According to CALGreen (California Green Building Standards Code), what is the minimum water efficiency requirement for toilets in new residential construction?
Correct Answer
A) 1.28 gallons per flush or less
CALGreen Section 4.303.1 requires toilets to use no more than 1.28 gallons per flush in residential buildings. This exceeds federal standards and reflects California's commitment to water conservation, particularly important given the state's frequent drought conditions and water scarcity issues.
Why This Is the Correct Answer
CALGreen Section 4.303.1 mandates that toilets in new residential construction use no more than 1.28 gallons per flush (gpf). This is the High-Efficiency Toilet (HET) standard. California adopted this threshold to conserve water, exceeding the 1.6 gpf federal standard. The 1.28 gpf requirement aligns with WaterSense-labeled products.
Why the Other Options Are Wrong
Option B: 2.0 gallons per flush or less
2.0 gpf is above the federal standard (1.6 gpf) and well above CALGreen's 1.28 gpf requirement. No modern California code allows 2.0 gpf for new construction — this is a plausible-sounding distractor referencing older standards.
Option C: 1.0 gallons per flush or less
1.0 gpf (ultra-low flush / dual-flush average) is more stringent than CALGreen requires for standard toilets. While some ultra-high-efficiency toilets achieve this, it is not the mandated minimum threshold under Section 4.303.1.
Option D: 1.6 gallons per flush or less
1.6 gpf is the federal Energy Policy Act standard, but California's CALGreen goes further, requiring 1.28 gpf. Choosing 1.6 gpf reflects knowledge of federal law but not California's more aggressive water conservation code.
Memory Technique
CAL(Green) = 1.28. Think: California is 'ahead' of the federal 1.6 standard by about 20%. 1.28 is roughly 1.6 minus 20%. Or remember: HET = High Efficiency Toilet = 1.28 = CALGreen requirement.
More trade-general-building Questions
When installing engineered lumber joists (I-joists) in California residential construction, what is the primary code requirement for web stiffeners?
What is the required attic ventilation ratio when a vapor retarder is installed on the warm-in-winter side of the ceiling according to the California Residential Code?
In California's Wildland-Urban Interface (WUI) areas, which underlayment requirement applies to Class A fire-rated roof assemblies?
In California, when installing a tankless water heater in a seismic zone, what additional requirement must be met beyond standard installation practices?
According to the California Building Code (CBC), what is the minimum lap splice length for #4 rebar in a concrete foundation wall in normal weight concrete with f'c = 3000 psi?
According to CBC requirements for retaining walls in California, what additional design consideration must be addressed for retaining walls over 4 feet in height located in seismic design categories D, E, and F?
When constructing retaining walls in California that exceed 4 feet in height, which CBC requirement must be met regarding drainage?
Under California regulations, when is a reduced pressure principle (RPP) backflow prevention assembly required for a residential water service connection?
Under California Title 24, what is the minimum electrical service size required for new single-family residential construction?
According to the California Building Code, buildings located in Seismic Design Category D must comply with which specific seismic design requirements?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
When installing roof ventilation in California, what is the standard net free ventilating area ratio required when both intake and exhaust vents are provided?
Next Question
For a gable roof with a total roof area of 2,400 square feet in California, what is the minimum net free ventilation area required if using the 1:300 ventilation ratio with both intake and exhaust vents?