(a) 
The purpose of this chapter is to prescribe development and site regulations that apply, except where specifically stated, to Urban Dwelling Units (UDUs). This chapter is intended to implement Government Code Section 65852.21, as amended from time to time. Implementation of this section is meant to expand housing opportunities by increasing the number of smaller units available within existing neighborhoods while meeting statewide housing goals and responding to wildfire and wastewater constraints.
(b) 
The City recognizes opportunities to implement policies and programs of the Atascadero General Plan housing element providing for, and regulating, expanded housing opportunities for all persons within the community.
(c) 
Implementation of this chapter is meant to expand housing opportunities for very-low, low and moderate-income and/or elderly households by increasing the number of affordable by design and rental units available within existing neighborhoods.
(Ord. 657 § 2, 2022)
As used in this chapter:
Accessory Dwelling Unit (ADU).
ADUs are defined by Government Code Section 65852.2 to mean an attached or detached residential dwelling unit that provides complete independent living facilities for one or more persons. ADUs shall include permanent provisions for living, sleeping, eating, cooking, and shall have a bathroom, and shall be located on the same parcel as the single-family or multifamily dwelling per the standards set forth in this section. An accessory dwelling unit also includes an efficiency unit as defined in Section 17958.1 of the Health and Safety Code and a manufactured home as set forth in Section 18007 of the Health and Safety Code.
Existing Structure.
For the purposes of this chapter and implementation of Government Code Section 65852.21, an existing accessory structure or existing primary structure is defined as a structure, or the confines of a structure, that has received a passed final inspection prior to January 1, 2020.
Guesthouse.
Guesthouses are defined as residential occupancy construction (R) structures permitted prior to 2004 with a full bathroom, partial kitchen, and are the same as a residential dwelling unit for the purposes of defining use and calculating fees.
Individual Property Owner.
A natural person holding fee title individually or jointly in the person's own name or a beneficiary of a trust that holds fee title. This does not include any corporation or corporate person of any kind (partnership, limited partnership, limited liability company, C corporation, S corporation, etc.) except for a community land trust (as defined by Revenue and Taxation Code Section 402.1(a)(11)(C)(ii)) or a qualified non-profit corporation (as defined by Revenue and Taxation Code Section 214.15).
Junior Accessory Dwelling Unit (JADU).
JADUs are defined by Government Code Section 65852.2 to mean a residential dwelling unit internal to an existing or new primary dwelling unit that provides complete independent living facilities for one or more persons. JADUs shall include permanent provisions for living and shall be located on the same parcel and within the same structure as the single-family dwelling. A junior accessory dwelling unit also includes an efficiency unit as defined in Section 17958.1 of the Health and Safety Code.
Primary Dwelling Unit.
A primary dwelling unit (primary unit) is a principal or urban dwelling unit.
Principal Dwelling Unit.
An existing or new proposed dwelling unit on a residential zoned legal lot of record permitted as allowed by the City's zoning and allowed density of the parcel and not constructed under the provisions for Chapter 5 or Chapter 18 of this title. Any additional existing units above the base residential density shall be considered an ADU or UDU. New units built as part of an SB 9 lot split shall not be considered a principal dwelling unit if a principal unit already exists on the parent parcel or new parcel that is created from the lot split.
Residential Single-Family Property.
A property zoned for single-family development with a base density of one dwelling unit per parcel.
Short-Term Rental:
Short-term rentals (vacation rental) shall be defined as rental units with stays of 30 consecutive calendar days or less per individual or party.
Urban Dwelling Unit (UDU).
A primary dwelling unit established or proposed to be developed in accordance with the standards, procedures, and requirements set forth under Government Code Section 65852.21 and this chapter, either as a primary or second primary unit on a parcel.
Urbanized Area (UA).
An urbanized area is a census boundary designated by the US Census Bureau.
Urban Lot Split.
A lot split that divides one single-family parcel into two lots consistent with Government Code Section 65852.21 and consistent with Title 11.
(Ord. 657 § 2, 2022)
(a) 
Building Permit Required. A building permit application shall be required for the construction, occupancy or conversion of any UDU.
(b) 
Ministerial Review Process. An application for development of a UDU will be reviewed as a ministerial permit, without discretionary review or a hearing, if it meets all the requirements set forth in this section, and after payment of all applicable fees.
(c) 
Water Service. All UDUs shall be served by a public water system
(d) 
Wastewater Service. To avoid health and safety impacts to ground water quality and nitrogen loading, UDUs shall be served by the City sanitary sewer system when located on lots with a gross area less than one acre, except when:
(1) 
The parcel is three-quarters (0.75) gross acres or greater and all of the following criteria can be met:
(i) 
It can be demonstrated that all properties within a one-quarter (1/4) mile radius are of sufficient size, considering possible future lot splits and full development potential, to provide a minimum density of at least one-half (0.5) acres per unit within the one-quarter (1/4) mile radius.
(ii) 
It shall be demonstrated that a new or expanded on-site wastewater disposal system can accommodate the additional unit while meeting requirements of the City's Local Area Management Plan (LAMP).
(2) 
UDUs that do not meet the above requirements and do not have the ability to connect to City sewer must be served by an on-site wastewater system that includes pre-treatment and shall be subject to the approval of the City Engineer and must be approved and constructed in accordance with the City's LAMP standards
(e) 
The maximum amount of paving for parking and access for any principal, primary, accessory, and junior accessory unit in a front setback area is limited to 50% of the front yard setback area.
(f) 
Design. The design of an UDU shall be consistent with any objective design standards listed in this chapter.
(g) 
Short-Term Vacation Rental Prohibited. UDUs shall not be rented for terms of 30 days or less.
(h) 
Illegal Unit. The construction, establishment, or occupancy of an Urban Dwelling Unit that has not received a valid construction permit and is contrary to the provisions of this chapter is declared to be unlawful and shall constitute a misdemeanor and a public nuisance.
(i) 
Deed Notification Required. Prior to issuance of a building permit for the UDU, the individual property owner shall submit to the City a deed covenant for recordation with the County Recorder in a form approved by the Community Development Director, which shall run with the land and include at a minimum the following provisions:
(1) 
A prohibition on the sale of the UDU separate from the sale of the principal dwelling unit, unless a subsequent lot split is approved and recorded.
(2) 
A restriction on the size and attributes of the UDU that conforms with this Section
(3) 
A prohibition on using the UDU as a short-term rental.
(4) 
Owner occupancy requirements
(5) 
A statement that the restrictions shall be binding upon any successor owner of the property and that failure to comply with the restrictions shall result in legal action against the owner.
(Ord. 657 § 2, 2022)
(a) 
Location Requirements. An application for development of an urban dwelling unit must meet all the following location requirements:
(1) 
The subject parcel must be located in an area zoned for residential single-family use and be within or partially within the urbanized area, as designated by the US Census Bureau.
(2) 
The subject parcel must not be located in an area designated in Government Code Sections 65913.4(a)(6)(B) through (K). This includes, but is not limited to, certain farmland, wetlands, hazardous waste sites, earthquake fault zones, special flood hazard areas, regulatory floodways, lands identified for conservation, on a site with a historic resource, and within or adjacent to habitats for protected species.
(3) 
Number of UDUs.
(i) 
No more than two primary dwelling units may be developed on any parcel; and
(ii) 
Pursuant to the authority provided by Section 65852.21(f) of the Government Code, no urban dwelling unit shall be permitted on any lot in a single-family zoning district if: (1) an urban lot split has been approved pursuant to Title 11; and (2) two units (principal dwelling unit, UDU, ADU, or JADU) have already been approved for construction on either resulting lot; and
(iii) 
The maximum development of any dwelling units is shown below if no urban lot split has been recorded:
(iv) 
The maximum development of any dwelling units is shown below if an urban lot split has been recorded:
(v) 
If multiple units exist on a site that were constructed prior to designation as an accessory, junior accessory, or urban dwelling unit, those units must be designated as one of the permitted housing unit types prior to further development of the property.
(4) 
UDUs and urban lot splits shall not be allowed in Planned Developments.
(5) 
No UDUs shall be allowed inconsistent with the California Code of Regulations Section 1273.08.
(Ord. 657 § 2, 2022)
Standards for the development of UDUs shall be governed by this chapter. Each UDU shall be subject to compliance with the California Building Code and the following standards:
(a) 
Limitation on Demolition and Alterations. A proposed urban dwelling unit must not involve demolition or alteration of:
(1) 
Housing that is subject to a recorded covenant, ordinance, or law that restricts rents to levels affordable to persons and families of moderate, low, or very low income.
(2) 
Housing that is subject to any form of rent or price control through a public entity's valid exercise of its police power.
(3) 
Housing that has been occupied by a tenant in the last three years.
(4) 
More than 25% of the existing exterior structural walls, unless the housing has not been occupied by tenants within the last three years.
(b) 
Limitation on Parcels Withdrawn from Rental Market. A proposed urban dwelling unit must not involve property withdrawn from rental market pursuant to Government Code Section 7060 and following, within 15 years before the date that the development proponent submits an application.
(c) 
Development Standards. A proposed urban dwelling unit must comply with the following development standards:
(1) 
Maximum Size. The maximum size of UDUs shall be as follows:
(i) 
The maximum size of a proposed urban dwelling unit must not exceed 1,000 square feet in floor area.
(ii) 
Any dwelling unit other than the principal dwelling unit, that was established on the lot prior to the submittal of a complete application for a development pursuant to this chapter may not be altered or expanded to a size greater than 1,000 square-feet, exclusive of any attached garage, storage space, or enclosed porch. No additional unconditioned space can be added if greater than the maximum allowances described in subsection (c)(7) below. If existing units exceed the maximum size thresholds, no expansion or additions shall occur.
(2) 
Setbacks. Minimum setbacks shall be as follows:
(i) 
Primary street frontage: Twenty-five feet.
(ii) 
Secondary street frontage: Twelve and one-half (12.5) feet.
(iii) 
Corner street frontage: Ten feet.
(iv) 
Access way (flag or easement): Ten feet.
(v) 
Side: Five feet unless the unit is 16 feet or less in height, then the setback shall be reduced to four feet feet
(vi) 
Rear: Ten feet unless the unit is 16 feet or less in height, then the setback shall be reduced to four
(vii) 
No minimum setback is required for the conversion of an existing permitted structure or a structure constructed in the same location and to the same dimensions as an existing permitted structure.
(4) 
Height. All UDUs shall comply with the height limitations of the underlying zoning district except all units that are closer than 10 feet to the rear property line or five feet from a side property line shall be a maximum of 16 feet.
(5) 
Parking. There must be at least one off-street parking space per proposed urban dwelling unit unless specifically exempted by State law. If required parking spaces are eliminated as part of the construction of the UDU, replacement parking shall be required.
(6) 
Open Space. Private open space shall be provided for each residential unit at a ratio of 300 square feet for each unit that provides two or less bedrooms. Each bedroom in excess of two shall require an increase of private open space by 50 square feet. The required front yard setback area shall not be used to satisfy the open space requirement; however, side and rear setback areas, decks, and patios may be utilized. The minimum length and width of the private open space area shall not be less than 10 feet.
(7) 
Unconditioned Spaces. A garage or other unconditioned space may be attached to a UDU providing any attached space with a non-R occupancy shall be limited to 300 square-feet, except as follows:
(i) 
Any non-R occupancy space may be up to 500 square feet if it is on a different level than the UDU and used for vehicle parking and the entirety of the UDU is located on a different floor with the exception of an entry and stairs.
(ii) 
If an existing accessory structure is converted to an ADU and the size of the unconditioned space exceeds the maximum limit, the existing space can remain but may not be expanded.
(8) 
Second Story. Two story units built in accordance with urban dwelling unit standards shall have a second floor that is limited to 75% of the gross area of the first floor inclusive of any attached garage.
(9) 
Architectural Features: Use of at least five of the following architectural features on all street facing elevations, and at least three of the following architectural features on all interior and rear yard elevations, as appropriate for the building type and style, is required.
(i) 
Dormers;
(ii) 
Gable roof form;
(iii) 
Recessed entries (at least three feet);
(iv) 
Covered porch entries with a minimum projection of six feet;
(v) 
Cupolas or towers;
(vi) 
Pillars or posts;
(vii) 
Eaves (minimum 12 inch projection);
(viii) 
Off-sets in building face (minimum 16 inches);
(ix) 
Window trim;
(x) 
Bay or oriel windows;
(xi) 
Balconies;
(xii) 
A minimum of two decorative patterns on exterior finishes (e.g., scales/shingles, wainscoting, board and batten, and similar features); and
(xiii) 
Decorative cornices and roof lines (e.g., for flat roofs).
(10) 
Lot Coverage. Lot coverage of all primary dwelling units shall not exceed 40% of the net lot area.
(11) 
Storage and Laundry. Each unit shall include the following:
(i) 
Three hundred cubic feet of shelved storage area. (Bedroom and entry/coat closets shall not count toward this requirement);
(ii) 
Dedicated space for laundry facilities with hookups.
(12) 
Undergrounding of Utilities. All new utilities shall be installed underground, per Title 8.
(13) 
Driveways. Where the street frontage of a lot is 80 feet or less, all units on the lot shall share the same drive approach and driveway.
(d) 
Frontage Improvements. All required frontage improvements shall be completed prior to, or concurrently with, the building permit for an urban dwelling unit
(e) 
Denial Based Upon Adverse Impacts. The City will deny a proposed urban dwelling unit if the Building Official makes a written finding, based upon a preponderance of the evidence, that the proposed housing development project would have a specific, adverse impact, as defined and determined in paragraph (2) of subdivision (d) of Government Code Section 65589.5, upon public health and safety or the physical environment and for which there is no feasible method to satisfactorily mitigate or avoid the specific, adverse impact.
(f) 
Election of Development Standards. If necessary, objective zoning, subdivision, or design standards will be set aside for the construction of new units in the following order until the site can contain two 1,000 square foot units:
(1) 
Lot coverage;
(2) 
Second floor area limitations;
(3) 
Storage and laundry;
(4) 
Architectural features;
(5) 
Private open space;
(6) 
Setbacks to the degree allowed by State law;
(7) 
Shared driveway requirements.
(Ord. 657 § 2, 2022)
Urban dwelling units shall be subject to single-family impact fees, and all other development and utility connection fees, adopted and in effect at the time of permit application.
(Ord. 657 § 2, 2022)