposed multifamily dwelling that has more than one story.
- May be up to 18 feet in height if within 1/2 mile walking distance of a major transit stop or high quality transit corridor, and may have two additional feet in height (up to 20 feet) if necessary to match the roof pitch of the primary dwelling.
- A unit above a detached structure that is contiguous to an alley may be up to 25ft in height.
Attached: Up to 25ft in height or the same height set by the zoning code for the primary dwelling, whichever is less.
Converted: Up to the height of the existing structure being converted.
SETBACK REQUIREMENTS:
Detached ADUs that meet the requirements in Gov. Code Section 66323 and that are eligible for building-permit only review must be at least four feet from side and rear property lines. All other ADUs must meet the requirements below:
Detached: 20ft front yard setback or the front setback imposed by the underlying zone, whichever is greater. At least 4ft side and rear yard setbacks.
Attached: 20ft front yard setback or the front setback imposed by the underlying zone, whichever is greater. At least 4ft side and rear yard setbacks.
Converted: No setback shall be required for a legally established, ADU conversion of a portion of the primary dwelling, existing garage or accessory building.
Corner Lots: Side yard setbacks may be increased up to 10ft to allow for Public Utility Easements.
Exceptions:
- Side or rear yard setbacks adjacent to an alley or non-residentially zoned property may be zero feet. Parking provided off the alley shall maintain a 24-foot back-out (including the alley width).
LOT COVERAGE REQUIREMENTS:
Lot coverage requirements do not apply to ADUs or JADUs that meet the requirements of Government Code Section 66323, and do not apply to ADUs less than 800 square feet of interior livable space in size, 16ft or less in height, with side and rear setbacks of at least 4ft. For all other ADUs:
Lot Coverage: An attached or detached ADU may not cause the total lot coverage of the single family lot to exceed 50%.
Rear Lot Coverage: An attached or detached ADU shall not result in more than 30% rear yard coverage as measured from the rear wall of the primary residence to the rear property line.
ADDITIONAL REQUIREMENTS
These requirements shall apply only to new attached or detached ADUs over 800 square feet of interior livable space in size.
Architectural Requirements:
- The ADU must have an independent exterior entrance, apart from that of the primary dwelling.
- The exterior lighting must be limited to down-lights or as otherwise required by the building or fire code.
- The interior horizontal dimensions of an ADU must be at least 10 feet wide in every direction, with a minimum interior wall height of seven feet.
- A garage converted to an accessory dwelling unit shall include removal of garage door(s) which shall be replaced with architectural features, including walls, doors, windows, trim and accent details.
- Access stairs, entry doors and decks must face the primary residence or the alley, if applicable.
- All second-story windows and doors in a second unit that are less than 30 feet from a property line that is not a right-of-way line must either be (for windows) clerestory with the bottom of the glass at least six feet above the finished floor, or (for windows and for doors) utilize frosted or obscure glass.
- The architectural treatment of an ADU to be constructed on a lot that has an identified historical resource listed on the California Register of Historical Resources must comply with all applicable ministerial requirements imposed by the Secretary of Interior.
Landscape and Screening Requirements:
Required for ADUs needing a ZAP and strongly suggested for ADUs needing a building permit or ADU permit.
- All landscaping must be drought-tolerant.
- Evergreen landscape screening must be planted and maintained between the ADU and adjacent parcels when there is direct adjacency of the ADU to an existing primary dwelling on an adjacent parcel in which there is no screening as follows:
- At least one 5-gallon size plant shall be provided for every five linear feet of exterior wall.
- As an alternative, a solid fence of at least six feet in height may be installed along a side or rear yard in compliance with fencing standards.
Parking Requirements:
- One off-street parking space is required per ADU or per bedroom, whichever is less.
- ADUs requiring parking spaces may be located in setback areas or tandem parking on an existing driveway.
- Each unenclosed parking space shall be at least 8.5 feet x 18 feet in size. Parking in an enclosed garage must be at least 10 feet x 20 feet and have at least 7.5 feet of vertical clearance.
- ADU garage conversions are not required to replace the lost parking spaces.
- Exceptions: Parking is not required when the ADU is located within one-half mile walking distance of public transit, is located in a historic district, on-street parking permits are required but not offered to the occupant of the ADU, there is a car share vehicle located within one block of the ADU, or the ADU is part of the proposed or existing primary residence or an accessory structure.
- Public transit is a location, including, but not limited to, a bus stop or train station, where the public may access buses, trains, subways, and other forms of transportation that charge set fares, run on fixed routes, and are available to the public.
Solar Requirements:
- All newly constructed detached ADUs must have solar.
- Some exclusions apply. Contact the Building Division at (530) 661-5820 for further details.
- Solar may be placed on the ADU or primary dwelling.
Fire Sprinkler Requirements:
- Fire sprinklers are required in an ADU if sprinklers are required in the primary residence.
- The construction of an ADU does not trigger a requirement for fire sprinklers to be installed in the existing primary dwelling.
Requirements:
- Tiny homes, manufactured, or modular homes are permitted for use as ADUs, provided that they comply with all building standards and are mounted on permanent foundations.