California MEP & Code: 63 Issues Found

Summary: The plumbing notes explicitly direct all work to conform to the 2018 International Plumbing Code (IPC) and the International Mechanical Code (IMC). However, the 2022 California Building Code explicitly states that plumbing and mechanical systems are governed by the California Plumbing Code (CPC) and the California Mechanical Code (CMC).

Why it matters: Applying the IPC and IMC instead of California's state-adopted codes (the CPC and CMC) is a critical compliance failure. The California codes (which are based on the Uniform Plumbing Code and Uniform Mechanical Code) have fundamentally different methodologies and requirements for pipe sizing, ven...

Suggested next step: Please revise General Notes 1 and 26 to reference the currently adopted California Plumbing Code (CPC) and California Mechanical Code (CMC) in lieu of the IPC and IMC. Please also confirm that all pipe sizing, venting schemes, and system details have been designed in complianc...

RFI draft: Please revise General Notes 1 and 26 to reference the currently adopted California Plumbing Code (CPC) and California Mechanical Code (CMC) in lieu of the IPC and IMC. Please also confirm that all pipe sizing, venting schemes, and system details h...

Summary: The general electrical notes explicitly specify that 'ALL NEUTRAL WIRES WILL BE BLACK IN COLOR' and 'UPS NEUTRAL WIRES WILL BE BLUE IN COLOR'. Section 2701.1 of the building code mandates that the California Electrical Code shall govern the design and installation of electrical components. Under California electrical standards, black and blue are designated for ungrounded (hot/phase) conductors...

Why it matters: Using black for neutral wires creates a severe life-safety hazard. Electricians and maintenance personnel in the US universally identify black wires as energized (hot). If installed as specified in these notes, workers could be exposed to electrocution risks, and the installation will fail electr...

Suggested next step: Please revise the electrical general notes to align with the California Electrical Code. Specifically, designate white or gray for neutral conductors and reserve black, red, or blue for ungrounded (phase) conductors.

RFI draft: Please revise the electrical general notes to align with the California Electrical Code. Specifically, designate white or gray for neutral conductors and reserve black, red, or blue for ungrounded (phase) conductors.

Summary: The Electrical Symbol Key on sheet E002 defines detection symbols but only includes "SD. SMOKE DETECTOR CEILING MOUNTED" — no carbon monoxide (CO) detector symbol is listed. The electrical plan shows smoke detector hexagon symbols (SD.) in select rooms but no CO detection devices anywhere on the plan. Since smoke detectors are explicitly shown on this electrical plan and defined in its legend, ...

Why it matters: This is a life-safety requirement. Failure to include CO detection would result in plan check rejection or inspection failure. The building includes an attached garage (a common CO source) and a "TANK LESS" appliance noted on the exterior. Retroactively adding CO detection after construction woul...

Suggested next step: Request the electrical engineer add carbon monoxide detection devices to the electrical plan and legend in accordance with Section 308.1 of the 2022 CEBC and the California Fire Code or CRC Section R315. Confirm device locations include all required areas per the applicable CO...

RFI draft: Request the electrical engineer add carbon monoxide detection devices to the electrical plan and legend in accordance with Section 308.1 of the 2022 CEBC and the California Fire Code or CRC Section R315. Confirm device locations include all requir...

Summary: Plumbing Note 1 explicitly states all work shall conform to the "2018 INTERNATIONAL PLUMBING CODE." Note 19 references support spacing "IN ACCORDANCE WITH INTERNATIONAL PLUMBING CODE" and Note 21 requires pressure testing "IN ACCORDANCE WITH THE IPC." However, Section 302.2 of the 2022 California Existing Building Code requires that alterations to existing buildings shall comply with the Califo...

Why it matters: Designing and constructing to IPC requirements in a California jurisdiction will almost certainly result in plan check rejection by the Authority Having Jurisdiction. Pipe sizing, trap and vent sizing, and fixture unit calculations differ between the two codes, meaning the entire water supply and...

Suggested next step: Request that the plumbing designer revise all plumbing notes (Notes 1, 19, 21, and any other references to the IPC) to reference the current California Plumbing Code (CPC) and confirm the entire plumbing design—including pipe sizing, venting, and testing requirements—complies ...

RFI draft: Request that the plumbing designer revise all plumbing notes (Notes 1, 19, 21, and any other references to the IPC) to reference the current California Plumbing Code (CPC) and confirm the entire plumbing design—including pipe sizing, venting, and ...

Summary: The plumbing notes on sheet P001 repeatedly direct compliance with the wrong code. Note 1 states all work shall conform to the "2018 INTERNATIONAL PLUMBING CODE." Note 19 directs support spacing "IN ACCORDANCE WITH INTERNATIONAL PLUMBING CODE." Note 21 directs pressure testing "IN ACCORDANCE WITH THE IPC." The applicable code for this California project is the 2022 California Plumbing Code (CPC...

Why it matters: Any California plan checker will reject drawings that reference the IPC instead of the CPC during plan review, causing immediate permit delay. If construction were to begin under IPC requirements before the discrepancy is caught, installations for pipe support spacing, pressure testing procedures...

Suggested next step: Request the plumbing designer revise all notes on sheet P001 to reference the 2022 California Plumbing Code instead of the 2018 International Plumbing Code. Specifically, revise Note 1 to cite the 2022 CPC as the governing code, revise Note 19 to reference CPC Table 313.3 for ...

RFI draft: Request the plumbing designer revise all notes on sheet P001 to reference the 2022 California Plumbing Code instead of the 2018 International Plumbing Code. Specifically, revise Note 1 to cite the 2022 CPC as the governing code, revise Note 19 to ...

Summary: The PLUMBING RAISER DETAIL explicitly labels "2"Ø WASTE PIPE WITH TUBULAR "S" TRAP" at both the lavatory/sink and tub/shower fixture connections. An S-trap has a vertical outlet leg below the trap weir that inherently creates self-siphoning conditions during fixture drainage. The vertical drop acts as a siphon tube that pulls the water seal out of the trap, leaving it empty and allowing sewer g...

Why it matters: S-traps will be rejected during plan review by the Authority Having Jurisdiction. If constructed as detailed, the trap seals will self-siphon during normal use, allowing sewer gases (including hydrogen sulfide and methane) to enter the habitable spaces. This is a health and safety issue requiring...

Suggested next step: RFI to the plumbing designer: The PLUMBING RAISER DETAIL shows tubular "S" traps at the lavatory/sink and tub/shower fixtures. S-traps cannot provide the siphonage protection required by CPC Section 901.2 and the trap seal protection required by Section 901.3. Please revise th...

RFI draft: RFI to the plumbing designer: The PLUMBING RAISER DETAIL shows tubular "S" traps at the lavatory/sink and tub/shower fixtures. S-traps cannot provide the siphonage protection required by CPC Section 901.2 and the trap seal protection required by S...

Summary: The water supply plan consistently labels hot water supply (HWS) fixture branch pipes as Ø1/4" at multiple locations including kitchen sink, laundry room, and both bathrooms. Table 610.3 of the 2022 California Plumbing Code requires a minimum fixture branch pipe size of 1/2 inch for bathtubs, lavatories, kitchen sinks, and laundry sinks. The labeled Ø1/4" hot water branches are half the code-re...

Why it matters: Undersized 1/4" hot water supply branches would be rejected at plan check by the Authority Having Jurisdiction and would fail rough-in inspection if installed. The pipes would deliver severely inadequate flow to fixtures, and correcting them post-installation would require re-piping of all hot wa...

Suggested next step: Request the plumbing designer confirm and correct the hot water supply (HWS) fixture branch pipe sizes shown on the Water Supply Plan. Per Table 610.3, the minimum fixture branch pipe size for bathtubs, lavatories, kitchen sinks, and laundry sinks is 1/2 inch. All branches cur...

RFI draft: Request the plumbing designer confirm and correct the hot water supply (HWS) fixture branch pipe sizes shown on the Water Supply Plan. Per Table 610.3, the minimum fixture branch pipe size for bathtubs, lavatories, kitchen sinks, and laundry sinks...

Summary: The sewerage line plan labels a Ø3" vent near the laundry/kitchen area as "Ø3"VENT TO ROOM" while the other vents on the same plan are correctly labeled "Ø2"VENT TO ROOF" (visible near the right-side bathroom serving Bedroom 01). Section 906.1 requires each vent pipe or stack to extend through its flashing and terminate vertically not less than 6 inches above the roof. A vent terminating inside...

Why it matters: If constructed as labeled, this vent would discharge sewer gases directly into the habitable space, creating a serious health and safety hazard. This will be flagged at plan review or inspection, causing a stop-work or correction order. The contractor would need to re-route the vent through the r...

Suggested next step: Request the plumbing designer clarify whether the label "Ø3" VENT TO ROOM" near the laundry/kitchen area on the sewerage line plan is a drafting error and should read "VENT TO ROOF" consistent with the other vents shown on the plan. Confirm the vent terminates through the roof...

RFI draft: Request the plumbing designer clarify whether the label "Ø3" VENT TO ROOM" near the laundry/kitchen area on the sewerage line plan is a drafting error and should read "VENT TO ROOF" consistent with the other vents shown on the plan. Confirm the ve...

Summary: Plumbing Note 6 permits the use of PEX tubing for piping 1" and smaller. However, Plumbing Note 22 mandates that all potable water piping be flushed strictly per 'AMERICAN WATER WORKS ASSOCIATION STANDARDS'. This conflicts with the California Plumbing Code, which requires a specific 1-week standing flush, application of warning tags, and a written certification to the building official prior to...

Why it matters: AWWA flushing standards do not satisfy California's strict PEX flushing and tagging protocols. The code explicitly states that the building official shall not give final permit approval unless the PEX installation complies with these specific CA flushing requirements. Specifying only AWWA standar...

Suggested next step: Please revise the plumbing notes to explicitly mandate the California-specific PEX flushing, tagging, and written certification requirements (including the 1-week standing flush) if PEX tubing is utilized, rather than solely referencing AWWA standards.

RFI draft: Please revise the plumbing notes to explicitly mandate the California-specific PEX flushing, tagging, and written certification requirements (including the 1-week standing flush) if PEX tubing is utilized, rather than solely referencing AWWA stand...

Summary: The floor plan shows Bedroom 02 as a room with no windows or exterior door openings depicted on any wall. While adjacent rooms clearly show window symbols — Bath and W.I.C. have window openings on the right (east) exterior wall, and Bedroom 01 has a window on its exterior wall — Bedroom 02 has none. Bedroom 02 is bounded by the Living Room and hallway to the north (interior walls with door), Ba...

Why it matters: This is a critical life safety deficiency. A sleeping room without an EERO provides no alternative means of escape if fire blocks the interior egress path. This will be flagged during plan review. Since Bedroom 02 does have an exterior wall on its west side, a code-compliant EERO opening (operabl...

Suggested next step: Clarify how Bedroom 02 will comply with Section R310.1 for emergency escape and rescue openings. The west wall of Bedroom 02 appears to be an exterior wall — confirm whether an operable window or door meeting EERO size requirements can be provided on this wall. Alternatively, ...

RFI draft: Clarify how Bedroom 02 will comply with Section R310.1 for emergency escape and rescue openings. The west wall of Bedroom 02 appears to be an exterior wall — confirm whether an operable window or door meeting EERO size requirements can be provided...

Summary: The electrical plan shows an attached garage as part of the dwelling and notes exterior equipment labeled "TANK LESS" (potentially a fuel-fired tankless water heater). However, the Electrical Symbol Key contains no carbon monoxide alarm symbol, and no CO alarm devices are depicted anywhere on the plan. Per R315.2.1, carbon monoxide alarms are required in dwelling units that contain a fuel-fired...

Why it matters: Failure to provide CO alarms where required is a life-safety violation that will be flagged during plan review and inspection, causing permit delays. CO alarm locations must be identified on the electrical plan to ensure proper installation during construction. This omission will require plan rev...

Suggested next step: Request the designer add carbon monoxide alarm locations to the electrical plan per R315.2.1, including a CO alarm symbol in the Electrical Symbol Key. Confirm whether the attached garage has an opening communicating with the dwelling unit and whether the tankless unit is fuel...

RFI draft: Request the designer add carbon monoxide alarm locations to the electrical plan per R315.2.1, including a CO alarm symbol in the Electrical Symbol Key. Confirm whether the attached garage has an opening communicating with the dwelling unit and whe...

Summary: The electrical plan includes a smoke detector symbol ("SD.") in the symbol key, but in the area labeled "BEDROOM 01" the plan description lists recessed lighting and indicates the "SD." devices are located "in/near the hall/door zone" rather than within the bedroom. CRC requires a smoke alarm in each sleeping room.

Why it matters: If Bedroom 01 is constructed/inspected without a smoke alarm located within the room, this is a life-safety code violation and will likely fail inspection, requiring added wiring/device installation and rework.

Suggested next step: Revise the electrical plan to show a code-compliant smoke alarm location within "BEDROOM 01" and confirm smoke alarm placement meets CRC R314.3, including coordination with the symbol key used on this sheet.

RFI draft: Revise the electrical plan to show a code-compliant smoke alarm location within "BEDROOM 01" and confirm smoke alarm placement meets CRC R314.3, including coordination with the symbol key used on this sheet.

Summary: The Main Floor Existing Electrical Plan documents smoke detector (SD) locations throughout the dwelling. The plan shows a ceiling-mounted smoke detector (SD) inside Bedroom 02, but no smoke detector symbol is shown inside Bedroom 01. The detailed view of Bedroom 01 shows four recessed lights, switches, and receptacles fully documented, yet no SD symbol is placed within the room. The two SD symb...

Why it matters: A missing smoke alarm in a sleeping room is a life-safety code violation that would result in inspection failure and a construction or occupancy delay. Per R310.2.2, where alterations, repairs, or additions requiring a permit occur, the individual dwelling unit shall be equipped with smoke alarms...

Suggested next step: Confirm whether a smoke alarm is intended to be installed inside Bedroom 01. If so, add an SD symbol inside Bedroom 01 on the proposed electrical plan and connect it to the smoke alarm circuit. Ensure the device is interconnected with the other smoke alarms in the dwelling uni...

RFI draft: Confirm whether a smoke alarm is intended to be installed inside Bedroom 01. If so, add an SD symbol inside Bedroom 01 on the proposed electrical plan and connect it to the smoke alarm circuit. Ensure the device is interconnected with the other sm...

Summary: The electrical plan shows a dwelling with an attached GARAGE as part of the main floor layout and exterior equipment labeled "TANK LESS" (commonly a gas tankless water heater, which would constitute a fuel-fired appliance). Per CRC R311.2.1, carbon monoxide alarms are required in dwelling units where the dwelling unit contains a fuel-fired appliance or has an attached garage with an opening tha...

Why it matters: Carbon monoxide alarms are a critical life-safety requirement under the California Residential Code. The complete absence of CO alarm symbols from the electrical legend and plan means these devices will not be roughed-in during electrical work, leading to plan check rejection or failed inspection...

Suggested next step: Request that the designer add a carbon monoxide alarm symbol to the Electrical Symbol Key and show CO alarm locations on the electrical plan in compliance with CRC R311.2.1, R311.3, and R311.6. At minimum, CO alarms are required outside each separate sleeping area in the immed...

RFI draft: Request that the designer add a carbon monoxide alarm symbol to the Electrical Symbol Key and show CO alarm locations on the electrical plan in compliance with CRC R311.2.1, R311.3, and R311.6. At minimum, CO alarms are required outside each separ...

Summary: The Mechanical Plan shows supply air diffusers (rectangle-with-X symbols) in multiple bathroom spaces (at least two rooms labeled "BATH") but does not show any exhaust fan or wall exhaust grill symbols in any bathroom. The drawing legend explicitly defines both "EXHAUST FAN" and "WALL EXHAUST GRILL" symbols for use on this sheet, yet neither symbol is placed in any bathroom on the plan. Section...

Why it matters: This omission will be identified during plan review and will result in permit rejection or a correction notice. Bathroom exhaust ventilation is a mandatory code requirement that cannot be waived. Failure to include exhaust fans and associated ductwork to the outdoors on the mechanical plan will d...

Suggested next step: Request the mechanical designer to add exhaust fans in all bathrooms with ductwork routed to the outdoors, sized per California Mechanical Code Chapter 4 (minimum 50 CFM intermittent or 20 CFM continuous), as required by Section R325.2.1. Revise the mechanical plan to show exh...

RFI draft: Request the mechanical designer to add exhaust fans in all bathrooms with ductwork routed to the outdoors, sized per California Mechanical Code Chapter 4 (minimum 50 CFM intermittent or 20 CFM continuous), as required by Section R325.2.1. Revise t...