13.1 CALGreen (Title 24 Part 11) Mandatory Nonresidential & Residential Green Building Measures

CALGreen (Title 24 Part 11) Mandatory Nonresidential & Residential Green Building Measures

Codified in Title 24, Part 11 of the California Code of Regulations (CCR), the California Green Building Standards Code—universally known as CALGreen—is the first comprehensive, statewide mandatory green building code adopted in the United States. While Part 6 of Title 24 governs building energy efficiency, CALGreen addresses the broader ecological and human health impacts of the built environment. CALGreen regulates planning and site development, water conservation, resource efficiency, and indoor environmental air quality. For candidates preparing for the California Supplemental Examination (CSE), understanding the mandatory baseline provisions, recognizing the architectural thresholds for Electric Vehicle (EV) infrastructure, water reduction calculations, construction waste diversion, and low-emitting materials, and distinguishing statewide mandates from locally adopted voluntary reach tiers are critical for regulatory compliance and municipal plan check clearance.

Statutory Framework: Mandatory Measures vs. Voluntary Tiers

CALGreen is structured into two distinct regulatory tiers that architects must navigate during project scoping and design entitlement:

1. Mandatory Measures (Statewide Baseline)

The mandatory provisions of CALGreen apply automatically to all newly constructed buildings, tenant improvements, and qualifying additions or alterations throughout California. These provisions are organized into two parallel tracks:

• Chapter 4 (Residential): Covers low-rise and high-rise residential occupancies, including single-family dwellings, duplexes, townhouses, apartments, condominiums, hotels, motels, and residential care facilities.
• Chapter 5 (Nonresidential): Encompasses commercial, retail, educational, institutional, and industrial facilities, as well as common areas of mixed-use buildings. Compliance with mandatory measures is legally required to obtain a building permit and Certificate of Occupancy from the local Authority Having Jurisdiction (AHJ).

2. Voluntary Tiers (Tier 1 and Tier 2 Reach Codes)

Appendices A4 (Residential) and A5 (Nonresidential) contain voluntary performance standards designed for jurisdictions seeking to exceed the baseline code. Under California Health and Safety Code Sections 17958.5 and 17958.7, a local city or county may enact local "reach codes" by formally adopting Tier 1 or Tier 2 provisions based on local climatic, geological, or topographical findings filed with the California Building Standards Commission (CBSC):

• Tier 1: Requires full compliance with all mandatory measures plus elevated elective prerequisites, including enhanced EV infrastructure percentages, a 30% indoor water use reduction, and 75% construction waste diversion.
• Tier 2: Imposes the state's highest performance benchmarks, requiring a 35% to 40% indoor water reduction, 80% construction waste diversion, third-party post-construction indoor air testing, and advanced energy efficiency exceedances coordinated with Title 24 Part 6.

---

Division 5.1 & 4.1: Planning and Design

Site planning under CALGreen integrates multi-modal transportation, electric vehicle adoption, and nocturnal dark sky preservation:

Electric Vehicle (EV) Charging Infrastructure

California has pioneered the nation's most aggressive building code provisions for electric vehicles. CALGreen categorizes EV infrastructure into three progressive technical stages:

1. EV Capable: The building electrical panel must provide dedicated spare capacity (minimum 40-ampere, 208/240-volt branch circuit per space) with continuous raceways (conduits) routed from the main electrical service panel to an identified junction box terminating in the parking area.
2. EV Ready: Includes the complete raceway, dedicated branch circuit, wiring, and a 208/240-volt 40-ampere receptacle (or enclosed junction box) installed and energized at the parking space, ready for immediate charger plug-in.
3. EV Installed (EVSE): Full Electric Vehicle Supply Equipment (Level 2 charger or DC fast charger) is physically installed, wired, certified, and fully operational upon building delivery.

Scoping Thresholds: Under nonresidential Division 5.106.5.3, new commercial parking facilities must provide EV infrastructure based on total parking capacity. Progressive revisions require approximately 20% to 25% of total spaces to be EV Capable, 10% to 15% EV Ready, and 5% with operational EVSE installed. In multifamily residential construction (Division 4.106.4), 100% of dwelling units with dedicated parking must be provided with EV infrastructure (combining EV Capable, EV Ready, and operational EVSE).

Bicycle Parking

To support active transportation, nonresidential facilities must provide both short-term and long-term bicycle parking under Section 5.106.4:

• Short-Term Bicycle Parking (§ 5.106.4.1): For new buildings with visitor parking, permanently anchored bicycle racks must be provided within 200 feet of the primary visitor entrance, serving at least 5 percent of the total visitor vehicular parking capacity (minimum 2 bike spaces).
• Long-Term Bicycle Parking (§ 5.106.4.2): For nonresidential buildings with 10 or more tenant-occupant vehicular spaces, secure, covered bicycle parking must be provided for at least 5 percent of tenant vehicular capacity. Acceptable configurations include locked bicycle lockers, individual bike storage rooms, or fully enclosed, keycard-monitored interior parking enclosures.

Clean Air Vehicle Parking

Under Section 5.106.5.2, nonresidential parking facilities must designate preferred parking stalls for clean air vehicles (zero-emission vehicles, plug-in hybrids, and carpools/vanpools). Designated stalls must be located closest to the main building entrance (secondary only to accessible stalls) and marked with reflective pavement painting stating "CLEAN AIR / VANPOOL / EV" and permanent upright signs.

Light Pollution Reduction (BUG Ratings)

Exterior lighting must comply with Section 5.106.8 to minimize sky glow, reduce light trespass across property boundaries, and prevent glare. Luminaires with outputs exceeding 1,800 lumens must satisfy the Illuminating Engineering Society (IES) Backlight, Uplight, and Glare (BUG) ratings established in CALGreen Table 5.106.8, based on the designated California Lighting Zone (LZ1 through LZ4) under Title 24 Part 6.

---

Division 5.3 & 4.3: Water Efficiency and Conservation

California's arid climate and cyclical droughts make water conservation a central pillar of architectural design:

Indoor Potable Water Reduction (Mandatory 20% Reduction)

Under Sections 5.303.2 and 4.303.1, buildings must achieve a minimum 20 percent reduction in indoor potable water use compared to the baseline fixture consumption established by the California Plumbing Code (Title 24 Part 5). Architects demonstrate compliance through either the Performance Method (submitting a whole-building water budget calculation worksheet showing a 20% net reduction across all fixtures) or the Prescriptive Method by specifying fixtures that meet or exceed CALGreen maximum flow rates:

• Water Closets (Toilets): Maximum effective flush volume of 1.28 gallons per flush (gpf) (or dual-flush systems averaging ≤ 1.28 gpf).
• Urinals: Maximum flow rate of 0.125 gpf for wall-hung urinals (or waterless urinals).
• Nonresidential Public Lavatory Faucets: Maximum flow rate of 0.5 gallons per minute (gpm) at 60 psi (or metering faucets delivering ≤ 0.20 gallons per cycle).
• Residential Lavatory Faucets: Maximum flow rate of 1.2 gpm at 60 psi.
• Kitchen Faucets: Maximum flow rate of 1.8 gpm at 60 psi (temporary override up to 2.2 gpm is permitted for pot filling in commercial kitchens).
• Showerheads: Maximum flow rate of 1.8 gpm at 80 psi.

Outdoor Water Efficiency & MWELO Compliance

Under Sections 5.304 and 4.304, outdoor landscape designs must strictly comply with the California Model Water Efficient Landscape Ordinance (MWELO) codified in Title 23, California Code of Regulations, Chapter 2.7. MWELO applies to new landscape projects with an aggregate landscape area equal to or greater than 500 square feet (or rehabilitated landscapes ≥ 2,500 sq ft):

• Water Budget Calculation: The landscape architect or architect must calculate the Maximum Applied Water Allowance (MAWA) and demonstrate that the Estimated Total Water Use (ETWU) does not exceed the MAWA ceiling.
• Hydrozoning & Smart Controllers: Irrigation systems must be grouped into distinct hydrozones based on plant water needs and sun exposure, controlled by automated weather-based irrigation controllers (ET controllers) or soil moisture sensors that automatically suspend irrigation during rain events.
• Dedicated Landscape Meters: Dedicated water submeters must be provided for landscape areas exceeding 1,000 square feet in nonresidential projects to isolate irrigation consumption from domestic building water.

Nonresidential Water Submetering

Under Section 5.303.1, separate water submeters must be installed for individual leased tenant spaces within nonresidential buildings where commercial spaces consume more than 100 gallons per day or exceed 50,000 square feet, as well as dedicated submeters for cooling towers and commercial kitchens.

---

Division 5.4 & 4.4: Material Conservation and Resource Efficiency

Material conservation rules divert waste from landfills and mandate long-term building resource efficiency:

Construction and Demolition (C&D) Debris Diversion (Mandatory 65%)

Pursuant to Sections 5.408.1 and 4.408.1, all new construction, additions, and qualifying demolition projects must divert at least 65 percent of nonhazardous construction and demolition (C&D) debris away from landfills through recycling, reuse, or salvage:

• Construction Waste Management Plan (CWMP): Prior to building permit issuance, the architect or general contractor must submit a CWMP to the AHJ identifying the types of waste generated (concrete, drywall, lumber, metals, cardboard), designated recycling facilities, and whether materials will be source-separated on site or commingled.
• Documentation & Weigh Tickets: Prior to final building inspection and issuance of the Certificate of Occupancy, the contractor must submit certified weigh tickets and a final diversion report proving that the mandatory 65% threshold was achieved. If a local municipal ordinance enforces a stricter diversion target (e.g., 75% or 100%), the stricter local requirement governs.

Recycling and Organic Waste Storage

Under Section 5.410.1 and California Public Resources Code Section 42911 (AB 341), nonresidential buildings and multifamily residential developments must provide dedicated, readily accessible exterior or interior storage areas for the collection and loading of recyclable materials (paper, cardboard, glass, plastics, and metals). Furthermore, in compliance with Senate Bill 1383 (SB 1383), facilities must incorporate dedicated space for organic waste and compost collection bins.

---

Division 5.5 & 4.5: Environmental Quality (Indoor Air Quality)

CALGreen establishes stringent indoor air quality benchmarks to protect occupant health from hazardous off-gassing:

Low-Emitting Materials and VOC Limits

Architectural specifications must enforce strict volatile organic compound (VOC) limits across interior finishes:

• Architectural Paints and Coatings (§ 5.504.4.3): Must comply with VOC content limits established by the South Coast Air Quality Management District (SCAQMD) Rule 1113 or the California Air Resources Board (CARB) Suggested Control Measure (e.g., flat coatings ≤ 50 g/L; non-flat coatings ≤ 50 g/L; primers ≤ 100 g/L).
• Adhesives, Sealants, and Caulks (§ 5.504.4.1): Must satisfy SCAQMD Rule 1168 limits (e.g., dry wall and panel adhesives ≤ 50 g/L; ceramic tile adhesives ≤ 65 g/L; architectural sealants ≤ 250 g/L).
• Carpet Systems (§ 5.504.4.4): All carpet installed in the building interior must be certified under the Carpet and Rug Institute (CRI) Green Label Plus program.
• Resilient Flooring (§ 5.504.4.6): Vinyl composition tile (VCT), linoleum, rubber, and laminate flooring must be certified under FloorScore or meet the California Department of Public Health (CDPH) Standard Method v1.2.
• Composite Wood Products (§ 5.504.4.5): Hardwood plywood, particleboard, and medium-density fiberboard (MDF) installed in interior millwork, cabinetry, and structural framing must comply with the California Air Resources Board (CARB) Airborne Toxic Control Measure (ATCM), codified in Title 17 CCR Section 93120 (Phase 2 emission limits), or be certified as Ultra-Low-Emitting Formaldehyde (ULEF) or No-Added Formaldehyde (NAF).
• Thermal and Acoustical Insulation: Must not contain added formaldehyde and must meet CDPH Standard Method v1.2 VOC testing.

Building Flush-Out or Indoor Air Quality Testing

To eliminate residual VOCs and particulates prior to tenant occupancy, Section 5.504.4.5 requires the contractor to complete one of two procedures:

1. Building Flush-Out: Supply a cumulative minimum of 14,000 cubic feet of outdoor air per square foot of gross floor area while maintaining interior temperatures between 60°F and 80°F and relative humidity not exceeding 60%. Occupants cannot enter the space until the complete flush-out volume has been delivered.
2. Indoor Air Quality (IAQ) Testing: Conduct baseline air testing after construction completion but prior to occupancy. Air samples collected across representative breathing zones must demonstrate that contaminant concentrations do not exceed CALGreen Table 5.504.4.3 limits (e.g., Formaldehyde < 27 ppb; Total VOCs < 500 µg/m³; PM2.5 < 12 µg/m³; PM10 < 50 µg/m³; 4-Phenylcyclohexene < 3 µg/m³).

---

Table: CALGreen Mandatory Divisions, Scoping, and Threshold Requirements

---

CSE Exam Traps & Practical Takeaways

• Trap 1: Mandatory vs. Tier Reach Codes: Candidates frequently confuse statewide baseline mandates with Tier 1 and Tier 2. CALGreen Tiers are not mandatory statewide; they are model reach codes that become mandatory only if an individual municipality or county formally adopts them under Health and Safety Code § 17958.5.
• Trap 2: EV Capable vs. EV Ready vs. EVSE Installed: Exam questions test the precise differences between EV stages. Specifying conduit and panel breaker space satisfies "EV Capable," but does not satisfy "EV Ready" (which requires the actual energized branch circuit and 208/240V receptacle) or "EV Installed" (which requires the physical charger hardware).
• Trap 3: C&D Debris Verification Timing: A Construction Waste Management Plan (CWMP) is submitted before permit issuance, but compliance is not closed out until the contractor provides certified waste facility weigh tickets demonstrating ≥ 65% actual diversion prior to Certificate of Occupancy.
• Trap 4: Public Lavatory vs. Private Lavatory Flow Rates: Nonresidential public restrooms are capped at 0.5 gpm (or 0.20 gal/cycle for metering faucets). Specifying a standard residential faucet of 1.2 gpm in a commercial office lobby restroom violates CALGreen Section 5.303.2.