Chapter 3 — GENERAL REGULATIONS
301.5 Alternative Engineered Design.
California Plumbing Code (Title 24, Part 5) · 2025 edition · updated 2026-09-12 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
An alternative engineered design shall comply with the intent of the provisions of this code and shall provide an equivalent level of quality, strength, effectiveness, fire resistance, durability, and safety. Material, equipment, or components shall be designed and installed in accordance with the manufacturer’s installa tion instructions.
301.5.1 Permit Application. The registered design professional shall indicate on the design documents that the plumbing system, or parts thereof, is an alternative engineered design so that it is noted on the construction permit application. The permit and permanent permit records shall indicate that an alternative engineered design was part of the approved installation. 301.5.2 Technical Data. The registered design professional shall submit sufficient technical data to substantiate the proposed alternative engineered design and to prove that the performance meets the intent of this code. 301.5.3 Design Documents. The registered design professional shall provide two complete sets of signed and sealed design documents for the alternative engineered design for submittal to the Authority Having Jurisdiction. The design documents shall include floor plans and a riser diagram of the work. Where appropriate, the design documents shall indicate the direction of flow, pipe sizes, grade of horizontal piping, loading, and location of fixtures and appliances. 301.5.4 Design Approval. An approval of an alternative engineered design shall be at the discretion of the Authority Having Jurisdiction. The exercise of this discretionary approval by the Authority Having Jurisdiction shall have no effect beyond the jurisdictional boundaries of said Authority Having Jurisdiction. An alternative engineered design so approved shall not be considered as in accordance with the requirements, intent, or both of this code for a purpose other than that granted by the Authority Having Jurisdiction. 301.5.5 Design Review. The Authority Having Jurisdiction shall have the authority to require testing of the alternative engineered design in accordance with Section 301.3.1, including the authority to require an independ
ent review of the design documents by a registered design professional selected by the Authority Having Jurisdiction and at the expense of the applicant. 301.5.6 Inspection and Testing. The alternative engineered design shall be tested and inspected in accordance with the submitted testing and inspection plan and the requirements of this code.
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Ask AI about this code▸Contents — California Plumbing Code (Title 24, Part 5)
- Chapter 1 — GENERAL CODE PROVISIONS
- Chapter 2 — DEFINITIONS
▸Chapter 3 — GENERAL REGULATIONS
Overview- 301.1 Applicability.
- 301.2 Minimum Standards.
- 301.3 Alternate Materials and Methods of Construction Equivale…
- 301.4 Flood Hazard Areas.
- 301.5 Alternative Engineered Design.
- 301.6 Tall Wood (Mass Timber) Buildings.
- 301.7 One- and Two-Family Dwellings. [HCD 1]
- 301.8 OSHPD 1R. [OSHPD 1R]
- 302.1 General.
- 303.1 General.
- 304.1 General.
- 305.1 Unlawful Practices.
- 306.1 Detrimental Wastes.
- 306.2 Safe Discharge.
- 307.1 System.
- 307.2 Ownership.
- 308.1 General.
- 309.1 Engineering Practices.
- 309.2 Concealing Imperfections.
- 309.3 Burred Ends.
- 309.4 Installation Practices.
- 309.5 Sound Transmission.
- 309.6 Dead Legs.
- 310.1 Fittings.
- 310.2 Drainage and Vent Piping.
- 310.3 Waste Connection.
- 310.4 Use of Vent and Waste Pipes.
- 310.5 Obstruction of Flow.
- 310.6 Dissimilar Metals.
- 310.7 Direction of Flow.
- 310.8 Screwed Fittings.
- 310.9 Female Plastic Connections.
- 310.10 ABS and PVC Transition Joints.
- 310.11 [OSHPD 1, 2, 3, 4 & 5]
- 310.12 [OSHPD 1, 3, 4 & 5]
- 310.13 [SFM]
- 310.14 Services/Systems and Utilities. [OSHPD 1, 2, 4
- 310.15 Telephone and Data Equipment Rooms.
- 311.1 General.
- 312.1 General.
- 312.2 Installation.
- 312.3 Building Sewer and Drainage Piping.
- 312.4 Corrosion, Erosion, and Mechanical Damage.
- 312.5 Protectively Coated Pipe.
- 312.6 Freezing Protection.
- 312.7 Fire-Resistant Construction.
- 312.8 Waterproofing of Openings.
- 312.9 Steel Nail Plates.
- 312.10 Sleeves.
- 312.11 Structural Members.
- 312.12 Rodentproofing.
- 313.1 General.
- 313.2 Material.
- 313.3 Suspended Piping.
- 313.4 Alignment.
- 313.5 Underground Installation.
- 313.6 Hanger Rod Sizes.
- 313.7 Gas Piping.
- 313.8 [OSHPD 1, 2, 3, 4 & 5]
- 314.1 Trenches.
- 314.2 Tunneling and Driving.
- 314.3 Open Trenches.
- 314.4 Excavations.
- 315.1 Unions.
- 315.2 Prohibited Joints and Connections.
- 316.1 General.
- 317.1 General.
- 318.1 General.
- 318.2 Pressure Tests (10 psi or less).
- 318.3 Pressure Tests (greater than 10 psi to 100 psi).
- 318.4 Pressure Tests (exceeding 100 psi).
- 318.5 Pressure Range.
- 319.1 General.
- 320.1 General.
- 323.0 Plumbing Equipment Schedules. [OSHPD 1, 2,
- Chapter 4 — PLUMBING FIXTURES AND FIXTURE FITTINGS
- Chapter 5 — WATER HEATERS
- Chapter 6 — WATER SUPPLY AND DISTRIBUTION
- Chapter 7 — SANITARY DRAINAGE
- Chapter 8 — INDIRECT WASTES
- Chapter 9 — VENTS
- Chapter 10 — TRAPS AND INTERCEPTORS
- Chapter 11 — STORM DRAINAGE
- Chapter 12 — FUEL GAS PIPING
- Chapter 13 — HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICA…
- Chapter 14 — FIRESTOP PROTECTION
- Chapter 15 — ALTERNATE WATER SOURCES FOR NONPOTABLE APPLICATIONS
- Chapter 16 — NONPOTABLE RAINWATER CATCHMENT SYSTEMS
- Chapter 17 — REFERENCED STANDARDS
- Appendix A — RECOMMENDED RULES FOR SIZING THE WATER SUPPLY SYS…
- Appendix B — EXPLANATORY NOTES ON COMBINATION WASTE AND VENT S…
- Appendix C — ALTERNATE PLUMBING SYSTEMS
- Appendix D — SIZING STORM WATER DRAINAGE SYSTEMS
- Appendix E — MANUFACTURED/MOBILE HOME PARKS AND RECREATIONAL V…
- Appendix F — FIREFIGHTER BREATHING AIR REPLENISHMENT SYSTEMS
- Appendix G — SIZING OF VENTING SYSTEMS
- Appendix H — PRIVATE SEWAGE DISPOSAL SYSTEMS
- Appendix I — INSTALLATION STANDARDS
- Appendix J — COMBINATION OF INDOOR AND OUTDOOR COMBUSTION AND …
- Appendix K — POTABLE RAINWATER CATCHMENT SYSTEMS
- Appendix L — SUSTAINABLE PRACTICES
- Appendix M — PEAK WATER DEMAND CALCULATOR
- Appendix N — IMPACT OF WATER TEMPERATURE ON THE POTENTIAL FOR …
- Appendix O — NON-SEWERED SANITATION SYSTEMS
- Appendix P — PROFESSIONAL QUALIFICATIONS
- Appendix Q — INDOOR HORTICULTURAL FACILITIES
- Appendix R — TINY HOUSES
- Appendix S — ONSITE STORMWATER TREATMENT SYSTEMS