1 | Page
ICC 93 TALL MASS TIMBER BUILDINGS —
PRACTICE QUESTIONS WITH VERIFIED
ANSWERS AND COMPLETE RATIONALES
## SECTION 1: CONSTRUCTION TYPES &
CLASSIFICATIONS
**1. The 2021 IBC introduced which three new construction
types to accommodate tall mass timber buildings?**
A. Type III-A, III-B, III-C
B. Type IV-A, IV-B, IV-C
C. Type V-A, V-B, V-C
D. Type II-A, II-B, II-C
**Correct answer:** B
**Rationale:** The 2021 IBC added **Type IV-A, IV-B, and IV-
C** as new mass timber construction classifications alongside
the existing Type IV-HT (Heavy Timber). These new types
establish different levels of fire-resistance ratings,
encapsulation requirements, and allowable heights, enabling
taller wood buildings than previously permitted .
,2 | Page
--
**2. Which Type IV classification permits the greatest building
height for mass timber structures?**
A. Type IV-HT (Heavy Timber)
B. Type IV-A
C. Type IV-B
D. Type IV-C
**Correct answer:** B
**Rationale:** **Type IV-A** permits the highest building height,
allowing structures up to **270 feet (approximately 18
stories)**. Type IV-B allows 180 feet (12 stories), and Type IV-C
and Type IV-HT allow 85 feet .
--
**3. What is the maximum building height in feet for a building
of Type IV-B construction under the 2021 IBC?**
A. 85 feet
B. 120 feet
C. 180 feet
, 3 | Page
D. 270 feet
**Correct answer:** C
**Rationale:** Type IV-B construction is permitted up to **180
feet** in height (approximately 12 stories). This is the mid-range
option for mass timber buildings, balancing height allowance
with reduced encapsulation requirements compared to Type IV-
A.
--
**4. What is the maximum building height in feet for Type IV-C
construction?**
A. 85 feet
B. 120 feet
C. 180 feet
D. 270 feet
**Correct answer:** A
**Rationale:** IBC Section 602.4 explicitly limits Type IV-C
construction to **85 feet** in building height, although it permits
full timber exposure. This is the lowest height tier among the
new mass timber construction types .
ICC 93 TALL MASS TIMBER BUILDINGS —
PRACTICE QUESTIONS WITH VERIFIED
ANSWERS AND COMPLETE RATIONALES
## SECTION 1: CONSTRUCTION TYPES &
CLASSIFICATIONS
**1. The 2021 IBC introduced which three new construction
types to accommodate tall mass timber buildings?**
A. Type III-A, III-B, III-C
B. Type IV-A, IV-B, IV-C
C. Type V-A, V-B, V-C
D. Type II-A, II-B, II-C
**Correct answer:** B
**Rationale:** The 2021 IBC added **Type IV-A, IV-B, and IV-
C** as new mass timber construction classifications alongside
the existing Type IV-HT (Heavy Timber). These new types
establish different levels of fire-resistance ratings,
encapsulation requirements, and allowable heights, enabling
taller wood buildings than previously permitted .
,2 | Page
--
**2. Which Type IV classification permits the greatest building
height for mass timber structures?**
A. Type IV-HT (Heavy Timber)
B. Type IV-A
C. Type IV-B
D. Type IV-C
**Correct answer:** B
**Rationale:** **Type IV-A** permits the highest building height,
allowing structures up to **270 feet (approximately 18
stories)**. Type IV-B allows 180 feet (12 stories), and Type IV-C
and Type IV-HT allow 85 feet .
--
**3. What is the maximum building height in feet for a building
of Type IV-B construction under the 2021 IBC?**
A. 85 feet
B. 120 feet
C. 180 feet
, 3 | Page
D. 270 feet
**Correct answer:** C
**Rationale:** Type IV-B construction is permitted up to **180
feet** in height (approximately 12 stories). This is the mid-range
option for mass timber buildings, balancing height allowance
with reduced encapsulation requirements compared to Type IV-
A.
--
**4. What is the maximum building height in feet for Type IV-C
construction?**
A. 85 feet
B. 120 feet
C. 180 feet
D. 270 feet
**Correct answer:** A
**Rationale:** IBC Section 602.4 explicitly limits Type IV-C
construction to **85 feet** in building height, although it permits
full timber exposure. This is the lowest height tier among the
new mass timber construction types .
