CRC Building Codes & Regulations 2 — Questions and Answers
Question 1: Under the International Residential Code (IRC), what is the minimum ceiling height required for habitable rooms?
- 7 feet 0 inches (Correct answer)
- 7 feet 6 inches
- 8 feet 0 inches
- 6 feet 8 inches
Correct answer: 7 feet 0 inches
The IRC requires a minimum ceiling height of 7 feet 0 inches for habitable rooms.
Question 2: Which document serves as the basis for most residential building codes adopted across the United States?
- National Building Code (NBC)
- International Residential Code (IRC) (Correct answer)
- Uniform Building Code (UBC)
- Standard Building Code (SBC)
Correct answer: International Residential Code (IRC)
The IRC, published by the International Code Council (ICC), is the model code most widely adopted by states and municipalities for one- and two-family dwellings.
Question 3: A residential contractor is building a deck that is 30 inches above grade. Under the IRC, is a guardrail required?
- No, guardrails are only required above 36 inches
- Yes, guardrails are required at 30 inches or more above grade (Correct answer)
- No, guardrails are only required above 48 inches
- Yes, but only if the deck is attached to the house
Correct answer: Yes, guardrails are required at 30 inches or more above grade
The IRC requires guardrails on decks and elevated surfaces 30 inches or more above the grade below.
Question 4: What is the purpose of a Certificate of Occupancy (CO)?
- It authorizes the contractor to begin construction
- It confirms the building meets code and is safe to occupy (Correct answer)
- It transfers property ownership to the buyer
- It grants a variance from a zoning requirement
Correct answer: It confirms the building meets code and is safe to occupy
A Certificate of Occupancy is issued by the local authority having jurisdiction to confirm a structure complies with applicable codes and is safe for use.
Question 5: Under the IRC, what is the maximum rise (height) allowed for a single stair riser in a residential application?
- 7 inches
- 7¾ inches (Correct answer)
- 8½ inches
- 8 inches
Correct answer: 7¾ inches
The IRC limits stair riser height to a maximum of 7¾ inches for residential construction.
Question 6: When is a building permit NOT typically required for residential work?
- Replacing a load-bearing wall
- Installing a new electrical panel
- Painting, wallpapering, or similar finish work (Correct answer)
- Adding a new bathroom
Correct answer: Painting, wallpapering, or similar finish work
Cosmetic work such as painting, wallpapering, and flooring typically does not require a building permit, unlike structural or mechanical work.
Question 7: Under the IRC, what is the minimum width required for a residential exit door (egress door)?
- 32 inches clear (Correct answer)
- 34 inches clear
- 36 inches nominal
- 32 inches nominal
Correct answer: 32 inches clear
The IRC requires a minimum clear width of 32 inches for the required egress door of a dwelling unit.
CRC Building Codes & Regulations 2
Under the International Residential Code (IRC), what is the minimum ceiling height required for habitable rooms?