Title 24 · California Energy Code
How do energy budgets differ for nonresidential, single‑family, and multifamily buildings?
In plain terms: to use the performance path you run the proposed design and the standard design in CEC‑certified software and must show the proposed building’s annual energy (measured as Long‑Term System Cost and Source Energy) is no greater than the standard design’s budget. Nonresidential (§140.1), single‑family (§150.1), and multifamily (§170.1) all follow that same test but differ in which components are included in Efficiency vs Total LSC, how PV/BESS and self‑utilization are credited, and special exceptions (for example, multifamily source energy has a gas‑water‑heater caveat and additions/alterations are evaluated on LSC only).
Last reviewed: July 6, 2026
What the code requires — 2–4 sentences
The heart of the performance path is the simple test: the proposed design building’s energy use must not exceed the standard design building’s energy budget as calculated in Commission‑certified software. For nonresidential buildings this is the performance test in § 140.1; for single‑family residential buildings it is § 150.1; and for multifamily buildings it is § 170.1. All three express energy budgets in Long‑Term System Cost (LSC) and Source Energy, but there are important differences in how components are composed, exceptions, and how additions/alterations are handled.
The single most important rule: a building satisfies the performance approach when the calculated annual energy consumption of the proposed design is no greater than the energy budget of the standard design, using Commission‑certified compliance software (LSC and source energy as applicable).
Requirements in detail
High‑level commonality (all three performance sections)
- The same compliance concept: compare the proposed design to the standard design using CEC‑certified software. Energy budget is the metric.
- Energy budgets are expressed in Long‑Term System Cost (LSC) and Source Energy for newly constructed buildings; additions and alterations budgets are expressed in LSC. See the procedure overview in § 100.2.
Key definitions (bolded on first use)
- Energy budget — the maximum allowable annual energy consumption for the proposed design compared to the standard design.
- Long‑Term System Cost (LSC) — an hourly, monetary‑weighted metric that multiplies site energy by CEC LSC hourly factors (varies by hour, energy type, climate zone, and building type). See § 100.2.
- Source Energy — site energy multiplied by source (Btu) factors representing upstream fossil fuel and electric system resource impacts.
- Efficiency LSC and Total LSC — Efficiency LSC sums LSC for space‑conditioning, water heating, mechanical ventilation, (and lighting where specified); Total LSC adds PV, BESS, demand flexibility and other loads as applicable. (See each occupancy § below.)
Decision‑relevant differences (quick reference table)
| Decision dimension | Nonresidential (§ 140.1) | Single‑family (§ 150.1) | Multifamily (§ 170.1) | Code Reference |
|---|---|---|---|---|
| Which section sets the performance test | § 140.1 | § 150.1 | § 170.1 | |
| Energy budget units for new construction | LSC and Source Energy | LSC and Source Energy (explicitly defined) | LSC and Source Energy (source energy calc has a gas‑water‑heater caveat) | |
| Components in Efficiency LSC | Space‑conditioning, water heating, mechanical ventilation, lighting (per § 140.1) | Space‑conditioning, water heating, mechanical ventilation, self‑utilization credit explained in Residential ACM | Space‑conditioning, water heating, mechanical ventilation, lighting, self‑utilization credit | |
| Components in Total LSC | Efficiency LSC + PV + BESS + demand flexibility + (other plug loads) | Efficiency LSC + PV + BESS + lighting + demand flexibility + other plug loads (Total LSC defined in § 150.1) | Efficiency LSC + PV + BESS + demand flexibility (Total LSC defined in § 170.1) | |
| Additions / Alterations | Energy budgets for additions/alterations are expressed in LSC (not source) per § 100.2. | Additions treated under Sections for additions — budgets expressed in LSC; see § 150.1 notes and Section 180 for additions/alterations handling. | Same — additions/alterations budgets expressed in LSC; see § 170.1 and § 180.1/180.2 for procedures. | |
| Climate zone / LSC hourly factors | LSC hourly factors vary by hour, energy type, Climate Zone and building type — factors are in Reference Joint Appendix JA3 and used by compliance software. | Same (LSC factors and climate zone rules apply). | Same (LSC factors and climate zone rules apply). | |
| Special calculation note | Community‑shared PV/BESS may offset required LSC energy per exceptions in § 140.1. | Residential ACM provides self‑utilization credit rules; community shared solar/BESS exception also allowed. | Source energy budget exception: source energy calc is determined as stated except with a consumer gas or propane water heater — see § 170.1(a)2. |
Notes on table items
- The LSC/Source Energy units are common across occupancy types for new construction, but the list of included components and the way credits (self‑utilization, PV/BESS, demand flexibility) are applied differ and are explicitly spelled out in each occupancy section.
- The detailed hourly LSC factors are not listed in the sections themselves but are provided in Reference Joint Appendix JA3 and used by the software; the code text explains the method in § 100.2.
How the LSC and Source budgets are composed (short bullets)
- LSC: calculated hourly by multiplying site energy (kWh, therms, gallons) by CEC LSC hourly factors (hour, energy type, climate zone, building type). § 100.2 describes the method.
- Source Energy: calculated hourly by multiplying site energy by source (Btu) factors reflecting upstream fossil fuel and the marginal electric resource mix. § 100.2.
- The occupancy sections define what goes into Efficiency LSC vs Total LSC. For example, single‑family Efficiency LSC sums space‑conditioning, water heating, mechanical ventilation and the self‑utilization credit; Total LSC adds PV, BESS, lighting, demand flexibility and other plugs. § 150.1(b)1.
Exceptions & special cases
- Community shared solar / BESS offset: A community shared solar electric generation system and/or community shared BESS that meets Energy Commission approval can offset part or all of the PV/BESS LSC energy otherwise required to comply. This exception is explicitly stated in § 140.1(a), § 150.1(b), and § 170.1(a).
- Additions and alterations: Energy budgets for additions and alterations are expressed in LSC (not source energy). The general method and the fact the energy budgets for additions/alterations are LSC‑based are explained in § 100.2 and the applicable additions sections (e.g., § 180.1 for multifamily additions).
- Multifamily source energy caveat: When calculating the source energy budget for multifamily buildings, the code instructs the source energy calculation is determined by the standard design “except with a consumer gas or propane water heater” — i.e., there is a specific treatment when consumer gas/propane water heaters are present; see § 170.1(a)2.
- Climate zone handling: If a single development spans multiple climate zones, the developer may design all buildings to the climate zone that contains 50 percent or more of the dwelling units (exceptions in § 150.1 and § 170.0).
Common mistakes
- Treating Source Energy and LSC as interchangeable: they are different metrics (LSC uses CEC hourly cost factors; source energy uses Btu factors) and both must be checked where required. See § 100.2 and the applicable occupancy section.
- Forgetting that additions/alterations budgets are expressed in LSC only — many practitioners try to compare source energy for an addition when the code requires LSC. See § 100.2.
- Omitting PV/BESS or self‑utilization credits from the Total LSC (or applying them incorrectly). Each occupancy section specifies what belongs in Efficiency vs Total LSC; read § 140.1, § 150.1, and § 170.1 carefully.
- Ignoring the community shared solar/BESS exception or using an unapproved offset method — these offsets require Energy Commission approval as described in the sections.
- Not including required documentation for permit applications — for multifamily, § 170.1(b) requires documentation (Certificate of Compliance and field verification evidence).
Worked example — concrete scenario (illustrative numbers)
Scenario (simplified and illustrative only): a new small office building (nonresidential) with the following annual site energy use estimates for the proposed design:
- Electricity: 100,000 kWh/year
- Natural gas: 6,000 therms/year
Step 1 — Standard design (software) produces standard annual LSC = $120,000 and standard annual source energy = 1,500,000,000 Btu.
Step 2 — Proposed design LSC calculation (using the same LSC hourly factors) yields proposed annual LSC = $110,000 and proposed source energy = 1,420,000,000 Btu.
Compliance check:
- LSC: proposed $110,000 ≤ standard $120,000 → pass (LSC compliance).
- Source Energy: proposed 1.42e9 Btu ≤ standard 1.5e9 Btu → pass (source energy compliance).
Notes and caveats:
- This numeric example is illustrative only. The code requires using Commission‑certified compliance software which applies the official LSC hourly factors (Reference Joint Appendix JA3) and official source Btu factors. You must run the approved software to get the official LSC and source numbers for your project — see § 100.2 and the occupancy performance section (e.g., § 140.1 for nonresidential).
- If the building includes PV and BESS, those systems are included in Total LSC and may change the Total LSC calculation (see occupancy section definitions for how PV/BESS and self‑utilization are credited).
Related provisions
- § 100.2 — Calculation of energy budgets (defines LSC & Source Energy, and notes LSC hourly factors / JA3).
- § 110.10 — Solar readiness / solar zone (affects PV/BESS planning which influences Total LSC).
- § 140.2 — Prescriptive approach for nonresidential (alternative to § 140.1 performance).
- § 141.0 — Additions, alterations and repairs to existing nonresidential / hotel/motel buildings (affects how performance rules apply to modifications).
- § 150.2 and § 180.1 / § 180.2 — Specifics for additions/alterations for single‑family and multifamily projects (see the residential/multifamily subchapters).
- Reference Joint Appendix JA3 — contains the LSC hourly factors used by compliance software (see § 100.2).
Code references
Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:
§ 100.2 High relevance — show source text
SECTION 100.2—CALCULATION OF ENERGY BUDGETS
Energy budgets are adopted by the Commission to establish the maximum energy consumption that a proposed building, or portion of a building, can be designed to consume. A building complies with the performance standards compliance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by the Alternative Calculation Methods Reference Manual. The energy budget for newly constructed single-family, multifamily, and nonresidential buildings are expressed in terms of Long-Term System Cost (LSC) and Source Energy. The energy budget for additions and alterations for all building types are expressed in terms of LSC.
Long-term System Cost (LSC) is calculated by multiplying for each hour of the year the site energy use (electricity kWh, natural gas therms, or fuel oil or LPG gallons) for each energy type by the applicable CEC-published LSC hourly factors. LSC hourly factors vary for each hour of the year and by energy type (electricity, natural gas, or propane), by Climate Zone and by building type (residential, nonresidential). LSC hourly factors are summarized in Reference Joint Appendix JA3. LSC hourly factors for propane are used for all energy obtained from depletable sources other than electricity and natural gas.
Source Energy is calculated by multiplying for each hour of the year the site energy use (electricity kWh, natural gas therms, or fuel oil or LPG gallons) by Btu factors for fossil fuel consumed either directly at the building site or caused to be consumed to meet the electrical demand of the building considering the long-term marginal hourly resources of Commission-projected electric system resource procurement.
Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
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ALL OCCUPANCIES—GENERAL PROVISIONS
FIGURE 100.1-A CALIFORNIA CLIMATE ZONES
Climate Zones for Residential and Nonresidential Occupancies
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2 ALL OCCUPANCIES—MANDATORY REQUIREMENTS FOR THE
MANUFACTURE, CONSTRUCTION AND INSTALLATION OF SYSTEMS, EQUIPMENT AND BUILDING COMPONENTS
SECTION 110.0—SYSTEMS AND EQUIPMENT—GENERAL
Sections 110.1 through 110.12 specify requirements for manufacturing, construction and installation of certain systems, equipment, appliances and building components that are installed in buildings within the scope of Section 100.0(a).
Note: The requirements of Sections 110.0 through 110.12 apply to newly constructed buildings. Sections 141.0 and 150.2 specify which requirements of Sections 110.1 through 110.12 also apply to additions and alterations to existing buildings.
§ 140.4 High relevance — show source text
MULTI-PASS WATER HEATER is a water heater that the cold water passes through multiple times. The water temperature increases with each pass until the storage tank reaches the intended storage temperature.
SINGLE-PASS WATER HEATER is a water heater which the cold water passes through once and is heated to the intended use temperature.
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ALL OCCUPANCIES—GENERAL PROVISIONS
WEST-FACING (See “orientation.”)
WINDOW FILM is a fenestration attachment product that consists of a flexible adhesive-backed polymer film, which may be applied to the interior or exterior surface of an existing glazing system.
WOOD HEATER is an enclosed wood-burning appliance used for space heating and/or domestic water heating.
WOOD STOVE (See “wood heater.”)
ZONAL describes characterized by or relating to a zone or zones.
ZONE, CRITICAL is a zone serving a process where reset of the zone temperature setpoint during a demand shed event might disrupt the process, including but not limited to computer rooms, data centers, telecom and private branch exchange (PBX) rooms, and laboratories.
ZONE, NONCRITICAL is a zone that is not a critical zone.
ZONE, SPACE-CONDITIONING, is a space or group of spaces within a building with sufficiently similar comfort conditioning requirements so that comfort conditions, as specified in Section 140.4(b)3 or 150.0(h), as applicable, can be maintained throughout the zone by a single controlling device.
SECTION 100.2—CALCULATION OF ENERGY BUDGETS
Energy budgets are adopted by the Commission to establish the maximum energy consumption that a proposed building, or portion of a building, can be designed to consume. A building complies with the performance standards compliance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by the Alternative Calculation Methods Reference Manual. The energy budget for newly constructed single-family, multifamily, and nonresidential buildings are expressed in terms of Long-Term System Cost (LSC) and Source Energy. The energy budget for additions and alterations for all building types are expressed in terms of LSC.
Long-term System Cost (LSC) is calculated by multiplying for each hour of the year the site energy use (electricity kWh, natural gas therms, or fuel oil or LPG gallons) for each energy type by the applicable CEC-published LSC hourly factors. LSC hourly factors vary for each hour of the year and by energy type (electricity, natural gas, or propane), by Climate Zone and by building type (residential, nonresidential). LSC hourly factors are summarized in Reference Joint Appendix JA3. LSC hourly factors for propane are used for all energy obtained from depletable sources other than electricity and natural gas.
Source Energy is calculated by multiplying for each hour of the year the site energy use (electricity kWh, natural gas therms, or fuel oil or LPG gallons) by Btu factors for fossil fuel consumed either directly at the building site or caused to be consumed to meet the electrical demand of the building considering the long-term marginal hourly resources of Commission-projected electric system resource procurement.
§ 130.5 Medium relevance — show source text
Exception 2 to Section 130.5(d): Receptacles in healthcare facilities.
(e) Demand responsive controls and equipment. See Section 110.12 for requirements for demand responsive controls and equipment, including demand responsive controls for controlled receptacles.
Note: Definitions of terms and phrases in Section 130.5 are determined as specified in Section 100.1(b). Terms and phrases not found in Section 100.1(b) shall be defined as specified in Title 24, Part 3, Article 100 of the California Electrical Code.
Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code.
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5 NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—
PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY
SECTION 140.0—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
Nonresidential and hotel/motel buildings shall comply with all of the following: (a) The requirements of Sections 100.0 through 110.12 applicable to the building project (mandatory measures for all buildings). (b) The requirements of Sections 120.0 through 130.5 (mandatory measures for nonresidential and hotel/motel buildings). (c) Either the performance compliance approach (energy budgets) specified in Section 140.1 or the prescriptive compliance approach specified in Section 140.2 for the climate zone in which the building will be located. Climate zones are shown in Figure 100.1-A.
Note to Section 140.0(c): The Commission periodically updates, publishes and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, which is available by zip code boundaries depicted in the Reference Joint Appendices along with a list of the communities in each zone.
Note to Section 140.0: The requirements of Sections 140.1 through 140.10 apply to newly constructed buildings. Section 141.0 specifies which requirements of Sections 140.1 through 140.10 also apply to additions or alterations to existing buildings.
Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code.
SECTION 140.1—PERFORMANCE APPROACH: ENERGY BUDGETS
A building complies with the performance standards if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.
§ 130.2 Medium relevance — show source text
130.2 Outdoor Lighting Controls and Equipment . . . . . . .100
130.3 Sign Lighting Controls. . . . . . . . . . . . . . . . . . . . . . . . . .101
130.4 Lighting Control Acceptance and Installation Certificate Requirements. . . . . . . . . . . . . . . . . . . . . .101
130.5 Electrical Power Distribution Systems . . . . . . . . . . .102
SUBCHAPTER 5 NONRESIDENTIAL AND
HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND
PRESCRIPTIVE COMPLIANCE APPROACHES FOR
ACHIEVING ENERGY EFFICIENCY. . . . . . . . . . . . . . . . . . . . 105
140.0 Performance and Prescriptive Compliance Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
140.1 Performance Approach: Energy Budgets . . . . . . . . .105
140.2 Prescriptive Approach . . . . . . . . . . . . . . . . . . . . . . . . .105
140.3 Prescriptive Requirements for Building Envelopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
140.4 Prescriptive Requirements for Space-Conditioning Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114
140.5 Prescriptive Requirements for Service Water-Heating Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
140.6 Prescriptive Requirements for Indoor Lighting. . . .130
140.7 Prescriptive Requirements for Outdoor Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
140.8 Prescriptive Requirements for Signs . . . . . . . . . . . . .141
140.9 Prescriptive Requirements for Covered
Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141
140.10 Prescriptive Requirements for Photovoltaic and Battery Energy Storage Systems . . . . . . . . . . . . . . .145
SUBCHAPTER 6 NONRESIDENTIAL AND
HOTEL/MOTEL OCCUPANCIES—ADDITIONS, ALTERATIONS
AND REPAIRS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
141.0 Additions, Alterations and Repairs to Existing Nonresidential and Hotel/Motel Buildings, to Existing Outdoor Lighting, and to Internally and Externally Illuminated Signs . . . . . . . . . . . . . . . . . . .149
141.1 Requirements for Covered Processes in Additions, Alterations to Existing Nonresidential and Hotel/Motel Buildings. . . . . . . . . . . . . . . . . . . . . . . . .157
§ 120.0 Medium relevance — show source text
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ii. Compliance approaches. In order to comply with Part 6, newly constructed nonresidential buildings and hotels/motels that are mechanically heated or mechanically cooled must meet the requirements of: a. Mandatory measures: The applicable provisions of Sections 120.0 through 130.5; and
b. Either:
(i) Performance approach: Section 140.1; or (ii) Prescriptive approach: Sections 140.2 through 140.10. C. Unconditioned nonresidential buildings and process space. Sections 110.9, 110.10, 120.6, 130.0 through 130.5, 140.3(c), 140.6, 140.7 and 140.8 apply to all newly constructed unconditioned buildings and for process spaces within the scope of Section 100.0(a). D. Single-family buildings. i. Sections applicable. Sections 150.0 through 150.1 apply to newly constructed single-family buildings. ii. Compliance approaches. In order to comply with Part 6, newly constructed single-family buildings must meet the requirements of: a. Mandatory measures: The applicable provisions of Sections 110.0 through 110.10 and 150.0; and
b. Either:
(i) Performance approach: Sections 150.1(a) and (b); or (ii) Prescriptive approach: Sections 150.1(a) and (c). Exception to Section 100.0(e)2Diib: Seasonally occupied agricultural housing limited by state or federal agency contract to occupancy not more than 180 days in any calendar year. E. Multifamily Buildings . i. Sections applicable. Sections 160.0 through 170.2 apply to newly constructed multifamily buildings. ii. Compliance approaches. In order to comply with Part 6, newly constructed multifamily buildings must meet the requirements of: a. Mandatory measures: The applicable provisions of Sections 110.0 through 110.10, and 160.0; and
b. Either:
(i) Performance approach: Section 170.1; or (ii) Prescriptive approach: Section 170.2(a) through (f).
F. Covered processes.
i. Sections applicable. Sections 110.2, 120.3, 120.6, 140.9, and 141.1 apply to covered processes. ii. Compliance approaches. In order to comply with Part 6, covered processes must meet the requirements of: a. The applicable mandatory measures in Sections 110.2, 120.3 and 120.6; and
b. Either:
(i) The performance approach requirements of Section 140.1; or (ii) The prescriptive approach requirements of Section 140.9. 3. New construction in existing buildings (additions, alterations and repairs). A. Nonresidential and hotel/motel buildings. Section 141.0 applies to new construction in existing nonresidential, high-rise residential and hotel/motel buildings. New construction in existing buildings includes additions, alterations and repairs. Section 141.0 specifies requirements that uniquely apply to additions, alterations or repairs to existing buildings, and specify which requirements in other sections also apply. For alterations that change the occupancy classification of the building, the requirements specified in Section 141.0 apply to the occupancy after the alterations. B. **Single-family buildings.
§ 140.6 Medium relevance — show source text
140.6 Prescriptive Requirements for Indoor Lighting. . . .130
140.7 Prescriptive Requirements for Outdoor Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138
140.8 Prescriptive Requirements for Signs . . . . . . . . . . . . .141
140.9 Prescriptive Requirements for Covered
Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141
140.10 Prescriptive Requirements for Photovoltaic and Battery Energy Storage Systems . . . . . . . . . . . . . . .145
SUBCHAPTER 6 NONRESIDENTIAL AND
HOTEL/MOTEL OCCUPANCIES—ADDITIONS, ALTERATIONS
AND REPAIRS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
141.0 Additions, Alterations and Repairs to Existing Nonresidential and Hotel/Motel Buildings, to Existing Outdoor Lighting, and to Internally and Externally Illuminated Signs . . . . . . . . . . . . . . . . . . .149
141.1 Requirements for Covered Processes in Additions, Alterations to Existing Nonresidential and Hotel/Motel Buildings. . . . . . . . . . . . . . . . . . . . . . . . .157
SUBCHAPTER 7 SINGLE-FAMILY RESIDENTIAL BUILDINGS—
MANDATORY FEATURES AND DEVICES. . . . . . . . . . . . . . . 159
150.0 Mandatory Features and Devices. . . . . . . . . . . . . . . .159
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CONTENTS
SUBCHAPTER 8 SINGLE-FAMILY RESIDENTIAL BUILDINGS—
PERFORMANCE AND PRESCRIPTIVE COMPLIANCE
APPROACHES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
150.1 Performance and Prescriptive Compliance Approaches for Single-Family Residential Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
SUBCHAPTER 9 SINGLE-FAMILY
RESIDENTIAL BUILDINGS—ADDITIONS AND ALTERATIONS
TO EXISTING RESIDENTIAL BUILDINGS . . . . . . . . . . . . . . 187
150.2 Energy Efficiency Standards for Additions and Alterations to Existing Single-Family Residential Buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
SUBCHAPTER 10 MULTIFAMILY BUILDINGS—MANDATORY
REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
§ 150.1 Medium relevance — show source text
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8 SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE
AND PRESCRIPTIVE COMPLIANCE APPROACHES
SECTION 150.1—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR SINGLE-FAMILY RESIDENTIAL BUILDINGS
(a) Basic requirements. Single-family residential buildings shall meet all of the following:
- The applicable requirements of Sections 110.0 through 110.10.
- The applicable requirements of Section 150.0 (mandatory features).
- Either the performance standards or the prescriptive standards set forth in this section for the climate zone in which the building is located. Climate zones are shown in Reference Joint Appendix JA2–Weather/Climate Data. Exception to Section 150.1(a)3: If a single contiguous subdivision or tract falls in more than one climate zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the climate zone that contains 50 percent or more of the dwelling units. Note: The Commission periodically updates, publishes, and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, as specified in Reference Joint Appendix JA2–Weather/Climate Data.
Note: The requirements of Sections 150.0(a) through 150.0(r) apply to newly constructed buildings and Sections 150.2(a) and 150.2(b) specifies changes to the requirements of Sections 150.1(a) through 150.1(c) that apply to additions or alterations.
(b) Performance approach. A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.
- Energy budget. The energy budget is expressed in terms of source energy and long-term system cost (LSC). A. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.
i. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, and the self-utilization credit.
ii. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), lighting, demand flexibility, and other plug loads. B. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building. The source energy is the total annual source energy. Exception to Section 150.1(b)1. A community shared solar electric generation system, or other renewable electric generation system, or community shared BESS, which provides dedicated power, utility energy reduction credits, or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system and demand flexibility Energy Design Rating required to comply with the Standards, as calculated according to methods established by the Commission in the Residential ACM Reference Manual.
§ 160.2 Medium relevance — show source text
iii. New dwelling units that are additions to an existing building shall have mechanical ventilation airflow provided in accordance with Section 160.2(b)2Aiv or 160.2(b)2Av as applicable. The mechanical ventilation airflow rate shall be based on the conditioned floor area of the new dwelling unit. B. Local mechanical exhaust . Additions to existing buildings shall comply with all applicable requirements specified in Sections 160.2(b)2Avi and 160.2(b)2B. 3. Water heater. When additional water-heating equipment is installed to serve a dwelling unit as part of the addition, one of the following types of water heaters shall be installed: A. A water-heating system that meets the requirements of Section 170.2(d); or B. A water-heating system determined by the Executive Director to use no more energy than the one specified in Item A above.
(b) Performance approach. Performance calculations shall meet the requirements of Sections 170.0 through 170.2(a), pursuant to the applicable requirements in Items 1, 2 and 3 below.
- For additions alone. The addition complies if the addition alone meets the energy budgets expressed in terms of long-term system cost (LSC) energy.
- Existing plus alteration plus addition. The standard design for existing plus alteration plus addition energy use is the combination of the existing building’s unaltered components to remain; existing building altered components that are the more efficient, in LSC energy, of either the existing conditions or the requirements of Section 180.2(c); plus the proposed addition’s energy use meeting the requirements of Section 180.1(a). The proposed design energy use is the combination of the existing building’s unaltered components to remain and the altered components’ energy features, plus the proposed energy features of the addition. Exception to Section 180.1(b)2: Existing structures with a minimum R-11 insulation in framed walls showing compliance with Section 180.1(b) are not required to show compliance with Section 160.1(b).
- Mechanical ventilation for indoor air quality . Additions to existing buildings shall comply with Section 160.2 subject to the requirements specified in Subsections A and B below. When field verification and diagnostic testing are required by Section 180.1(b)3, buildings with three habitable stories or fewer shall use the applicable procedures in the Residential Appendices, and buildings with four or more habitable stories shall use the applicable procedures in Nonresidential Appendices NA1 and NA2.
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A. Whole-dwelling unit mechanical ventilation . i. Dwelling units that meet the conditions in Subsection a or b below shall not be required to comply with the whole-dwelling unit ventilation airflow specified in Section 160.2(b)2Aiv or 160.2(b)2Av. a. Additions to an existing dwelling unit that increase the conditioned floor area of the existing dwelling unit by less than or equal to 1000 square feet. b. Junior accessory dwelling units (JADU) that are additions to an existing building. ii.
§ 1.88 Medium relevance — show source text
27|1.88|2.27|1.88|2.27|2.27|2.27|2.27|2.27|2.27|2.27|2.27|2.27|2.85|1.88| |1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|1. NR = Not Required.|
NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.8 and 25943, Public Resources Code .
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12 MULTIFAMILY BUILDINGS—ADDITIONS, ALTERATIONS
AND REPAIRS TO EXISTING MULTIFAMILY BUILDINGS
SECTION 180.0—GENERAL
Additions, alterations and repairs to existing attached dwelling units and common use areas in multifamily buildings, existing outdoor lighting for these occupancies, and internally and externally illuminated signs shall meet the requirements specified in Sections 100.0 through 110.10, 160.1, and 160.3 through 170.2 that are applicable to the building project, and either the performance compliance approach (energy budgets) in Section 180.1(b) (for additions) or 180.2(c) (for alterations), or the prescriptive compliance approach in Section 180.1(a) (for additions) or 180.2(b) (for alterations), for the climate zone in which the building is located. Climate zones are shown in Figure 100.1-A.
Covered process requirements for additions, alterations and repairs to existing multifamily buildings are specified in Section 141.1.
Nonresidential occupancies in mixed occupancy buildings shall comply with nonresidential requirements in Sections 120.0 through 141.1.
NOTE: For alterations that change the occupancy classification of the building, the requirements specified in Section 180.2 apply to the occupancy after the alterations.
NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
SECTION 180.1—ADDITIONS
§ 2.5. Medium relevance — show source text
ii. Temperature maintenance tank. Meet one of the following: A. The electrical power required to power a HPWH system temperature maintenance tank that meets the total building hot water demand as calculated and documented by the responsible person associated with the project. B. The electrical power required that meets the requirements specified for the temperature maintenance tank in Joint Appendix JA15.2.5.
NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
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11 MULTIFAMILY BUILDINGS—PERFORMANCE
AND PRESCRIPTIVE COMPLIANCE APPROACHES
SECTION 170.0—GENERAL
Multifamily buildings shall comply with the applicable requirements of Sections 170.0 through 170.2. Sections 170.0 through 170.2 apply to dwelling units and common use areas in multifamily buildings. Nonresidential occupancies in mixed occupancy buildings shall comply with nonresidential requirements in Sections 120, 130, 140 and 141.
(a) Multifamily buildings shall meet all of the following:
- The applicable requirements of Sections 110.0 through 110.10.
- The applicable requirements of Section 160.0 (mandatory features).
- Either the performance standards Section 170.1 or the prescriptive standards Section 170.2 set forth in this subchapter for the climate zone in which the building is located. Climate zones are shown in Reference Joint Appendix JA2— Weather/Climate Data.
Exception to Section 170.0 (a)3: If a single development falls in more than one climate zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the climate zone that contains 50 percent or more of the dwelling units.
NOTE: The Commission periodically updates, publishes and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, as specified in Reference Joint Appendix JA2—Weather/Climate Data.
NOTE: The requirements of Sections 170.1(a) through 170.2(e) apply to newly constructed buildings and Sections 180.1 and 180.2 specify changes to the requirements of Sections 170.1(a) through 170.2(e) that apply to additions or alterations.
NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .
SECTION 170.1—PERFORMANCE APPROACH
A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109 and 10-116 and the Alternative Calculation Method Reference Manual.
§ 150.0 Medium relevance — show source text
0, 150.0(k)|110.9, 130.0, 150.0(k)|110.9, 130.0, 150.0(k)|110.9, 130.0, 150.0(k)| |Single-family|Outdoor Lighting|110.9, 130.0, 150.0(k)|110.9, 130.0, 150.0(k)|110.9, 130.0, 150.0(k)|110.9, 130.0, 150.0(k)| |Single-family|Pool and Spa Systems|110.4, 150.0(p)|N.A.|N.A.|N.A.| |Single-family|Solar Ready Buildings|110.10|N.A.|N.A.|N.A.| |Single-family|Electric Ready|150.0(s), 150.0(t), 150.0(u),
150.0(v)|N.A.|N.A.|N.A.| |Single-family|Solar PV Systems|N.A.|150.0(c)14|150.1(a), (b)|N.A.| |Multifamily|General|160.0|170.2|170.1|180.0| |Multifamily|HVAC (conditioned)|110.6, 110.7, 110.8, 160.1|170.1(a)|170.1(a)|170.1(a)| |Multifamily|Ventilation and Indoor Air Quality|160.2|N.A.|N.A.|N.A.| |Multifamily|HVAC (conditioned)|110.2, 110.5, 160.3|170.2(c)|170.2(c)|170.2(c)| |Multifamily|Water Heating|110.3, 160.4|170.2(d)|170.2(d)|170.2(d)| |Multifamily|Indoor Lighting|110.9, 160.5|170.2(e)|170.2(e)|170.2(e)| |Multifamily|Outdoor Lighting|110.9, 160.5|170.2(e)|170.2(e)|170.2(e)| |Multifamily|Electrical Power Distribution|110.11, 160.6|N.A.|N.A.|N.A.| |Multifamily|Pool and Spa Systems|110.4, 110.5, 160.7|110.4, 110.5, 160.7|110.4, 110.5, 160.7|110.4, 110.5, 160.7| |Multifamily|Solar Ready Buildings|110.10, 160.8|110.10, 160.8|110.10, 160.8|110.10, 160.8| |Multifamily|Electric Ready|160.9|160.9|160.9|N.A.| |Multifamily|Solar PV and Battery Energy
Storage Systems|N.A.|170.2(f), (g), (h)|170.1|N.A.| |N.A. = Not Applicable
1.
Nonresidential and hotel/motel buildings that contain covered processes may conform to the applicable requirements of both occupancy types listed in this table.
Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1,Public Resources Code.§ 170.2 Medium relevance — show source text
The rated energy capacity shall be not less than the Minimum Rated Useable Energy Capacity determined by Equation 170.2-E, or by Equation 170.2-F if SARA was used to determine the PV capacity in Section 170.2-D, and the rated power capacity shall be not less than the Minimum Power Capacity determined by Equation 170.2-G. In mixed occupancy buildings, the total battery system capacity for the building shall be determined by applying the Minimum Rated Usable Energy Capacity to each of the listed building types and summing the capacities determined for each.
EQUATION 170.2-E—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY kWh batt = k((CFA × B)/(1000 × C [0.5] ))
— EQUATION 170.2-F BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY, SARA-ADJUSTED kWh batt = k((CFA × B)/(1000 × C [0.5] )) × (kWP Vdc,SARA /kWP Vdc )
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where:
kWh batt = Minimum Rated Usable Energy Capacity of the BESS in kWh.
kW PVdc = Minimum Rated PV System Capacity in kW from Equation 170.2D. kW PVdc, SARA = Minimum Rated PV System Capacity in kW from the SARA calculation. CFA = Conditioned floor area that is subject to the PV system requirements of Section 170.2(g) in square feet.
B = BESS Capacity Factor in Wh/square foot as specified in Table 170.2-V for the building type.
C = Rated single charge-discharge cycle AC to AC (round-trip) efficiency of the BESS.
EQUATION 170.2-G—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED POWER CAPACITY
kW batt = kW batt /4
where:
kW batt = Minimum Rated Power Capacity of the BESS in kW dc .
kWh batt = Minimum Rated Usable Energy Capacity of the BESS in kWh.
Exception 1 to Section 170.2(h): No BESS is required if the installed PV system capacity is less than 15 percent of the capacity determined by Equation 170.2-D.
Exception 2 to Section 170.2(h): No BESS is required in buildings with BESS requirements with less than 10 kWh minimum rated usable energy capacity.
|TABLE 170.
Frequently asked questions
How do I know whether to check LSC, Source Energy, or both?
For newly constructed buildings you must compare both LSC and Source Energy where the occupancy section requires them (nonresidential § 140.1, single‑family § 150.1, multifamily § 170.1). Additions/alterations are evaluated as LSC per § 100.2.
Where do the LSC hourly factors come from?
LSC hourly factors are published by the Energy Commission and summarized in Reference Joint Appendix JA3; the compliance software applies the hour‑by‑hour factors by climate zone and building type as described in § 100.2.
Can a community solar array count toward my building’s PV credit?
Yes — a community shared solar electric generation system or community BESS that is approved by the Energy Commission can offset required PV/BESS LSC energy under the exceptions in § 140.1, § 150.1, and § 170.1. Approval and calculation methods are specified by the Commission.
Does multifamily source energy treat gas water heaters differently?
Yes. § 170.1(a)2 specifies the source energy budget is determined by the standard design “except with a consumer gas or propane water heater,” so read § 170.1 carefully when consumer gas/propane water heating is part of the project.
What must I submit with a permit application for a multifamily project using the performance approach?
Section § 170.1(b)1–2 requires the Certificate of Compliance and documentation demonstrating with approved calculation methods that the design meets the source energy and LSC budgets; field verification requirements for unit systems are also specified.
More in California Energy Code
- Compliance paths, energy budgets, performance modeling and forms/software requirements
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- Envelope construction, insulation, fenestration and thermal performance
- HVAC systems, ventilation rates, ducting, controls and testing
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- Mandatory measures, appliance efficiency and certification requirements
- Photovoltaic requirements, BESS (battery energy storage) sizing and SARA procedures
- Reference appendices, test procedures, product certification and labeling requirements
- Scope, applicability, definitions and administrative requirements
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