Contra Costa County Municipal Code Ch. 74-4 Modifications

Footnotes:

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Editor's note— Ord. No. 2016-22, § III, adopted November 15, 2016, amended Ch. 74-4, in its entirety. At the editor's discretion those provisions have been treated as repealing Ch. 74-4, §§ 74-4.002—74-4.006; and enacting a new Ch. 74-4 to read as set out herein. Former ch. 74-4 pertained to similar subject matter, and was derived from Ord. No. 2015-22, § II, adopted December 8, 2015; Ord. No. 2013-24, § III, adopted December 3, 13; Ord. No. 2011-03, § III, adopted February 15, 2011; Ord. No. 2007-54 § 4; Ord. No. 2002-31 § 3; Ord. No. 99-17 § 6; Ord. No. 99-1; Ord. No. 90-100 § 6; Ord. No. 87-55 § 5; Ord. No. 80-14 § 6 and Ord. No. 74-30 § 1.

The 2025 California Building Code ("CBC") is amended by the changes, additions, and deletions set forth in this chapter and Division 72. Section numbers used in this section are those of the 2025 California Building Code.

(a) CBC Chapter 1 (Administration) is amended by the provisions of Division 72 of this code and as follows:

(1) Sections 103 and 113 of CBC Chapter 1 are deleted.

(2) In Section 105.2 (Work exempt from permit) of CBC Chapter 1 (Administration), subsection 4, is amended to read:

4. Retaining walls that are not more than 3 feet in height measured from the top of the footing to the top of the wall and that have a downward ground slope at the bottom of the retaining wall not exceeding 1 (vertical): 10 (horizontal), unless supporting a surcharge or ground slope exceeding 1 (vertical): 2 (horizontal) or impounding Class I, II, or III-a liquids.

(3) Section 107.2.1 (Information on Construction Documents) of CBC Chapter 1 (Administration) is amended to read:

107.2.1 Information on Construction Documents. Construction documents shall include dimensions and shall be drawn to scale on suitable material. Electronic media documents may be submitted when approved in advance by the building official. Construction documents shall be of sufficient clarity to indicate the location, nature, and extent of the work proposed and to show in detail that it will conform to this code and all relevant laws, ordinances, rules, and regulations. The first sheet of each set of plans shall include contact information for the owner and the person or persons who prepared the plans. Plans shall include a plot plan showing all existing property lines labeled and fully dimensioned, the elevations of the top and toe of cuts and fills, and the location of the proposed building with distances to all property lines and to every existing building on the property. Instead of detailed specifications, the county building official may approve references on the plans to a specific section or part of this code or other ordinances or laws.

(4) Section 110.1 (Inspections - General) of CBC Chapter 1 (Administration) is amended by adding the following to the end of that section:

At the time of first inspection by the county building official, a California licensed Land Surveyor or Civil Engineer shall certify in writing that the structure is placed according to the approved set of plans. The written certification must include the site address and permit number. This requirement does not apply to alterations or repairs to existing structures that do not affect the exterior limits of the existing structures.

(b) Section 907.2.11.2.5.1 is added to Section 907.2.11.2.5 (Existing Group R occupancies) of CBC Chapter 9 (Fire Protection and Life Safety Systems), to read:

907.2.11.2.5.1 Existing flat roof buildings. In existing flat roof buildings, the installation of a smoke detector that complies with California Residential Code Section R310.6 shall be required when a pitched roof is added on top of the existing flat roof and the solid sheathing of the flat roof is not removed.

(c) Section 1405.2 is added to Section 1405 (Combustible materials on the exterior side of exterior walls) of CBC Chapter 14 (Exterior Walls), to read:

1405.2 Wood shakes or shingles. Wood shakes or shingles used for exterior wall covering shall be fire treated.

(d) In Section 1705.3 (Concrete construction) of CBC Chapter 17 (Special Inspections and Tests), Exception 1 is amended to read:

1. Isolated spread concrete footings of buildings three stories or less above grade plane that are fully supported on earth or rock, where the structural design of the footing is based on a specified compressive strength of no greater than 2,500 pounds-per-square inch (psi) (17.2 MPa).

(e) Section 1809.8 (Plain concrete footings) of CBC Chapter 18 (Soils and Foundations) is deleted.

(f) Section 1810.3.9.3 (Placement of reinforcement) of CBC Chapter 18 (Soils and Foundations) is amended by deleting Exception 3.

(g) Section 1905.6.2 (Seismic design categories C, D, E, and F) of CBC Chapter 19 (Concrete) is amended to read:

1905.6.2 Seismic design categories C, D, E, and F. Structures assigned to Seismic Design Category C, D, E, or F shall not have elements of structural plain concrete, except as follows:

1. Reserved.

2. Isolated footings of plain concrete supporting pedestals or columns are permitted, provided the projection of the footing beyond the face of the supported member does not exceed the footing thickness.

3. Reserved.

(h) Section 1906 (Footings for light-frame construction) of CBC Chapter 19 (Concrete) is deleted.

(i) Section 1907.5 (Minimum Slab Provisions - General) is added to Section 1907 (Slabs- On-Ground) of CBC Chapter 19 (Concrete), to read:

Section 1907.5 Minimum Slab Provisions - General.

Slabs shall have a minimum reinforcement of 6-inch by 6-inch, 10-gauge wire mesh or equal at midheight of the slab.

(j) Appendix C, Appendix I, and Appendix P of the CBC are incorporated into the County building code.

(Ords. 2019-31 § III, 2016-22 § III)

(Ord. No. 2025-19, § III, 11-4-25; Ord. No. 2022-35, § III, 10-25-22)

The 2025 California Residential Code ("CRC") is amended by the changes, additions, and deletions set forth in this chapter and Division 72. Section numbers used in this section are those of the 2025 California Residential Code.

(a) CRC Chapter 1 (Administration) is amended by the provisions of Division 72 of this code and as follows:

(1) Sections RI 03 and RI 12 of CRC Chapter 1 are deleted.

(2) In Section RI05.2 (Work exempt from permit) of CRC Chapter 1 (Administration), subsection 3 is amended to read:

3. Retaining walls that are not more than 3 feet in height measured from the top of the footing to the top of the wall and that have a downward ground slope at the bottom of the retaining wall not exceeding 1 (vertical):10(horizontal), unless supporting a surcharge or ground slope exceeding l(vertical):2(horizontal) or impounding Class I, II, or Ill-a liquids.

(3) Section RI06.1.1 (Information on Construction Documents) of CRC Chapter 1 (Administration) is amended to read:

106.1.1 Information on Construction Documents. Construction documents shall include dimensions and shall be drawn to scale on suitable material. Electronic media documents may be submitted when approved in advance by the building official. Construction documents shall be of sufficient clarity to indicate the location, nature, and extent of the work proposed and to show in detail that it will conform to this code and all relevant laws, ordinances, rules, and regulations. The first sheet of each set of plans shall include contact information for the owner and the person or persons who prepared the plans. Plans shall include a plot plan showing all existing property lines labeled and fully dimensioned, the elevations of the top and toe of cuts and fills, and the location of the proposed building with distances to all property lines and to every existing building on the property. Instead of detailed specifications, the county building official may approve references on the plans to a specific section or part of this code or other ordinances or laws.

(4) Section RI09.1.1 (Foundation inspection) of CRC Chapter 1 (Administration) is amended by adding the following to the end of that section:

At the time of first inspection by the county building official, a California licensed Land Surveyor or Civil Engineer shall certify in writing that the structure is placed according to the approved set of plans. The written certification must include the site address and permit number. This requirement does not apply to alterations or repairs to existing structures that do not affect the exterior limits of the existing structures.

(b) Section R310.8.1.1 is added to Section R310.8 (Existing Group R-3 occupancies) of CRC Chapter 3 (Building Planning), to read:

R310.8.1.1 Existing flat roof buildings. In existing flat roof buildings, the installation of a smoke detector that complies with Section R310.6 shall be required when a pitched roof is added on top of the existing flat roof and the solid sheathing of the flat roof is not removed.

(c) Section R602.10.3(3) (Bracing Requirements Based on Seismic Design Category) of CRC Chapter 6 (Wall Construction) is amended as follows:

(1) The title of Table R602.10.3(3) is amended to read:

TABLE R602.10.3(3) i

(2) Footnote "i" is added to Table R602.10.3(3), to read:

i. Method GB is not permitted and the use of Method PCP is limited to one-story dwellings and accessory structures.

(d) Section R602.10.4.5 (Limits on methods GP and PCP) is added to Section R602.10.4 (Construction methods for braced wall panels) of CRC Chapter 6 (Wall Construction), to read:

R602.10.4.5 Limits on methods GB and PCP. Method GB is not permitted, but gypsum board is permitted to be installed on the opposite side of the studs from other types of braced wall panel sheathing. The use of Method PCP is limited to one-story dwellings and accessory structures.

(e) Appendix BB, Appendix BF, Appendix BJ, and Appendix CI of the CRC are incorporated into the County building code.

(Ords. 2019-31 § III, 2016-22 § III)

(Ord. No. 2025-19, § III, 11-4-25; Ord. No. 2022-35, § III, 10-25-22)

The 2025 California Green Building Standards Code ("CGBSC") is amended by the changes, additions, and deletions set forth in this chapter and Division 72. Section numbers used in this section are those of the 2025 California Green Building Standards Code.

(a) Section 301.1.1 (Additions and alterations) of CGBSC Chapter 3 (Green Building) is amended by adding the following to the end of that section:

The mandatory provisions of Section 4.408 shall apply to the following types of construction or demolition projects for existing residential buildings:

1. Projects that increase the total combined conditioned and unconditioned building area by 5,000 square feet or more.

2. Alterations to existing structures impacting 5,000 square feet or more of total combined conditioned and unconditioned building area.

3. Demolition projects when a demolition permit is required.

Exception: Demolition projects undertaken because the enforcing agency has determined that the demolition is necessary to abate a public nuisance or otherwise protect public health and safety.

For the purposes of determining whether a project meets the 5,000 square-foot threshold, the enforcing agency may deem all phases of a project and all related projects taking place on a single parcel, or on two or more adjoining parcel(s), as a single project.

(b) Section 301.3.2 (Waste diversion) of CGBSC Chapter 3 (Green Building) is amended to read:

Section 301.3.2 Waste diversion.

The requirements of Section 5.408 shall be required for additions, alterations, and demolition whenever a permit is required for work.

Exception: Demolition projects undertaken because the enforcing agency has determined that the demolition is necessary to abate a public nuisance or otherwise protect public health and safety.

(c) Section 4.106.4.2.2 (Multifamily Dwellings) of CGBSC Chapter 4 (Residential Mandatory Measures) is amended by adding subsection (2)(d) to the end of that section, to read:

d. EV Chargers. Notwithstanding anything in this section to the contrary, at least ten (10) percent of the total number of parking spaces shall be equipped with fully-operational Level 2 EVSE.

(d) Section 4.408.1 (Construction waste management) of CGBSC Chapter 4 (Residential Mandatory Measures) is amended to read:

Section 4.408.1 Construction waste management.

Recycle and/or salvage for reuse a minimum of 65 percent of the nonhazardous construction and demolition waste in accordance with Section 4.408.2.

Exceptions:

1. Excavated soil and land-clearing debris.

2. The enforcing agency may identify alternate waste reduction requirements if the agency determines that an owner or contractor has adequately demonstrated that diversion facilities necessary for the owner to comply with this section do not exist or are not located within a reasonable distance from the jobsite.

(e) Section 4.408.2 (Construction waste management plan) of CGBSC Chapter 4 (Residential Mandatory Measures) is amended to read:

Section 4.408.2 Construction waste management plan.

Submit a construction waste management plan for the project in conformance with Items 1 through 5 prior to issuance of a building permit. The construction waste management plan shall be updated as necessary, subject to approval by the enforcing agency. The approved plan, and any updates, shall be available during construction for examination by the enforcing agency. The plan must do all of the following:

1. Identify the construction and demolition waste materials to be diverted from disposal by recycling, reuse on the project, or salvage for future use or sale.

2. Specify if construction and demolition waste materials will be sorted on-site (source-separated) or bulk mixed (single stream).

3. Identify diversion and disposal facilities where the construction and demolition waste material will be taken and identify the waste management companies, if any, that will be utilized to haul the construction and demolition waste material. A waste management company utilized to haul construction and demolition waste material must have all applicable County approvals.

4. Identify construction methods employed to reduce the amount of construction and demolition waste generated.

5. Specify that the amount of construction and demolition debris shall be calculated consistent with the enforcing agency's requirements for the weighing of debris. The owner shall ensure that all construction and demolition debris diverted or disposed are measured and recorded by weight or volume using the most accurate method of measurement available. To the extent practicable, all construction and demolition debris shall be weighed using scales. Scales shall be in compliance with all regulatory requirements for accuracy and maintenance. For construction and demolition debris for which weighing is not possible due to lack of scales, or not practical due to materials being reused on-site or elsewhere, or not practical due to other considerations, and upon approval by the enforcing agency, a volumetric measurement shall be used. The owner shall convert volumetric measurements to weight using the standardized conversion factors approved by the enforcing agency for this purpose.

(f) Section 4.408.3 (Waste management company) of CGBSC Chapter 4 (Residential Mandatory Measures) is deleted.

(g) Section 4.408.5 (Documentation) of CGBSC Chapter 4 (Residential Mandatory Measures) is amended to read:

Section 4.408.5 Documentation.

A construction waste management final report containing information and supporting documentation that demonstrates compliance with Section 4.408.1, Section 4.408.2, Items 1 through 5, and, when applicable, Section 4.408.4 or Section 4.408.4.1, shall be provided to the enforcing agency before the final inspection. The required documentation shall include, but is not necessarily limited to, the following:

1. Documentation of the quantity, by weight, of each material type diverted or disposed, consistent with the requirements of Section 4.408.2, Item 5, and receipts or written certification from all receiving facilities utilized to divert or dispose of waste generated by the project that substantiate the amounts specified on the construction waste management final report; or

2. For projects that satisfy the waste stream reduction alternative specified in Section 4.408.4 or Section 4.408.4.1, documentation of the quantity, by weight, of each material type disposed of and the total combined weight of construction and demolition waste disposed in landfills as a result of the project, the corresponding pounds disposed per square foot of the building area, and receipts or written certification from all receiving facilities utilized to dispose waste generated by the project that substantiate the amounts specified on the construction waste management final report.

(h) Table 5.106.5.3.1 (EV Capable Spaces and EVCS) of CGBSC Chapter 5 (Nonresidential Mandatory Measures) is amended to read:

TABLE 5.106.5.3.1 - EV CAPABLE SPACES AND EVCS

1 Calculation for spaces shall be rounded up to the nearest whole number.

2 Each EVCS shall reduce the number of required EV capable spaces by the same number.

3 At least one Level 2 EVSE shall be provided.

(i) Section 5.408.1 (Construction waste management) of CGBSC Chapter 5 Nonresidential Mandatory Measures) is amended to read:

Section 5.408.1 Construction waste management.

Recycle and/or salvage for reuse a minimum of 65 percent of the nonhazardous construction and demolition waste in accordance with Section 5.408.1.1.

Exceptions:

1. Excavated soil and land-clearing debris.

2. The enforcing agency may identify alternate waste reduction requirements if the agency determines that an owner or contractor has adequately demonstrated that diversion facilities necessary for the owner to comply with this section do not exist.

(j) Section 5.408.1.1 (Construction waste management plan) of CGBSC Chapter 5 Nonresidential Mandatory Measures) is amended to read:

Section 5.408.1.1 Construction waste management plan.

Submit a construction waste management plan for the project in conformance with Items 1 through 5 prior to issuance of a building permit. The construction waste management plan shall be updated as necessary, subject to approval by the enforcing agency. The approved plan, and any updates, shall be available during construction for examination by the enforcing agency. The plan must do all of the following:

1. Identify the construction and demolition waste materials to be diverted from disposal by recycling, reuse on the project, or salvage for future use or sale.

2. Specify if construction and demolition waste materials will be sorted on-site (source-separated) or bulk mixed (single stream).

3. Identify diversion and disposal facilities where the construction and demolition waste material will be taken and identify the waste management companies, if any, that will be utilized to haul the construction and demolition waste material. A waste management company utilized to haul construction and demolition waste material must have all applicable County approvals.

4. Identify construction methods employed to reduce the amount of construction and demolition waste generated.

5. Specify that the amount of construction and demolition debris shall be calculated consistent with the enforcing agency's requirements for the weighing of debris. The owner shall ensure that all construction and demolition debris diverted or disposed are measured and recorded by weight or volume using the most accurate method of measurement available. To the extent practicable, all construction and demolition debris shall be weighed using scales. Scales shall be in compliance with all regulatory requirements for accuracy and maintenance. For construction and demolition debris for which weighing is not possible due to lack of scales, or not practical due to materials being reused on-site or elsewhere, or not practical due to other considerations, and upon approval by the enforcing agency, a volumetric measurement shall be used. The owner shall convert volumetric measurements to weight using the standardized conversion factors approved by the enforcing agency for this purpose.

(k) Section 5.408.1.2 (Waste management company) of CGBSC Chapter 5 (Nonresidential Mandatory Measures) is deleted.

(l) Section 5.408.1.4 (Documentation) of CGBSC Chapter 5 (Nonresidential Mandatory Measures) is amended to read:

Section 5.408.1.4 Documentation.

A construction waste management final report containing information and supporting documentation that demonstrates compliance with Section 5.408.1, Section 5.408.1.1, Items 1 through 5, and, when applicable, Section 5.408.1.3, shall be provided to the enforcing agency before the final inspection. The required documentation shall include, but may not necessarily be limited to, the following:

1. Documentation of the quantity, by weight, of each material type diverted or disposed, consistent with the requirements of Section 5.408.1.1, Item 5, and receipts or written certification from all receiving facilities utilized to divert or dispose of waste generated by the project that substantiate the amounts specified on the construction waste management final report; or

2. For projects that satisfy the waste stream reduction alternative specified in Section 5.408.1.3, documentation of the quantity, by weight, of each new construction material type disposed and the total combined weight of new construction waste disposed as a result of the project, the corresponding pounds of new construction disposal per square foot of the building area, and receipts or written certification from all receiving facilities utilized to dispose of waste generated by the project that substantiate the amounts specified on the construction waste management final report.

(Ords. 2019-31 § III, 2016-22 § III)

(Ord. No. 2025-19, § III, 11-4-25; Ord. No. 2022-35, § III, 10-25-22)

The 2025 California Existing Building Code ("CEBC") is amended by the changes, additions, and deletions set forth in this chapter and Division 72. Section numbers used in this section are those of the 2025 California Existing Building Code.

(a) CEBC Chapter 1 (Scope and Administration) is amended by the provisions of Division 72 of this code and as follows:

(1) Sections 103 and 112 of CEBC Chapter 1 (Scope and Administration) are deleted.

(2) Section 106.1 (Construction Documents - General) of CEBC Chapter 1 (Scope and Administration) is amended by deleting the exception.

(3) Section 106.2.1 (Construction documents) of CEBC Chapter 1 (Scope and Administration) is amended to read:

106.2.1 Construction documents. Construction documents shall include dimensions and shall be drawn to scale on suitable material. Electronic media documents may be submitted when approved in advance by the building official. Construction documents shall be of sufficient clarity to indicate the location, nature, and extent of the work proposed and to show in detail that it will conform to this code and all applicable laws, ordinances, rules, and regulations. The first sheet of each set of plans shall include contact information for the owner and for the person or persons who prepared the plans. Plans shall include a plot plan showing all existing property lines labeled and fully dimensioned, the elevations of the tops and toes of cuts and fills, and the location of the proposed building with distances to all property lines and to every existing building on the property. Instead of detailed specifications, the county building official may approve references on the plans to a specific section or part of this code or other ordinances or laws.

(Ords. 2019-31 § III, 2016-22 § III)

(Ord. No. 2025-19, § III, 11-4-25; Ord. No. 2022-35, § III, 10-25-22)

Editor's note— Ord. No. 2025-19, § III, adopted November 4, 2025, repealed § 74-4.010, which pertained to amendments to CEnC and derived from Ord. No. 2025-19, § III, 11-4-25; Ord. No. 2024-17, § II, 10-1-24; Ord. No. 2022-35, § IV, 10-25-22; Ord. No. 2022-02, § III, 1-18-22.