Chapter 88-36 — TWO-UNIT RESIDENTIAL DEVELOPMENTS IN SINGLE-FAMILY RESIDENTIAL ZONES
Contra Costa County Zoning Code · 2026-06 edition · ingested 2026-07-06 · Contra Costa County
88-36.002 - Purposes. ¶
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)
88-36.004 - Definitions. ¶
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)
88-36.006 - Permitting procedure. ¶
(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)
88-36.008 - Applications.
(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)
88-36.010 - Location. ¶
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)
88-36.012 - Development standards. ¶
(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)
88-36.014 - Occupancy. ¶
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)
88-36.016 - Fees. ¶
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)
Division 810 - AGRICULTURAL LAND CONSERVATION
Chapter 810-2 - AGRICULTURAL PRESERVES
Article 810-2.2. Establishment
810-2.202 - Establishment—By board of supervisors. ¶
The board of supervisors may by resolution designate suitable areas of the county as agricultural preserves pursuant to the California Land Conservation Act (Government Code Section 51200, ff. as amended) to be devoted to agricultural and compatible uses.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
Article 810-2.4. - Standards
810-2.402 - Standards—Compliance required. ¶
Agricultural preserves shall comply with the following uniform standards as set forth in Sections 810-2.404 through 810-2.414.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-2.404 - Standards—Minimum acreage. ¶
Except as provided in subdivisions (a) and (b), no agricultural preserve shall be established having less than one hundred contiguous acres.
(a)
Agricultural preserves of less than one hundred contiguous acres may be established if the Board finds that an agricultural preserve of less than one hundred acres is necessary due to the unique characteristics of the agricultural enterprise in that area and that the establishment of preserves of less than one hundred acres is consistent with the General Plan.
(b)
Agricultural Preserves of thirty-five contiguous acres may be established in the areas of the East Contra Costa and Byron-Bethany Irrigation Districts, as previously established by the Board of Supervisors
(Gov. Code, § 51230, Ords 2003-12 § 4, 72-58 § 1, 69-76 § 1 (part), 69-49 § 1 (part), 68-53.)
810-2.406 - Standards—Minimum parcel. ¶
No parcel of land of less than forty acres of non-prime agricultural land, or less than ten acres of prime agricultural land, shall be included in an agricultural preserve.
(Gov. Code, § 51222; Ords. 2003-12 § 5, 69-76 § 1 (part) 69-49 § 1 (part)).
810-2.407 - Standards—Prime agricultural land defined. ¶
As used in this title, prime agricultural land means any of the following:
(a)
all land that qualifies for rating as class I or II in the Natural Resource Conservation Service land use capability classifications;
(b)
all land that qualifies for rating eighty through one hundred in the Stone Index Rating;
(c)
land which supports livestock used for the production of food and fiber and which has an annual carrying capacity equivalent to at least one animal unit per acre as defined by the United States Department of Agriculture;
(d)
land planted with fruit- or nut-bearing trees, vines, bushes, or crops which have a nonbearing period of less than five years and which will normally return during the commercial bearing period on an annual basis from the production of unprocessed agricultural production not less than two hundred dollars per acre; and,
(e)
land which has returned from the production of unprocessed agricultural plant products an annual gross of not less than two hundred dollars ($200) per acre for three of the previous five years.
(Gov. Code, § 51201(c); Ords. 2003-12 § 6).
810-2.408 - Standards—Parcel defined. ¶
"Parcel" as used in this title means a contiguous area of land under common fee ownership.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-2.410 - Standards—Land subject to agreement. ¶
All land in a preserve must also be subject to a land conservation contract or agreement.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-2.412 - Standards—Land within one mile of city. ¶
Land within one mile of any city may be included in an agricultural preserve and placed under contract, but not if the city files with the local agency formation commission a resolution of protest which the commission upholds in the manner provided by Government Code Section 51243.5.
(Ord. 73-93 § 1, 1973: Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-2.414 - Standards—Land use restriction. ¶
Agricultural preserves shall include only land primarily used for commercial agricultural production.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
Chapter 810-4 - LAND CONSERVATION CONTRACTS
Article 810-4.2. - Establishment
810-4.202 - Establishment—Generally. ¶
Upon authorization by board resolution, its chairman may execute for the county, land conservation contracts with the owners of land located within agricultural preserves, pursuant to the California Land Conservation Act.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.204 - Establishment—Standard form. ¶
The board, by resolution, shall promulgate a standard form of land conservation contract, which may include provisions additional to, but not conflicting with those in this chapter.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
Article 810-4.4. Standards
810-4.402 - Standards—Compliance required. ¶
Land conservation contracts shall comply with the following uniform standards as set forth in Sections 8104.404 through 810-4.412.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.404 - Standards—Term. ¶
Contracts shall be for a term of ten years renewable annually in the manner provided in Government Code Section 51244.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.406 - Standards—Land use restriction. ¶
Contracts shall include landowner promises to restrict the use of the land to those commercial agricultural and compatible uses allowable in an agricultural preserve district (as set forth in Chapter 84-42).
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.408 - Standards—Noncompliance. ¶
Contracts shall provide that, if the landowner fails to comply with the agreement's terms and conditions so as to render the land or a portion thereof unfit for further agricultural use, the owner shall pay, as liquidated damages to the county, a sum equal to the equalized assessed value of the property as established by the county assessor on the lien date next following the date of breach. This provision shall not be deemed a waiver of other legal or equitable remedies for enforcement of the terms of the contract.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.410 - Standards—Cancellation. ¶
Contracts shall provide that they may be cancelled only by mutual agreement of the owner and county pursuant to the provisions of Government Code Sections 51282, 51283(a) and (b), and 51283.3, provided, however, that under no circumstances shall the payment of a cancellation fee provided for therein be waived, deferred, or made subject to any contingency whatever.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
810-4.412 - Standards—Division of property into two or more parcels. ¶
Contracts shall provide that division of property subject to agreement into two or more parcels may be construed by the county as a notice of nonrenewal by the property owner upon a finding by the board of supervisors that the effect of the division is detrimental to the ultimate preservation of the property for exclusive agricultural use.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
Article 810-4.6. Applications
810-4.602 - Application—Submission regulations. ¶
The board, by resolution, shall promulgate rules and procedures for submitting applications for land conservation contracts and for review of the applications by appropriate county agencies.
(Ord. 69-76 § 1 (part), 1969: Ord. 69-49 § 1 (part), 1969).
Division 812 - SCHOOL FACILITY DEDICATIONS Chapter 812-2 - GENERAL PROVISIONS
812-2.202 - Title and purpose. ¶
This division shall be known as the "School Facilities Dedication Ordinance of Contra Costa County." The purpose of this division is to provide a method for financing interim school facilities necessitated by new residential developments causing conditions of overcrowding.
(Ord. 78-10).
812-2.204 - Authority and conflict. ¶
This division is enacted pursuant to Chapter 4.7 (Government Code §§ 65970 ff) and constitutes the ordinance referred to in Sections 65972 and 65974 of Chapter 4.7. In the case of any conflict between the provisions of this division and those of Chapter 4.7, the latter shall prevail.
(Ord. 78-10).
812-2.206 - General plan. ¶
The county's general plan provides for the location of public schools. Interim school facilities to be constructed from fees or land required to be dedicated, or both, shall be consistent with the general plan.
(Ord. 78-10).
812-2.208 - Regulations. ¶
The board may from time to time, by resolution, issue regulations to establish administration, procedures, interpretation and policy direction for this division.
(Ord. 78-10).
Chapter 812-4 - DEFINITIONS
812-4.202 - Generally. ¶
Unless otherwise specifically provided, or required by the context, the following terms have the meanings set forth in this chapter for the purposes of this division.
(Ord. 78-10).
812-4.204 - Chapter 4.7.
"Chapter 4.7" means Chapter 4.7 (commencing with Section 65970) of Division 1 of Title 7 of the Government Code as added by Chapter 955 of the Statutes of 1977 and any subsequent amendments thereto.
(Ord. 78-10).
812-4.206 - Conditions of overcrowding. ¶
"Conditions of overcrowding" means that the total enrollment of a school, including enrollment from proposed development, exceeds the capacity of such school as determined by the governing body of the district.
(Ord. 78-10).
812-4.208 - Dwelling unit.
"Dwelling unit" means a building or a portion thereof, or a mobile home, designed for residential occupancy by one person or a group of two or more persons living together as a domestic unit.
(Ord. 78-10).
812-4.210 - Reasonable methods for mitigating conditions of overcrowding.
"Reasonable methods for mitigating conditions of overcrowding" includes, but is not limited to, agreements between a subdivider and the affected school district whereby temporary-use buildings will be leased to the school district or temporary-use buildings owned by the school district will be used.
(Ord. 78-10).
812-4.212 - Other methods for mitigating conditions of overcrowding. ¶
"Other methods for mitigating conditions of overcrowding" may include, but is not limited to the following:
(1)
The use of available annual revenue limit and bond revenues;
(2)
The use of funds which could be available from the sale of surplus school district real property and funds available from any other sources.
(Ord. 78-10).
812-4.214 - Residential development. ¶
"Residential development" means a project containing residential dwellings, including mobile homes, of one or more units or a subdivision of land for the purpose of constructing one or more residential dwelling units. "Residential development" includes, but is not limited to, a preliminary or final development plan, a subdivision tentative or final map, a parcel map, conditional use permit, a building permit, and any other discretionary permit for new residential use.
(Ord. 78-10).
Chapter 812-6 - OVERCROWDED ATTENDANCE AREAS
812-6.202 - Findings and notice. ¶
Pursuant to Chapter 4.7, the governing body of a school district may make findings supported by clear and convincing evidence that:
(1)
Conditions of overcrowding exist in one or more attendance areas within the district which will impair the normal functioning of educational programs including the reason for such conditions existing;
(2)
All reasonable methods of mitigating conditions of overcrowding have been evaluated; and
(3)
No feasible method for reducing such conditions exist. Upon making these findings the school district must provide the county with notice of its findings.
(Ord. 78-10).
812-6.204 - Notice of findings requirements. ¶
Any notice of findings sent by a school district to the county shall specify:
(1)
The findings listed in Section 812-6.202;
(2)
The mitigation measures and methods, including those listed in Sections 812-4.210 and 812-4.212, considered by the school district and any determination made concerning them by the district;
(3)
A description of the geographic boundaries of the overcrowded attendance area or areas;
(4)
Estimated annual school district costs to provide interim school facilities in the overcrowded attendance area or areas; and
(5)
Such other information as may be required by board regulation.
(Ords. 79-68 § 1, 78-10).
812-6.206 - County concurrence. ¶
After the receipt of any notice of findings complying with the requirement of Section 812-6.204, the board shall determine whether it concurs in such school district findings. The board shall schedule and hold a public hearing on the matter of its proposed concurrence prior to making its determination by resolution.
(Ord. 78-10).
812-6.208 - Findings for development approval. ¶
Within an attendance area where the board has concurred in a school district's notice of findings that conditions of overcrowding exist, the county's planning agency shall not approve an ordinance rezoning property to a residential use, grant a discretionary permit for residential use, or approve a tentative subdivision map for residential purposes, within such area, unless the planning agency makes one of the following findings:
(1)
That this division is an ordinance adopted pursuant to Section 65974 of Chapter 4.7;
(2)
That there are specific overriding fiscal, economic, social, or environmental factors which in the judgment of the planning agency would benefit the county, thereby justifying the approval of a residential development otherwise subject to the interim school facilities dedication provisions of this division.
(Ord. 78-10).
812-6.210 - School district schedule. ¶
Following the concurrence and decision by the county to require the dedication of land or the payment of fees, or both, for an attendance area, the governing body of the involved school district shall submit a schedule specifying how it will use the land or fees, or both, to solve the conditions of overcrowding. The schedule shall include the school sites to be used, the classroom facilities to be made available, and the times when such facilities will be available. In the event the governing body of the school district cannot meet the schedule, it shall submit modifications to the board of supervisors and the reasons for the modification.