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.
These 10 free R3 questions are organized by exam domain, so you can see how each part of the R3 blueprint is tested. Reveal the answer and explanation under each question.
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 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
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
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
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
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
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
The R3 exam also covers these domains. Drill them in the full free practice test:
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