10 free, exam-style R3 (R3) practice questions with answers and explanations. No signup required. Work through them below, then take the full free R3 practice test to study every exam domain.
A plans examiner is reviewing a second-floor bedroom that relies on a single window for its emergency escape and rescue opening (EERO). The window is well above grade. What is the minimum net clear opening area the window must provide?
Correct answer: A - 5.7 square feet
While checking a stair detail on a set of residential plans, the examiner needs to confirm the riser height complies with the IRC. What is the maximum riser height permitted for the stairway?
Correct answer: C - 7-3/4 inches
A plan shows a bonus room (a habitable space) built directly above an attached garage. To satisfy the dwelling-garage separation, what must be applied to the garage ceiling beneath that habitable room?
Correct answer: D - Not less than 5/8-inch Type X gypsum board
A habitable bedroom has a floor area of 150 square feet. Using natural light and natural ventilation (no mechanical system), what are the minimum required glazing area and minimum required openable area, respectively?
Correct answer: A - 12 sq ft glazing and 6 sq ft openable
On a site plan for a dwelling without an automatic sprinkler system, an exterior wall is located 3 feet from the property line. Per the IRC exterior wall provisions, this wall must be:
Correct answer: B - 1-hour fire-resistance rated
A foundation detail calls for 1/2-inch-diameter anchor bolts securing the sill plate to the concrete. Which spacing requirement does the IRC prescribe for these bolts?
Correct answer: C - Spaced not more than 6 feet on center
An open-riser stairway is proposed on a residential plan. To comply with the IRC, the opening between the treads must be sized so that it will not allow the passage of a sphere of what diameter?
Correct answer: D - 4 inches
An electrical plan shows the 120-volt, 20-amp receptacle circuits for an attached garage. Which protection does the IRC require for these garage receptacles?
Correct answer: A - GFCI protection
A plumbing plan is being reviewed for fixture traps. Excluding interceptors and fixtures with deeper integral traps, what liquid seal depth does the IRC permit for a fixture trap?
Correct answer: B - Not less than 2 inches and not more than 4 inches
A single-story dwelling has an attached garage but contains no fuel-fired appliances anywhere in the home. Regarding carbon monoxide alarms, the plans examiner should require that:
Correct answer: A - Carbon monoxide alarms are required because the dwelling has an attached garage
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