Under California's Title 24 Energy Code, what is the maximum allowable fenestration area as a percentage of conditioned floor area for residential buildings in Climate Zone 1?
Correct Answer
D) 20%
Title 24 Part 6 Section 150.1(c) limits fenestration area to 20% of conditioned floor area in Climate Zone 1. This prescriptive requirement helps control heat gain in California's hottest climate zone and is part of the state's energy efficiency standards.
Why This Is the Correct Answer
Title 24 Part 6 Section 150.1(c) sets the prescriptive fenestration limit at 20% of conditioned floor area for Climate Zone 1 (California's hottest inland climate zone). This cap limits solar heat gain and reduces cooling loads in extreme heat conditions.
Why the Other Options Are Wrong
Option A: 25%
25% exceeds the allowable limit for Climate Zone 1. A higher fenestration ratio would allow excessive solar heat gain and would not satisfy the prescriptive compliance path; the designer would need to use the performance path instead.
Option B: 30%
30% is substantially above the 20% threshold and is not permitted under the prescriptive pathway for any standard residential Climate Zone 1 project. It is a plausible-sounding but incorrect distractor.
Option C: 15%
15% is more restrictive than required and is not the code-specified maximum. While a project could be designed with only 15% fenestration, that is not the maximum the code allows.
Memory Technique
Think '20 = Zone 1 + heat control': Climate Zone 1 is the hottest, so you keep windows at 20% — a tight budget to keep the heat out. Visualize a window that covers exactly one-fifth of your floor plan.
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