2023 California Energy Code Update for Single Family Buildings

The 2022 Title 24 Building Energy Efficiency Standards (Energy Code or Title 24) updates the currently-enforced 2019 Energy Code. The 2022 Energy Code will be effective as of January 1, 2023. Any projects that apply for a permit on or after this date will be subject to the 2022 Energy Code. This article highlights the key changes to the California Energy Code that will apply to single-family buildings.

Single Family Building, Defined
In the 2019 Energy Code, low-rise multifamily buildings (≤3-stories) were grouped in the same code sections as single-family buildings. In the 2022 Energy Code, single-family buildings will include single-family homes, accessory dwelling units (ADUs), duplexes and townhomes of any height. The update also reorganizes low-rise and high-rise multifamily buildings into one building type and moves requirements for multifamily buildings into their own (separate) subchapters.

Kitchen Range Hood Airflow: Mandatory Requirements
New airflow, controls and HERS verification requirements for kitchen range hoods become dependent upon the kitchen configuration (enclosed or non-enclosed), area of the dwelling unit (ft²) and whether a range is electric or natural gas. Non-enclosed kitchens must have demand-controlled ventilation; enclosed kitchens may have either demand-controlled or continuous ventilation.

Whole-house Unit Ventilation
Under the updated Code, Junior Accessory Dwelling Units (JADUs), classified as additions to existing buildings ≤500 ft², will no longer be required to meet the 2019 Energy Code’s whole-house ventilation requirements.

Federal Efficiency Requirements: Split System Heat Pump & Air-conditioning Units
Department of Energy (DOE) minimum efficiencies for central air conditioners and heat pumps will increase on January 1, 2023. HVAC manufacturers will also be required to comply with a new testing procedure and efficiency ratings for SEER2, EER2 and HSPF2. Minimum central heat pump efficiency ratings will change to HSPF2 and SEER2 based on when the equipment was manufactured. Minimum central air-conditioner efficiency ratings will change to SEER2 and EER2 based on when the equipment was installed.

Altered Duct Systems: Duct Sealing
The 2022 Energy Code will change the extended duct length triggering duct sealing from > 40’ to >25’. Additionally, extended ducts >25’ added to an existing system will have new HERS duct testing leakage rate requirements. HERS field verification and diagnostic testing must confirm that measured duct leakage is10% or less of system handler airflow or that measured duct leakage to the outside is 7% or less of system handler airflow. In the 2019 Energy Code, the maximum leakage rates were 15% and 10%, respectively. When any length of ductwork is extended from an existing duct system to serve an addition, the entire duct system must be sealed and tested to meet the same requirements above.

CA Climate Zone Map

Heating System Type: Prescriptive Requirements
For new construction heating systems in Climate Zones 3, 4, 13 and 14, heat pump space heating is required. A gas furnace may be used prescriptively in all other Climate Zones.

Domestic Water-heating Systems: Prescriptive Requirements
In new construction, domestic water-heating system must meet the performance requirements of Section 150.1(b)1 or the water-heating system must meet one of the following prescriptive requirements:
• A single 240-volt heat pump water heater (HPWH) with a storage tank in the garage or conditioned space.
• A single 240-volt HPWH meeting the requirements of NEEA Advanced Water Heater Specification Tier 3 or higher with a storage tank in the garage or conditioned space.
• A solar water-heating system with electric backup and a minimum 70% solar savings fraction (SSF). Exceptions:
• Single-family buildings in Climate Zones 3, 4, 13 and 14 may use gas or propane tankless water heaters if the space-conditioning system is a heat pump that complies with Section 150.1(c)6.
• New dwelling units ≤ 500 ft2 conditioned floor area (CFA) with point-of-use distribution may use an instantaneous electric water heater.
• New dwelling units with 1 bedroom or less may use a 120-volt HPWH.

Photovoltaic System Requirements
Prescriptive requirements for photovoltaic (PV) systems do not apply if the minimum system size specified by the Energy Code is less than 1.8 kW. In single-family buildings, PV, battery storage, and electric- and solar-ready requirements apply only to new construction.

Energy Storage Systems (ESS) Ready
New homes have will now have mandatory requirements for being ready for future installation of battery storage systems, also called energy storage systems (ESS). In all new single-family residences that include one or two dwelling units, one of the following is required:
1. Either:
• ESS-ready interconnection equipment with a minimum backed up capacity of 60 amps and a minimum of four ESS-supplied branch circuits.
• Four or more branch circuits from a single panelboard suitable to be supplied by the ESS: At least one circuit must supply the refrigerator, lighting circuit near the primary egress, and a sleeping room receptacle outlet.
2. A main panelboard with a minimum busbar rating of 225 amps.
3. Sufficient space reserved to allow future installation of system isolation equipment or a transfer switch within 3 ft of the main panelboard.

Electric Ready
New homes will have mandatory requirements for being ready to install electric heat pump space heaters, electric cooktops and electric clothes dryers (see table below).

Additions and Alterations: Altered Ceiling Insulation
In Climate Zones 1-4, 6, and 8-16, ceiling alterations to vented attics must have an overall weighted U-factor of maximum 0.20 or R-49 insulation at the ceiling. However, in Climate Zones 1, 3 and 6, ceiling alterations do not need to meet this requirement if there is existing R-19 or more insulation at the ceiling. A project may have additional requirements to meet, based on its Climate Zone. In climate zones 1-4 and 8-16 the requirement will be to: 1). cover recessed downlight luminaires in the ceiling with insulation to the same depth as the rest of the ceiling and, 2). replace or retrofit luminaires not rated for insulation-contact with a fire-proof cover that allows for insulation to be installed directly over the cover.

Additions and Alterations: Re-roofing Products and Insulation
When more than 50% of a roof is being replaced, the prescriptive requirement is that products used to reroof the building must meet minimum requirements for aged solar reflection and thermal emittance or meet solar reflectance index (SRI) requirements. In addition to meeting these roofing product requirements, the 2022 Energy Code now also requires that low-sloped roofs have insulation above or below the roof deck. In Climate Zones 1, 2, 4 and 8-16, one of the following is required:
• R-14 continuous insulation above the roof deck.
• Overall assembly U-factor ≤ 0.039 (i.e. minimum R-11 cavity insulation below the roof deck).

Roof Deck, Ceiling and Rafter Roof Insulation
This is a new mandatory requirement that applies to new construction and additions over 700 ft². New mandatory U-factor requirements apply to the roof deck of new attics, in addition to the Mandatory ceiling insulation requirements already in place. In Climate Zones 4 and 8-16, if the air handler and ducts are located anywhere outside of the conditioned space, the roof deck separating attic spaces from ambient air must meet an area weighted U-factor of 0.184 or less This may be achieved by installing R-4 continuous insulation or greater above the roof deck, or R-3 cavity insulation below the roof deck. There are two exceptions to installing mandatory roof deck insulation. It is not required if a project uses either ducts in conditioned space (DCS) or less than 12 linear feet of supply duct in unconditioned space. Both exceptions would require HERS verification.

For Further Reading:
• Information and documents are available at: https://www.energy.ca.gov/programs-and-topics/programs/building-energy-efficiency-standards/2022-building-energy-efficiency

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