Contra Costa County Municipal Code Ch. 88-36 Two-Unit Residential Developments in Single-Family Residential Zones

The purposes of this chapter are to authorize and regulate the development of up to two residential units on a qualifying lot located in a single-family residential zones; to establish a procedure for reviewing and approving the developments to ensure and maintain healthy and safe residential living environments; to establish location and development standards for the developments; and to comply with Government Code Sections 65852.21 and 66411.7, which require local agencies to consider applications for two-unit residential developments ministerially without discretionary review or public hearing.

(Ord. No. 2022-14, § II, 3-29-22)

For purposes of this chapter, the following words and phrases have the following meanings:

(a) "Accessory dwelling unit" has the meaning set forth in Government Code Section 65852.2.

(b) "Junior accessory dwelling unit" has the meaning set forth in Government Code Section 65852.22.

(c) "Residential unit" means a single-family dwelling, but does not include an accessory dwelling unit or junior accessory dwelling unit.

(d) "Urban housing development" means any of the following:

(1) A housing development containing no more than two residential units on a lot within a single-family residential zoning district or within a planned unit (P-1) district for single-family residential units that meets all of the requirements set forth in Government Code Section 65852.21.

(2) Any development on a lot created by an urban lot split.

(e) "Urban lot split" means a subdivision of an existing lot within a single-family residential zoning district into no more than two new parcels that meet all of the requirements set forth in Government Code Section 66411.7 and Article 94-4.410 of this code.

(Ord. No. 2022-14, § II, 3-29-22)

(a) Except as otherwise provided in this section, an application for a permit to establish an urban housing development will be approved ministerially without discretionary review or public hearing if the development meets: the location requirements specified in Section 88-36.010; the development standards specified in Section 88-36.012; all applicable building standards in Title 7; and all applicable sewage and water requirements.

(b) Notwithstanding subsection (a), the Department of Conservation and Development may deny an application for a permit to establish an urban housing development if the building official makes a written finding, based upon a preponderance of the evidence, that the proposed development would have a specific, adverse impact, as defined and determined in Government Code Section 65589.5(d)(2), 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.

(Ord. No. 2022-14, § II, 3-29-22)

(a) An application for an urban housing development permit must be submitted to the Department of Conservation and Development before a building permit application is submitted to the county.

(b) An application for an urban housing development permit must be made in writing and contain the following information:

(1) Name(s) and address(es) of applicant(s) and property owner(s).

(2) Address and assessor's parcel number for the lot.

(3) Whether the lot was created by an urban lot split.

(4) Size, indicating dimensions and square footage, of the existing and proposed dwelling units.

(5) A legible scale drawing, showing:

(A) A north arrow to indicate lot orientation.

(B) Lot dimensions and labels for all property lines.

(C) Siting and location of the existing and proposed dwelling units.

(D) Floor plan configuration of the existing and proposed dwelling units.

(E) All other existing improvements, including driveways and parking areas.

(F) Exterior design of the existing and proposed residential units. "Exterior design" includes exterior features, such as entrances, windows, and roof.

(6) Color photographs of the existing dwelling units and surrounding properties taken from each of the property lines of the project site.

(7) Location and description of water and sanitary services for the existing and proposed dwelling units.

(8) A preliminary drainage plan.

(9) Property owner's consent to physical inspection of the premises.

(10) A written legal description of the property.

(Ord. No. 2022-14, § II, 3-29-22)

An urban housing development may be established on any lot that meets all of the following requirements:

(a) The lot is located in a single-family residential zoning district (R-6, R-7, R-10, R-12, R-15, R-20, R-40, R-65, and R-100) or in a planned unit (P-1) district for single-family residential uses.

(b) The lot is located within the boundaries of an urbanized area or urban cluster, as designated by the United States Census Bureau.

(c) The lot meets the requirements of Government Codes Section 65913.4(a)(6)(B)-(K).

(d) The lot is not located within a historic district or property included on the State Historic Resources Inventory, as defined by Public Resources Code Section 5020.1, or in the County Historic Resources Inventory, as designated by the Board of Supervisors.

(Ord. No. 2022-14, § II, 3-29-22)

(a) Uses Allowed. Only residential uses and structures ancillary to residential uses are allowed in an urban housing development.

(b) Residential Units. An urban housing development may not include more than two residential units.

(c) Lot Size. The minimum size of a lot with an urban housing development is the 1,200 square feet. Section 82-10.002(c) does not apply to an application for an urban housing development permit.

(d) Lot Coverage.

(1) Except as otherwise provided in this subsection (d), the structures included in an urban housing development may not cover more than:

(A) 67 percent of the lot area on a lot of less than 3,000 square feet.

(B) 50 percent of the lot area on a lot of 3,000 square feet or more but less than 6,000 square feet.

(C) 40 percent of the lot area on a lot of 6,000 square feet or more but less than 12,000 square feet.

(D) 30 percent of the lot area on a lot of 12,000 square feet or more.

(2) The lot coverage limitations of this subsection may be exceeded to allow construction of one new residential unit on a lot with an existing residential unit, if the new residential unit does not exceed:

(A) 800 square feet in size on a lot of less than 6,000 square feet.

(B) 1,000 square feet in size on a lot of 6,000 square feet or more but less than 12,000 square feet.

(C) 1,200 square feet in size on a lot of 12,000 square feet or more.

(e) Yards and Building Height.

(1) Residential units included in an urban housing development must comply with all requirements relating to yards (front setbacks, side, and rear) and building height that are generally applicable to residential construction in the zone in which the lot is located, except as otherwise provided in this subsection (e).

(2) A setback is not required for an existing residential unit or a residential unit constructed in the same location and to the same dimensions as an existing building.

(3) A setback of four feet from the side and rear lot lines is required for a residential unit that is not an existing residential unit or is not constructed in the same location and to the same dimensions as an existing building.

(4) A residential unit or any portion of a residential unit that is located within a front, back, or side yard area applicable to residential construction in the zone in which the lot is located may not exceed 16 feet in height.

(f) Off-Street Parking.

(1) A lot containing an urban housing development must provide at least one off-street parking space per residential unit, except as otherwise provided in this subsection (f).

(2) No off-street parking is required for an urban housing development in any of the following instances:

(A) The urban housing development is located within one-half mile walking distance of a major transit stop, as defined in Public Resources Code Section 21064.3.

(B) The urban housing development is located within one-half mile walking distance of a high-quality transit corridor, as defined in Public Resources Code Section 21155(b).

(C) A car share vehicle pick-up location is within one block of the urban housing development. A "car share vehicle" has the same meaning as in Vehicle Code Section 22507.1.

(g) Accessory Dwelling Units.

(1) An urban housing development may include an accessory dwelling unit or junior accessory dwelling unit in accordance with Chapter 82-24.

(2) Notwithstanding subsection (1), an urban housing development that includes two residential units on a lot created by an urban lot split may not include an accessory dwelling unit or junior accessory dwelling unit.

(h) Modifications to Certain Housing Prohibited. An urban housing development may not require demolition or alteration of any of the following types of housing:

(1) A residential unit that is a deed-restricted below-market-rate residential unit.

(2) A residential unit that is subject to any form of rent or price control.

(3) A residential unit that has been occupied by a tenant in the last three years.

(i) Drainage. A lot containing an urban housing development must collect and convey all stormwater entering or originating on the lot, without diversion and within an adequate storm drainage system, to an adequate natural watercourse having definable bed and banks, or to an existing adequate public storm drainage system which conveys the stormwater to an adequate natural watercourse, in accordance with Division 914 of the Ordinance Code. All storm drainage facilities must be designed and constructed in compliance with this code and Public Works Department design standards.

(j) Stormwater Management. An urban housing development must comply with all applicable rules, regulations, and standards of the County's National Pollutant Discharge Elimination System (NPDES) permit as required by Division 1014.

(Ord. No. 2022-14, § II, 3-29-22)

No residential unit that is part of an urban housing development may be rented or offered for rent for a term of less than 30 days.

(Ord. No. 2022-14, § II, 3-29-22)

The fees for an urban housing development permit will be in amounts established by the Board of Supervisors in the Department of Conservation and Development's fee schedule. Urban housing developments are subject to all applicable fees for new development.

(Ord. No. 2022-14, § II, 3-29-22)