Title 24 · California Energy Code

How large must raceways, transformers and panels be sized to accommodate future medium/heavy EVSE?

If you’re building for loading docks or planned off‑street loading, California requires you to install spare raceway(s)/busway(s) and reserve the transformer/panel capacity shown in Table 5.106.5.5.1 now so medium/heavy vehicle chargers can be connected later without tearing up the building.

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Last reviewed: July 6, 2026

What the code requires — plain English

The California Green Building Standards Code requires that new construction serving planned off‑street loading spaces install spare raceway(s) or busway(s) and provide adequate capacity for transformer(s), service panel(s) or subpanels at the time of construction so medium‑ and heavy‑duty EV supply equipment (EVSE) can be added later without demolition — see § 5.106.5.5.1.

Provide spare raceway(s)/busway(s) and add transformer/panel capacity now per Table 5.106.5.5.1 so medium/heavy EV chargers can be connected later without reworking the building service.

Requirements in detail

Summary of the four required items in § 5.106.5.5.1 (items 1–4)

  • Item 1: Transformer, main service equipment and subpanels must meet the minimum power requirement listed in Table 5.106.5.5.1.
  • Item 2: Construction documents must show one or more convenient location(s) for medium/heavy charging cabinets/dispensers and a reserved pathway from the raceway/busway termination to those locations.
  • Item 3: Raceway(s) or busway(s) must originate at the main service panel or a subpanel serving the area and terminate close to the future charging equipment location.
  • Item 4: The raceway(s) or busway(s) must be sized large enough to carry the minimum additional system load shown in Table 5.106.5.5.1 (the table sets the kVA the raceway/panel/transformer must be able to accommodate).

Key related minimum raceway guidance

  • For EV capable (light‑duty) parking spaces the Code requires raceways of no less than 1‑inch (25 mm) trade size originating at the service or subpanel; while § 5.106.5.5.1 does not restate that diameter, the general raceway sizing rule for EV work is in § 5.106.5.3.1.

Decision‑relevant table (minimum additional capacity to be provided for medium/heavy EVSE)

This table reproduces the decision values you must design for. The Code requires transformer/panel/raceway capacity per Table 5.106.5.5.1 in § 5.106.5.5.1.

Building Type Building Size (sq ft) # Off‑street loading spaces Additional capacity required for raceway/busway and transformer & panel (kVA) Code Reference
Grocery 10,000 – 90,000 1–2 200 kVA § 5.106.5.5.1
Grocery 10,000 – 90,000 3 or greater 400 kVA § 5.106.5.5.1
Grocery Greater than 90,000 1 or greater 400 kVA § 5.106.5.5.1
Manufacturing 10,000 – 50,000 1–2 200 kVA § 5.106.5.5.1
Manufacturing 10,000 – 50,000 3 or greater 400 kVA § 5.106.5.5.1
Manufacturing Greater than 50,000 1 or greater 400 kVA § 5.106.5.5.1
Office 10,000 – 135,000 1–2 200 kVA § 5.106.5.5.1
Office 10,000 – 135,000 3 or greater 400 kVA § 5.106.5.5.1
Office Greater than 135,000 1 or greater 400 kVA § 5.106.5.5.1
Retail 10,000 – 135,000 1–2 200 kVA § 5.106.5.5.1
Retail 10,000 – 135,000 3 or greater 400 kVA § 5.106.5.5.1
Retail Greater than 135,000 1 or greater 400 kVA § 5.106.5.5.1
Warehouse 20,000 – 256,000 1–2 200 kVA § 5.106.5.5.1
Warehouse 20,000 – 256,000 3 or greater 400 kVA § 5.106.5.5.1
Warehouse Greater than 256,000 1 or greater 400 kVA § 5.106.5.5.1

Notes on the table and how to use it

  • The Table sets the additional kVA that the raceway, busway and the transformer/panels must be capable of carrying or accommodating. The Code does not prescribe specific conduit diameters in Table 5.106.5.5.1 — it requires that the raceway/busway be sized to carry that load.
  • For minimum physical raceway size guidance for EV capable installations (light duty) see § 5.106.5.3.1 which requires raceway trade size no less than 1‑inch originating at the service or subpanel; § 5.106.5.5.1 refers you to the California Electrical Code for final conduit/conductor sizing.

Exceptions & special cases

  • The Code allows the local enforcing agency to grant exceptions where compliance is not feasible because: no local utility power supply; the utility cannot supply adequate power; or additional utility infrastructure requirements would unreasonably increase cost — see § 5.106.5.5 exceptions.
  • The section applies specifically to warehouses, grocery stores, office buildings, manufacturing facilities and retail stores with planned off‑street loading spaces. Projects not in those categories or without planned loading spaces are not subject to this subsection.
  • The Code requires coordination with the California Electrical Code and the local utility for final conductor sizes, conduit counts, transformer pad/enclosure sizes and utility service upgrades; those specifics live in the Electrical Code and utility standards rather than in § 5.106.5.5.1.

Common mistakes

  • Treating the table’s kVA as the rating of a single charger. The table sets spare system capacity to be reserved for future medium/heavy EVSE, not the rating of any one dispenser. § 5.106.5.5.1 specifies system capacity additions (kVA).
  • Installing raceways that are physically present but too small to pull the conductors needed to serve the kVA in the table. The Code requires raceways/busways to be sized to carry the minimum additional system load in the table — physical diameter matters.
  • Forgetting to show the reserved pathway and termination locations on construction documents. § 5.106.5.5.1 requires the construction documents to indicate location(s) and pathway(s).
  • Relying only on "EV capable" (light‑duty) 1‑inch raceway guidance without confirming medium/heavy equipment needs; medium/heavy EVSE may require larger conductors or three‑phase service and the Code requires sizing per Table 5.106.5.5.1 and the California Electrical Code.

Worked example — retail loading area

Scenario: New retail building — 120,000 sq ft with 4 off‑street loading spaces. Table 5.106.5.5.1 requires 400 kVA additional capacity for this configuration. § 5.106.5.5.1 and its Table require the transformer, service panel/subpanels and raceway/busway be sized to accommodate that 400 kVA.

Practical steps to document and design (illustrative calculations)

  1. Code requirement: Reserve 400 kVA additional capacity at the transformer/panel/raceway termination per § 5.106.5.5.1.
  2. Convert kVA to available current (to size conductors/panels) — assume a future 480 V, 3‑phase feeder (common for medium/heavy EVSE): I = kVA×1000 / (√3 × V). For 400 kVA: I ≈ 400,000 / (1.732 × 480) ≈ 481 A. (This is an engineering conversion — the Code gives kVA, the Electrical Code/engineer must convert to amps and select conductor/panel ratings.)
  3. Design action: Specify on plans a reserved transformer capacity of +400 kVA (or a transformer sized so spare capacity equals or exceeds 400 kVA), reserved panel/space and raceway(s)/busway sized to carry ~480 A per the chosen working voltage and conductor arrangement, and a documented pathway from that raceway termination point to each proposed charger location as required by § 5.106.5.5.1.

Important: the Code does not require a specific panel ampere rating (e.g., 600 A) in § 5.106.5.5.1; it requires that you provide the additional kVA capacity in the electrical distribution and raceway infrastructure. Final ampere ratings, conductor sizes, conduit counts and transformer selection must be sized under the California Electrical Code and coordinated with the utility.

Related provisions

  • § 5.106.5.5.1 — Electric vehicle charging readiness requirements for medium/heavy EVSE (primary controlling section).
  • § 5.106.5.5 — Electric vehicle (EV) charging: medium‑duty and heavy‑duty (exceptions and scope).
  • § 5.106.5.3.1 — EV capable spaces: minimum raceway trade size 1‑inch and panel capacity for 40 A branch circuits (useful for light‑duty guidance and for comparing minimum raceway practices).
  • § 5.106.5.3.6 — Raceway capacity requirements for low power Level 2 and related power allocation methods (useful when coordinating low‑power and higher‑power EV provisions).

Code references

Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:

  • § 5.106.5.5.1 High relevance — show source text

    5.106.5.5.1 Electric vehicle charging readiness requirements for warehouses, grocery stores, office buildings, and manufacturing facilities and retail stores with planned off-street loading spaces. [N] In order to avoid future demolition when adding EV supply and distribution equipment, spare raceway(s) or busway(s) and adequate capacity for transformer(s), service panel(s) or subpanel(s) shall be installed at the time of construction in accordance with the California Electrical Code . Construction plans and specifications shall include, but are not limited to, the following:

    1. The transformer, main service equipment and subpanels shall meet the minimum power requirement in Table 5.106.5.5.1 to accommodate the dedicated branch circuits for the future installation of EVSE.

    2. The construction documents shall indicate one or more location(s) convenient to the planned off-street loading space(s) reserved for medium- and heavy-duty ZEV charging cabinets and charging dispensers, and a pathway reserved for routing of conduit from the termination of the raceway(s) or busway(s) to the charging cabinet(s) and dispenser(s), as shown in Table 5.106.5.5.1.

    3. Raceway(s) or busway(s) originating at a main service panel or a subpanel(s) serving the area where potential future medium- and heavy-duty EVSE will be located and shall terminate in close proximity to the potential future location of the charging equipment for medium- and heavy-duty vehicles.

    4. The raceway(s) or busway(s) shall be of sufficient size to carry the minimum additional system load to the future location of the charging for medium- and heavy-duty ZEVs as shown in Table 5.106.5.5.1.

    TABLE 5.106.5.5.1—RACEWAY CONDUIT AND PANEL POWER REQUIREMENTS FOR MEDIUM- AND HEAVY-DUTY EVSE [N] Col2 Col3 Col4
    BUILDING TYPE BUILDING SIZE
    (SQ. FT.)    		 NUMBER OF OFF-STREET
    LOADING SPACES    		 ADDITIONAL CAPACITY REQUIRED (KVA) FOR
    RACEWAY & BUSWAY AND TRANSFORMER &
    PANEL
    Grocery 10,000 to 90,000 1 or 2 200
    Grocery 10,000 to 90,000 3 or Greater 400
    Grocery Greater than 90,000 1 or Greater 400
    Manufacturing
    Facilities    		 10,000 to 50,000 1 or 2 200
    Manufacturing
    Facilities    		 10,000 to 50,000 3 or Greater 400
    Manufacturing
    Facilities    		 Greater than 50,000 1 or Greater 400
    Office
    Buildings    		 10,000 to 135,000 1 or 2 200
    Office
    Buildings    		 10,000 to 135,000 3 or Greater 400
    Office
    Buildings    		 Greater than 135,000 1 or Greater 400
    Retail 10,000 to 135,000 1 or 2 200
    Retail 10,000 to 135,000 3 or Greater 400
    Retail Greater than 135,000 1 or Greater 400
    Warehouse 20,000 to 256,000 1 or 2 200
    Warehouse 20,000 to 256,000 3 or Greater 400
    Warehouse Greater than 256,
  • § 5.106.5.5 High relevance — show source text

    Install EVCS at all existing EV capable spaces, utilizing the existing allocated power and infrastructure for the total number of actual parking spaces being added or altered, prior to adding any new EV capable spaces. If the area being added or altered exceeds the existing EV capable capacity, allocated power and infrastructure, provide additional EV charging as needed to comply with this section.

    5.106.5.5 Electric vehicle (EV) charging: medium-duty and heavy-duty. [N] [BSG-CG] Construction shall comply with Section 5.106.5.5.1 to facilitate future installation of electric vehicle supply equipment (EVSE). Construction for warehouses, grocery stores and retail stores, office buildings, and manufacturing facilities with planned off-street loading spaces shall also comply with Section 5.106.5.5.1 for future installation of medium- and heavy-duty EVSE.

    Exceptions:

    1. On a case-by-case basis where the local enforcing agency has determined compliance with this section is not feasible based upon one of the following conditions: a. Where there is no local utility power supply. b. Where the local utility is unable to supply adequate power. c. Where there is evidence suitable to the local enforcing agency substantiating that additional local utility infrastructure design requirements, directly related to the implementation of Section 5.106.5.3, may adversely impact the construction cost of the project.

    2025 CALIFORNIA GREEN BUILDING STANDARDS CODE 5-7

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    NONRESIDENTIAL MANDATORY MEASURES

    When EVSE(s) is/are installed, it shall be in accordance with the California Building Code, the California Electrical Code and as follows:

    5.106.5.5.1 Electric vehicle charging readiness requirements for warehouses, grocery stores, office buildings, and manufacturing facilities and retail stores with planned off-street loading spaces. [N] In order to avoid future demolition when adding EV supply and distribution equipment, spare raceway(s) or busway(s) and adequate capacity for transformer(s), service panel(s) or subpanel(s) shall be installed at the time of construction in accordance with the California Electrical Code . Construction plans and specifications shall include, but are not limited to, the following:

    1. The transformer, main service equipment and subpanels shall meet the minimum power requirement in Table 5.106.5.5.1 to accommodate the dedicated branch circuits for the future installation of EVSE.

    2. The construction documents shall indicate one or more location(s) convenient to the planned off-street loading space(s) reserved for medium- and heavy-duty ZEV charging cabinets and charging dispensers, and a pathway reserved for routing of conduit from the termination of the raceway(s) or busway(s) to the charging cabinet(s) and dispenser(s), as shown in Table 5.106.5.5.1.

    3. Raceway(s) or busway(s) originating at a main service panel or a subpanel(s) serving the area where potential future medium- and heavy-duty EVSE will be located and shall terminate in close proximity to the potential future location of the charging equipment for medium- and heavy-duty vehicles.

    4. The raceway(s) or busway(s) shall be of sufficient size to carry the minimum additional system load to the future location of the charging for medium- and heavy-duty ZEVs as shown in Table 5.106.5.5.1.

  • § 5.106.5.3.1 High relevance — show source text

    1. Areas of parking facilities served by parking lifts, including but not limited to, automated mechanical-access open parking garages as defined in the California Building Code ; or parking facilities otherwise incapable of supporting electric vehicle charging. 5.106.5.3.1 EV capable spaces. [N] EV capable spaces shall be provided in accordance with Table 5.106.5.3.1 and the following requirements:

    2. Raceways complying with the California Electrical Code and no less than 1-inch (25 mm) diameter shall be provided and shall originate at a service panel or a subpanel(s) serving the area, and shall terminate in close proximity to the proposed location of the EV capable space and into a suitable listed cabinet, box, enclosure or equivalent. A common raceway may be used to serve multiple EV capable spaces.

    3. A service panel or subpanel(s) shall be provided with panel space and electrical load capacity for a dedicated 208/240 volt, 40-ampere minimum branch circuit for each EV capable space, with delivery of 30-ampere minimum to an installed EVSE at each EVCS.

    4. The electrical system and any on-site distribution transformers shall have sufficient capacity to supply full rated amperage at each EV capable space.

    5. The service panel or subpanel circuit directory shall identify the reserved overcurrent protective device space(s) as “EV CAPABLE”. The raceway termination location shall be permanently and visibly marked as “EV CAPABLE.” Note: A parking space served by electric vehicle supply equipment or designed as a future EV charging space shall count as at least one standard automobile parking space only for the purpose of complying with any applicable minimum parking space requirements established by an enforcement agency. See Vehicle Code Section 22511.2 for further details.

    TABLE 5.106.5.3.1—EV CAPABLE SPACES AND EVCS Col2 Col3 Col4
    TOTAL NUMBER OF ACTUAL
    PARKING SPACES    		 NUMBER OF REQUIRED EV
    CAPABLE SPACES    		 OTHER THAN OFFICE AND
    RETAIL
    NUMBER OF REQUIRED EVCS2, 3    		 OFFICE AND RETAIL
    NUMBER OF REQUIRED EVCS2, 3
    1–9 0 0 0
    10–25 4 2 3
    26–50 8 4 6
    51–75 13 6 8
    76–100 17 8 13
    101–150 25 12 19
    151–200 35 18 26
    201 and over 20 percent of actual parking
    spaces1    		 50 percent of EV capable spaces1 75 percent of EV capable spaces1
    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.    		 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.    		 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.    		 1.
  • § 5.106.5 High relevance — show source text

    5.106.5 Electric vehicle (EV) charging.

    5.106.5.1 Reserved.

    5.106.5.2 Reserved.

    5.106.5.3 Electric vehicle (EV) charging. [N] [BSC-CG] Construction to provide electric vehicle infrastructure and facilitate electric vehicle charging shall comply with Section 5.106.5.3.1 EV capable spaces, Section 5.106.5.3.2 Electric vehicle charging stations and associated Table 5.106.5.3.1, or Section 5.106.5.3.6 Electric vehicle charging stations (EVCS)—Power allocation method and associated Table 5.106.5.3.6, and shall be provided in accordance with regulations in the California Building Code and the California Electrical Code. Exceptions:

    1. On a case-by-case basis where the local enforcing agency has determined compliance with this section is not feasible based upon one of the following conditions: a. Where there is no local utility power supply. b. Where the local utility is unable to supply adequate power. c. Where there is evidence suitable to the local enforcement agency substantiating that additional local utility infrastructure design requirements, directly related to the implementation of Section 5.106.5.3, may adversely impact the construction cost of the project.

    2. Areas of parking facilities served by parking lifts, including but not limited to, automated mechanical-access open parking garages as defined in the California Building Code ; or parking facilities otherwise incapable of supporting electric vehicle charging. 5.106.5.3.1 EV capable spaces. [N] EV capable spaces shall be provided in accordance with Table 5.106.5.3.1 and the following requirements:

    3. Raceways complying with the California Electrical Code and no less than 1-inch (25 mm) diameter shall be provided and shall originate at a service panel or a subpanel(s) serving the area, and shall terminate in close proximity to the proposed location of the EV capable space and into a suitable listed cabinet, box, enclosure or equivalent. A common raceway may be used to serve multiple EV capable spaces.

    4. A service panel or subpanel(s) shall be provided with panel space and electrical load capacity for a dedicated 208/240 volt, 40-ampere minimum branch circuit for each EV capable space, with delivery of 30-ampere minimum to an installed EVSE at each EVCS.

    5. The electrical system and any on-site distribution transformers shall have sufficient capacity to supply full rated amperage at each EV capable space.

    6. The service panel or subpanel circuit directory shall identify the reserved overcurrent protective device space(s) as “EV CAPABLE”. The raceway termination location shall be permanently and visibly marked as “EV CAPABLE.” Note: A parking space served by electric vehicle supply equipment or designed as a future EV charging space shall count as at least one standard automobile parking space only for the purpose of complying with any applicable minimum parking space requirements established by an enforcement agency. See Vehicle Code Section 22511.2 for further details.

  • § 5.106.5.6.1 High relevance — show source text

    proposed location of the EV capable space and into a suitable listed cabinet, box, enclosure or equivalent. A common raceway may be used to serve multiple EV capable spaces. 2. A service panel or subpanel(s) shall be provided with panel space and electrical load capacity for a dedicated 208/240 volt, 40-ampere minimum branch circuit for each EV capable space, with delivery of 30-ampere minimum to an installed EVSE at each EVCS.

    1. The electrical system and any on-site distribution transformers shall have sufficient capacity to supply full rated amperage at each EV capable space.
    2. The service panel or subpanel circuit directory shall identify the reserved overcurrent protective device space(s) as “EV CAPABLE.” The raceway termination location shall be permanently and visibly marked as “EV CAPABLE.”
    TABLE 5.106.5.6.1 Col2 Col3
    TOTAL NUMBER OF PARKING SPACES NUMBER OF REQUIRED EV CAPABLE SPACES NUMBER OF REQUIRED EVCS2
    0–9 0 0
    10–25 4 1
    26–50 8 2
    51–75 13 3
    76–100 17 4
    101–150 25 6
    151–200 35 9
    201 and over 20 percent of total1 25 percent of EV capable spaces1
    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.    		 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.    		 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.

    5.106.5.6.2 Electric vehicle charging stations (EVCS). EV capable spaces shall be provided with EVSE to create EVCS in the number indicated in Table 5.106.5.6.1 and shall comply with Section 5.106.5.6.2. EVCS shall be serviced by Level 2 or Direct Current Fast Charging (DCFC) EVSE, or with EVSE in any combination of Level 2 and DCFC. Accessible EVCS shall be provided in accordance with California Building Code Chapter 11B .

    5.106.5.6.2.1 Reduced number of EV capable spaces. The installation of each DCFC EVSE shall be permitted to reduce the minimum number of required EV capable spaces indicated in Table 5.106.5.6.1 by five and reduce proportionally the required electrical load capacity to the service panel or subpanel.

    5.106.5.6.2.2 Multiple connectors. EVSE with multiple vehicle connectors capable of charging multiple EVs simultaneously shall be permitted if the electrical load capacity required by Section 5.106.5.6.1 for each EV capable space is accumulatively supplied to the EVSE.

  • § 6.6 High relevance — show source text

    6|Total required kVA = P× .30× 6.6
    Where P = Parking spaces in facility|Total required kVA = P× .30× 6.6
    Where P = Parking spaces in facility| |1. Level 2 EVSE @ 6.6 kVA minimum.
    2. At least one Level 2 EVSE shall be provided.
    3. Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|1. Level 2 EVSE @ 6.6 kVA minimum.
    2. At least one Level 2 EVSE shall be provided.
    3. Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|1. Level 2 EVSE @ 6.6 kVA minimum.
    2. At least one Level 2 EVSE shall be provided.
    3. Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|1. Level 2 EVSE @ 6.6 kVA minimum.
    2. At least one Level 2 EVSE shall be provided.
    3. Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|

    A5.106.5.3.3 Tier 2. Comply with Section 5.106.5.3.1 EV capable spaces, Section 5.106.5.3.2 Electric vehicle charging stations and associated Table A5.106.5.3.3, or Section A5.106.5.3.4 Electric vehicle charging stations (EVCS)—power allocation method and associated Table A5.106.5.3.4.

    Refer to Section 5.106.5.3.2 for the permitted use of Level 2 or Direct Current Fast Charger (DCFC) to create EVCS. Refer to Section 5.106.3.2.1 for the allowed use of DCFC to comply with both EV capable spaces and Level 2 EVSE. Refer to Section 5.106.5.3.3 for the allowed use of Automatic Load Management System (ALMS).

  • § 5.106.5.6 High relevance — show source text

    000 to 256,000|1 or 2|200| |Warehouse|20,000 to 256,000|3 or Greater|400| |Warehouse|Greater than 256,000|1 or Greater|400|

    5.106.5.6 Electric vehicle (EV) charging at public schools and community colleges. [DSA-SS] Electric vehicle infrastructure and electric vehicle charging stations shall comply with Section 5.106.5.6 and shall be provided in accordance with regulations in the California Building Code and the California Electrical Code.

    Exceptions:

    1. On a case-by-case basis where compliance with this section has been demonstrated to be not feasible based upon one of the following conditions, and with concurrence by the Division of the State Architect (DSA), compliance with Section 5.106.5.6 shall not be required. a. Where there is no local utility power supply. b. Where the local utility is unable to supply adequate power. c. The installation of EVCS is impracticable.
    2. Parking spaces accessible only by automated mechanical car parking systems are not required to comply with Section 5.106.5.6.

    5.106.5.6.1 EV capable spaces. EV capable spaces shall be provided in accordance with Table 5.106.5.6.1 and the following requirements:

    1. Raceways complying with the California Electrical Code and no less than 1-inch (25 mm) diameter shall be provided and shall originate at a service panel or a subpanel(s) serving the area and shall terminate in close proximity to the

    5-8 2025 CALIFORNIA GREEN BUILDING STANDARDS CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    NONRESIDENTIAL MANDATORY MEASURES

    proposed location of the EV capable space and into a suitable listed cabinet, box, enclosure or equivalent. A common raceway may be used to serve multiple EV capable spaces. 2. A service panel or subpanel(s) shall be provided with panel space and electrical load capacity for a dedicated 208/240 volt, 40-ampere minimum branch circuit for each EV capable space, with delivery of 30-ampere minimum to an installed EVSE at each EVCS.

    1. The electrical system and any on-site distribution transformers shall have sufficient capacity to supply full rated amperage at each EV capable space.
    2. The service panel or subpanel circuit directory shall identify the reserved overcurrent protective device space(s) as “EV CAPABLE.” The raceway termination location shall be permanently and visibly marked as “EV CAPABLE.”
    TABLE 5.106.5.6.1 Col2 Col3
    TOTAL NUMBER OF PARKING SPACES NUMBER OF REQUIRED EV CAPABLE SPACES NUMBER OF REQUIRED EVCS2
    0–9 0 0
    10–25 4 1
    26–50 8 2
    51–75 13 3
    76–100 17 4
    101–150 25 6
    151–200 35 9
    201 and over 20 percent of total1 25 percent of EV capable spaces1
    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.    		 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.    		 1.
  • California Energy Code High relevance — show source text
    1. Single main service panels fed by single transformer

    Example 1

    480 V, 4-wire, 1,600-amp rated main switch, initial demand load is 300 kVA. Install five 5-inch ducts, service size is 1,000 kcmil for phase and 350 kcmil for neutral. Only two sets of service conductors are required to meet initial loading. The remaining three ducts should be capped for future use.

    Rev. #26: 03−25−22 063928 Page 3 of 9

    UG-1: Services Greenbook EDM

    Methods and Requirements for Installing Non-Residential Underground Electric Services 0 − 600 Volts to Customer-Owned Facilities

    1. Multiple main service panels fed by single transformer

    Example 2

    1,000-amp, 600-amp, and 400-amp mains to be served. The number of sets of conduits required are three, two, and one, respectively. A total of six conduits are needed to serve the three main switches. The three services can be served from one transformer.

    1. Multiple main service panels fed by multiple transformers

    Example 3

    2,000-amp and 1,000-amp mains to be served. The number of sets of conduits required are seven and three respectively. A total of ten conduits are needed to serve the two main switches. The two services cannot be served from one transformer; they must be served from individual transformers.

    Cover

    1. A minimum of 24 inches of cover for secondary (0 − 750 V) electric service, or 36 inches minimum cover for primary (over 750 V) is required. Cover is the distance from the outer surface of an underground facility to the top of the final grade . The ac tual trench dept h will be greater (approximately 30 inches or 42 inches minimum respectively) to accommodate the under ground facility, bedding, enclosures, riser sweeps, and joint trench installations with other utilities.

    Upgraded Panel

    1. For upgraded panels where the new specified size of service conductor will fit in the existing conduit, it is not necessary to upgrade the conduit to the currently specified size and number for the new panel if all of the following are met:

    A. The maximum conduit fill ratio is not exceeded.

    B. The calculated cable pulling tensions along the conduit route is within limits of the new cable.

    C. Copper or larger size Aluminum cable can handle full load in existing number of conduits. See Table 1 and Table 2 below.

    Table 1 Service Cabled Size Allowed in Existing Conduit When Upgrading Single Phase Panels

    Existing Service
    Equipment
    Rating (amps)    		 New Upgrade
    Service
    Equipment
    Rating (amps)    		 Minimum
    Allowed Existing
    Conduit Size
    and Number    		 Aluminum or Copper Cable
    Required to Serve Maximum
    Load AWG or kcmil1    		 Col5
    Existing Service
    Equipment
    Rating (amps)    		 New Upgrade
    Service
    Equipment
    Rating (amps)    		 Minimum
    Allowed Existing
    Conduit Size
    and Number    		 (Per Phase) Neutral
    100 200 1−3” 1−4/0 Al 1−1/0 Al
    200 400 1−3” 1−750 Al 1−4/0 Al
    400 600 1−4” 1−1000 Cu2,3 1−250 Cu
  • § 5.106.5.3.1 High relevance — show source text

    Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|1. Level 2 EVSE @ 6.6 kVA minimum.
    2. At least one Level 2 EVSE shall be provided.
    3. Maximum allowed kVA to be utilized for EV capable spaces is 67 percent.
    4. If EV capable spaces are utilized, they shall meet the requirements of Section 5.106.5.3.1 EV capable spaces.
    5. For office and retail buildings the maximum allowed kVA to be utilized for EV capable spaces is 25 percent.|

    A5.106.5.3.3 Tier 2. Comply with Section 5.106.5.3.1 EV capable spaces, Section 5.106.5.3.2 Electric vehicle charging stations and associated Table A5.106.5.3.3, or Section A5.106.5.3.4 Electric vehicle charging stations (EVCS)—power allocation method and associated Table A5.106.5.3.4.

    Refer to Section 5.106.5.3.2 for the permitted use of Level 2 or Direct Current Fast Charger (DCFC) to create EVCS. Refer to Section 5.106.3.2.1 for the allowed use of DCFC to comply with both EV capable spaces and Level 2 EVSE. Refer to Section 5.106.5.3.3 for the allowed use of Automatic Load Management System (ALMS).

    TABLE A5.106.5.3.3—TIER 2 EV CAPABLE SPACES AND EVCS Col2 Col3 Col4
    TOTAL NUMBER OF
    ACTUAL PARKING SPACES    		 NUMBER OF
    REQUIRED EV CAPABLE SPACES    		 OTHER THAN OFFICE AND RETAIL
    NUMBER OF REQUIRED EVCS2, 3    		 OFFICE AND RETAIL
    NUMBER OF REQUIRED EVCS2, 3
    1–9 3 2 2
    10–25 8 4 6
    26–50 17 9 13
    51–75 28 14 21
    76–100 40 20 30
    101–150 57 29 43
    151–200 79 40 59
    201 and over 45 percent of actual parking spaces1 50 percent of EV capable spaces1 75 percent of EV capable spaces1
    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.    		 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.    		 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.    		 1.
  • California Energy Code High relevance — show source text

    Figure 1 Conduit Installation in a Drain Box

    (2) For indoor electric meter rooms below grade level, a reliable method of water mitigation and drainage must be incorporated into the design of the meter room(s) to prevent the accumulation of water. 15. When service termination/connections are made at the customer termination can or pull section, whether the serviced is left energized or de-energized,

    A. Cover and seal all meter sockets with an approved blank-off cover (Pie Plate) or set the electric meter(s). Material codes for electric meter socket covers are M249424 and M249559 .

    B. Seal all seal-able covers on the customer owned panel using PG&E approved seals.

    1. Minimum service requirements

    A. Install the number and size of conduits as shown in Table 4 on Page 6 and Table 5 on Page 7, based on the main service panel rating. No more than seven service conduits, of any size, will be supplied from any one transformer.

    B. Install the number and size of conductors, as shown in Table 4 on Page 6, to meet the individual initial demand load. Take load characteristics and growth into consideration. C. It is permissible to install a smaller transformer and fewer conductors to serve a long term initial load with the intent of installing a larger transformer and additional conductors should future load increase occur. D. Always size the transformer pad to accommodate the largest transformer size necessary to serve the combined ampacity of all services. Never exceed more than seven sets of conductors per transformer. E. Vacant ducts, if any, are to be used to serve future load increases.

    1. Single main service panels fed by single transformer

    Example 1

    480 V, 4-wire, 1,600-amp rated main switch, initial demand load is 300 kVA. Install five 5-inch ducts, service size is 1,000 kcmil for phase and 350 kcmil for neutral. Only two sets of service conductors are required to meet initial loading. The remaining three ducts should be capped for future use.

    Rev. #26: 03−25−22 063928 Page 3 of 9

    UG-1: Services Greenbook EDM

    Methods and Requirements for Installing Non-Residential Underground Electric Services 0 − 600 Volts to Customer-Owned Facilities

    1. Multiple main service panels fed by single transformer

    Example 2

    1,000-amp, 600-amp, and 400-amp mains to be served. The number of sets of conduits required are three, two, and one, respectively. A total of six conduits are needed to serve the three main switches. The three services can be served from one transformer.

    1. Multiple main service panels fed by multiple transformers

    Example 3

    2,000-amp and 1,000-amp mains to be served. The number of sets of conduits required are seven and three respectively. A total of ten conduits are needed to serve the two main switches. The two services cannot be served from one transformer; they must be served from individual transformers.

    Cover

  • § 112.5 Medium relevance — show source text

    5 through1,000 kVA)|3Ø UCD
    (112.5 through1,000 kVA)|Yes2|4’ 6” x 8’ 6” x 7’ 6”|6’ 6” x 10’ 6” x 9’|6’ 6” x 10’ 6” x 10’|

    1 Depth allows for 6” of drain rock, per Note 5D. on Page 1. 2 Installing this equipment in heavy full-traffic enclosures is the least desirable option, and should only be considered on reconstruction projects where suitable locations for incidental and full vehicle traffic boxes are not available. Refer to Item 25 in the Application section of this document. 3 See Document 051776. 4 The 12” extension that is included in the heavy full-traffic assembly is not listed in this column. 5 Installation of a 3’x5’x3’6” enclosure for straight splices is only allowed if no future expansion is expected that would require a transformer, junction, or switch to be installed in that enclosure. 6 1 Ø Round transformers require a 6’ deep enclosure; add a 12” extension to the standard enclosure.

    062000 Page 4 of 26 Rev. #25: 03-25-22

    UG-1: Enclosures Greenbook Primary Electric Underground Enclosures

    Notes

    1. Existing 3’ x 5’ (#5) enclosure with minimum 36” depth will continue to be allowed when:

    A. Replacing existing 200-Amp splice junction, and equipment.

    B. Converting existing 200-Amp splices to a 200-Amp junction.

    1. When intercepting existing 200-Amp primary cable to install 200-Amp equipment, the installation of a 3’ x 5’ (#5) enclosure will only be allowed if there is no physical space for the installation of a 4’ x 6’ 6” (#6) enclosure and all other design alternatives have been exhausted. However, installation of 167 kVA single phase transformers requires a 4’ x 6’ 6” (#6) enclosure.

    2. The installation of new 200-Amp junction and equipment is not allowed in new 3’ x 5’ (#5) primary enclosure for new PG&E job estimates or Applicant Design (AD) estimates.

    Rev. #25: 03-25-22 062000 Page 5 of 26

    UG-1: Enclosures Greenbook Primary Electric Underground Enclosures

    3’ 0” x 5’ 0” (#5) Complete Enclosure Assemblies (incidental transformer cover shown)

    Figure 1 Isometric View of 3’ x 5’ Enclosure Assembly (not to scale)

    Table 2 Complete Enclosure Assembly (for 200-Amp distribution)

  • § 5.106.5.4.1 Medium relevance — show source text

    Remote parking facilities that do not have access to the building service panel. 3. Parking area lighting upgrades where no trenching is part of the scope of work. 4. Emergency repairs, including but not limited to water line break in parking facilities, natural disaster repairs, etc.

    5.106.5.4.1 Existing buildings or parking areas without previously installed EV capable infrastructure [A]. When EV capable infrastructure does not exist at an existing parking facility or building, and the parking facility or building undergoes an addition or alteration listed in Section 5.106.5.4, construction shall include electric vehicle charging in compliance with either Section 5.106.5.3 and associated Table 5.106.5.3.1, or Section 5.106.5.3.6 and associated Table 5.106.5.3.6 for the total number of actual parking spaces being added or altered.

    5.106.5.4.2 Existing buildings or parking areas with previously installed EV capable infrastructure [A]. When EV capable infrastructure is available at an existing parking facility or building, and the parking facility or building is undergoing an addition or alteration listed in Section 5.106.5.4, construction shall include electric vehicle charging in compliance with either Section 5.106.5.3 and associated Table 5.106.5.3.1, or Section 5.106.5.3.6 and associated Table 5.106.5.3.6. Install EVCS at all existing EV capable spaces, utilizing the existing allocated power and infrastructure for the total number of actual parking spaces being added or altered, prior to adding any new EV capable spaces. If the area being added or altered exceeds the existing EV capable capacity, allocated power and infrastructure, provide additional EV charging as needed to comply with this section.

    5.106.5.5 Electric vehicle (EV) charging: medium-duty and heavy-duty. [N] [BSG-CG] Construction shall comply with Section 5.106.5.5.1 to facilitate future installation of electric vehicle supply equipment (EVSE). Construction for warehouses, grocery stores and retail stores, office buildings, and manufacturing facilities with planned off-street loading spaces shall also comply with Section 5.106.5.5.1 for future installation of medium- and heavy-duty EVSE.

    Exceptions:

    1. On a case-by-case basis where the local enforcing agency has determined compliance with this section is not feasible based upon one of the following conditions: a. Where there is no local utility power supply. b. Where the local utility is unable to supply adequate power. c. Where there is evidence suitable to the local enforcing agency substantiating that additional local utility infrastructure design requirements, directly related to the implementation of Section 5.106.5.3, may adversely impact the construction cost of the project.

    2025 CALIFORNIA GREEN BUILDING STANDARDS CODE 5-7

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    NONRESIDENTIAL MANDATORY MEASURES

    When EVSE(s) is/are installed, it shall be in accordance with the California Building Code, the California Electrical Code and as follows:

Frequently asked questions

What exactly must I show on the construction drawings?

Show the reserved transformer/panel additional kVA per Table 5.106.5.5.1, the proposed location(s) for charging cabinets/dispensers, and a reserved pathway from the raceway/busway termination to those locations as required by § 5.106.5.5.1.

Does the Code tell me the conduit diameter to run for medium/heavy EVSE?

No. § 5.106.5.5.1 requires raceways or busways be sized to carry the additional kVA in the table; the Code does not prescribe a specific conduit diameter for medium/heavy EVSE — conduit sizing and conductor ampacity must be developed per the California Electrical Code and project engineering.

If I install the spare raceway now, do I still need to upgrade the transformer later?

You must provide transformer/panel capacity equal to the additional kVA in Table 5.106.5.5.1 at the time of construction. If your initial transformer does not provide that reserved capacity, you will likely need a transformer upgrade when EVSE is installed; the Code requires reserving the capacity now so upgrades (and demolition) are avoided.

Are there situations where I don’t have to comply?

Yes — the local enforcing agency may allow exceptions when there is no utility supply, the utility cannot supply adequate power, or additional utility infrastructure requirements would unreasonably impact project cost, per the exceptions to § 5.106.5.5.

For light‑duty EV capable spaces, what raceway size is required?

For light‑duty EV capable spaces the Code requires raceways no less than 1‑inch (25 mm) trade size originating at the service or subpanel (see § 5.106.5.3.1). That minimum helps with Level 2 provisioning, but medium/heavy requirements in § 5.106.5.5.1 must be followed for loading areas.

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What are the EV charging readiness requirements for warehouses, grocery/retail, office and manufacturing loading spaces?

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Medium‑ and heavy‑duty EV charging readiness

California Energy Code