Carlsbad Municipal Code Ch. 18.30 California Energy Code

A. The 2025 California Energy Code, California Code of Regulations, Title 24, a portion of the California Building Standards Code, is adopted in its entirety and incorporated by this reference as the energy code except for changes, additions, deletions and amendments in this chapter. The following appendices of the energy code are included in the adoption: Appendix 1-A (Standards and Documents Referenced). The following appendices are deleted: Appendix 1-B.

B. The building official is hereby authorized and directed to apply the administrative, organizational and enforcement rules and regulations of the city's building code, as amended, to implement the energy code or portions of the code adopted. Administrative provisions relating to duties and powers of the authority having jurisdiction, permits, fees, certificates of occupancy, service utilities, stop work orders, violations, penalties, and appeals are specified in Sections 103 through 105, and 107 through 116 of the California Building Code, Part 2, Volume 1, Chapter 1-Division II, as amended and adopted by the city.

(Ord. CS-437 § 13, 2022; Ord. CS-498, 12/2/2025)

Section 120.11 is added to read as follows:

120.11 Solar or recovered energy requirements for service water heating systems.

Any newly constructed nonresidential building shall derive its service water heating from a system that provides at least 40 percent of the energy needed for service water heating from on-site solar energy or recovered energy. Solar energy includes solar photovoltaics and solar-water heating systems.

Exception to Section 120.11: Buildings for which the building official has determined that service water heating from on-site solar energy or recovered energy is economically or physically infeasible. Applicant is responsible for demonstrating requirement infeasibility when applying for an exemption.

(Ord. CS-437 § 13, 2022)

Section 140.5 is amended to read as follows:

140.5 Prescriptive requirements for service water—heating systems.

A. Nonresidential occupancies. Service water-heating systems in nonresidential buildings and structures shall meet the requirements of 1 or 2 below, or meet the performance compliance requirements of Section 140.1:

1. School buildings less than 25,000 square feet and less than 4 stories in Climate Zones 2 through 15. A heat pump water-heating system that meets the applicable requirements of Sections 110.1, 110.3, 120.3, 120.11 and 140.5(c).

2. All other occupancies. A service water-heating system that meets the applicable requirements of Sections 110.1, 110.3, 120.3, 120.11 and 140.5(c). In addition, a service water-heating system installed in a nonresidential building or structure shall meet the requirements of parts A, B, or C below:

a. A heat pump water heater. The storage tank shall be located in a conditioned space.

b. An electric resistance water heater.

c. A solar water-heating system with a minimum solar savings fraction of 0.40. Solar water-heating systems and collectors shall be certified and rated by the Solar Rating and Certification Corporation (SRCC), the International Association of Plumbing and Mechanical Officials, Research and Testing (IAPMO R&T), or by a listing agency that is approved by the Executive Director.

B. Hotel/motel occupancies. A service water-heating system installed in hotel/motel buildings and structures shall meet the requirements of Section 170.2(d) and Section 140.5(c) and be located in the garage or conditioned space.

C. High-capacity service water-heating systems. Gas service water-heating systems with a total installed gas water heating input capacity of 1 MMBtu/h or greater shall have gas service waterheating equipment with a minimum thermal efficiency of 90 percent. Multiple units can meet this requirement if the water-heating input provided by equipment with thermal efficiencies above and below 90 percent averages out to an input capacity-weighted average of at least 90 percent.

Exception 1 to Section 140.5(c): If 25 percent of the annual service water-heating requirement is provided by site-solar energy or site-recovered energy.

Exception 2 to Section 140.5(c): Water heaters installed in individual dwelling units.

Exception 3 to Section 140.5(c): Individual gas water heaters with input capacity at or below 100,000 Btu/h shall not be included in the calculations of the total system input or total system efficiency.

(Ord. CS-437 § 13, 2022)

A. Section 141.2 is added to read as follows:

141.2 Additions, alterations and repairs—nonresidential photovoltaic system required.

Additions to existing nonresidential and hotel/motel buildings where the total roof area is increased by at least 2,000 square feet, and alterations to existing nonresidential and hotel/motel buildings with a permit valuation of at least $1,000,000 that affect at least 75 percent of the gross floor area shall also comply with the requirements of Section 141.2.1 or 141.2.2.

The required installation of a photovoltaic (PV) system shall be sized according to one of the following methods:

1. Based on gross floor area.

a. Buildings with greater than or equal to 10,000 square feet of gross floor area shall install a minimum PV system sized at 15 kilowatts direct current (kWdc) per 10,000 square feet of gross floor area.

PV system size = 15 kWdc X Building Size Factor, where the Building Size Factor (BSF) shall equal gross floor area / 10,000 sq. ft., rounded to the nearest tenth. The resulting product shall then be rounded to the nearest whole number. For example, a 126,800 square foot building shall require a minimum 191 kilowatt (kWdc) PV system, as follows:

PV system size = 15 kWdc X BSF, where BSF = 126,800 s.f. / 10,000 s.f. => 12.7 (rounded) 15 kWdc X 12.7 => 191 kWdc (rounded))

b. Buildings under 10,000 square feet of gross floor area shall install a minimum 5 kilowatt (kWdc) PV system. Applicants are encouraged to right-size the PV system based on the building's electrical demand to improve the system's cost effectiveness.

2. Based on Time Dependent Valuation (TDV). Install a solar PV system that will offset 80 percent of the building's TDV energy on an annual basis. The system sizing requirement shall be based upon total building TDV energy use including both conditioned and unconditioned space and calculated using modeling software or other methods approved by the building official.

Exceptions:

a. The building official may waive or reduce, by the maximum extent necessary, the provisions of this Section if the building official determines there are sufficient practical challenges to make satisfaction of the requirements infeasible. Practical challenges may be a result of the building site location, limited rooftop availability, or shading from nearby structures, topography, or vegetation. The applicant is responsible for demonstrating requirement infeasibility when applying for an exemption.

b. The building official may waive or reduce, by the maximum extent necessary, the provisions of this Section if the building official determines the building has satisfied the purpose and intent of this provision through the use of alternate on-site renewable generation systems such as wind energy systems.

(Ord. CS-437 § 13, 2022)

Section 150(n)5 is added to read as follows:

150(n)5 Solar or recovered energy requirements for service water heating systems.

Any newly constructed residential building shall derive its service water heating from a system that provides at least 60 percent of the energy needed for service water heating from on-site solar energy or recovered energy. Solar energy includes solar photovoltaics and solar-water heating systems.

Exception to Section 150(n)5: Buildings for which the building official has determined that service water heating from on-site solar energy or recovered energy is economically or physically infeasible. Applicant is responsible for demonstrating requirement infeasibility when applying for an exemption.

(Ord. CS-437 § 13, 2022)

Section 150.2(d) is added to read as follows:

150.2(d) Additions and alterations — energy efficiency required.

All additions and alterations of residential buildings with a building permit valuation of $60,000 or higher shall include one of the following energy efficiency measures:

A. Additions and alterations of single-family residential buildings built before 1978 shall include one of the following:

1. Duct sealing pursuant to the 2025 California Code of Regulations, Title 24, Section 150.2(b)1E without verification by a Home Energy Rating System (HERS) rater. All exceptions as stated in the 2025 California Code of Regulations, Title 24, Section 150.2(b)1E are allowed. Projects that require duct sealing as part of an HVAC alteration or replacement must meet all of the requirements of the 2025 California Code of Regulations, Title 24, Part 6, including HERS rater verification.

2. Attic insulation with a minimum of R-38 rating. Buildings without vented attic spaces and buildings with existing attic insulation levels greater than R-5 are exempt from this attic insulation energy efficiency measure.

3. Cool roof with an aged solar reflectance of greater than or equal to 0.25 and a thermal emittance of greater than or equal to 0.75. All exceptions as stated in the 2025 California Code of Regulations, Title 24, Section 150.2(b)1Ii for steep slope roofs and 150.2(b)1Iii for low slope roofs are allowed. Only areas of roof that are to be re-roofed are subject to the cool roof upgrade. Projects that are not installing a new roof as part of the scope are exempt from this cool roof energy efficiency measure.

B. Additions and alterations of single-family residential buildings built in 1978 or after shall include one of the following:

1. A lighting package consisting of:

a. Replacement of all interior and exterior screw-in (A-base) incandescent and halogen lamps with screw-in LED lamps; and

b. Installation of manual-on automatic-off vacancy sensors that meet the 2025 California Code of Regulations, Title 24, Section 110.9(b)4 in all bathrooms, bedrooms, offices, laundry rooms, utility rooms, and garages. Spaces which already include vacancy sensors, motions sensors, or dimmers do not need to install new sensors as required by the 2025 California Code of Regulations, Title 24, Section 110.9(b)4.

2. A water heating package consisting of:

a. Addition of exterior insulation meeting a minimum of R-6 to storage water heaters 20 gallons or larger in size, except if insulation installation would void the water heater warranty; and

b. Insulation of all accessible hot water pipes with pipe insulation a minimum of 0.75 inches in thickness. This includes insulating the supply pipe leaving the water heater, piping to faucets underneath sinks, and accessible pipes in attic spaces and crawlspaces; and

c. Upgrading of fitting in sinks and showers to meet current CALGreen (Title 24, Part 11 of the California Building Code) standards, except for fixtures with rated flow rates no more than 10 percent greater than current CALGreen standards.

C. Additions and alterations of multi-family residential buildings built before 1978 shall include attic insulation with a minimum of R-38 rating. Buildings without vented attic spaces and buildings with existing attic insulation levels greater than R-5 are exempt from this attic insulation energy efficiency measure.

D. Additions and alterations of multi-family residential buildings built between 1978 and 1991 shall include one of the following:

1. Duct sealing pursuant to the 2025 California Code of Regulations, Title 24, Section 150.2(b)1E without verification by a HERS rater. All exceptions as stated in the 2025 California Code of Regulations, Title 24, Section 150.2(b)1E are allowed. Projects that require duct sealing as part of an HVAC alteration or replacement must meet all of the requirements of the 2025 California Code of Regulations, Title 24, Part 6, including HERS rater verification.

2. Attic insulation with a minimum of R-38 rating. Buildings without vented attic spaces and buildings with existing attic insulation levels greater than R-5 are exempt from this attic insulation energy efficiency measure.

3. Cool roof with an aged solar reflectance of greater than or equal to 0.25 and a thermal emittance of greater than or equal to 0.75. All exceptions as stated in the 2025 California Code of Regulations, Title 24, Section 150.2(b)1Ii for steep slope roofs and Section 150.2(b)1Iii for low slope roofs are allowed. Only areas of roof that are to be re-roofed are subject to the cool roof upgrade. Projects that are not installing a new roof as part of the scope are exempt from this cool roof energy efficiency measure.

E. Additions and alterations of multi-family residential buildings built after 1991 shall include one of the following:

1. A lighting package consisting of:

a. Replacement of all interior and exterior screw-in (A-base) incandescent and halogen lamps with screw-in LED lamps; and

b. Installation of manual-on automatic-off vacancy sensors that meet the 2025 California Code of Regulations, Title 24, Section 110.9(b)4 in all bathrooms, bedrooms, offices, laundry rooms, utility rooms, and garages. Spaces which already include vacancy sensors, motions sensors, or dimmers do not need to install new sensors as required by the 2025 California Code of Regulations, Title 24, Section 110.9(b)4.

2. A water heating package consisting of:

a. Addition of exterior insulation meeting a minimum of R-6 to storage water heaters 20 gallons are larger in size, except for buildings with central water heating systems or if insulation installation would void the water heater warranty; and

b. Insulation of all accessible hot water pipes with pipe insulation a minimum of 0.75 inches in thickness. This includes insulating the supply pipe leaving the water heater, piping to faucets underneath sinks, and accessible pipes in attic spaces and crawlspaces; and

c. Upgrading of fittings in sinks and showers to meet current CALGreen standards, except for fixtures with rated flow rates no more than ten percent

Note: To the extent the provisions of 2025 California Code of Regulations, Title 24, Section 150.2(d) conflict with other provisions of the California Energy Code, then the most energy conserving provisions shall supersede and control.

Exception to 2025 California Code of Regulations, Title 24, Section 150.2(d): The requirement for inclusion of energy efficiency measures does not apply to residential buildings that receive a rating of seven or higher on the U.S. Department of Energy's Home Energy Score rating system based upon an assessment by a Home Energy Score Certified Assessor, to the satisfaction of the building official.

(Ord. CS-437 § 13, 2022; Ord. CS-498, 12/2/2025)

Section 180.5 is added to read as follows:

180.5 Additions, alterations and repairs—residential photovoltaic system required.

All additions, alterations and repairs multifamily residential buildings and structures with a permit valuation of $1,000,000 that affects at least 75 percent of the gross floor area shall comply with the requirements of 2025 California Code of Regulations, Title 24, Section 141.2 for the requirements applicable to the building and structures of this code.

(Ord. CS-437 § 13, 2022; Ord. CS-498, 12/2/2025)