Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 7 - Fire and Smoke Protection Features › Section 705 - EXTERIOR WALLS › Subsection 705.8 - Openings

Current through Register 1525, July 5, 2024
Openings in
exterior walls
shall comply
				  with Sections 705.8.1 through 705.8.6.
TABLE 705.8 MAXIMUM AREA OF EXTERIOR WALL OPENINGS
				  BASED ON FIRE SEPARATION DISTANCE AND DEGREE OF OPENING
				  PROTECTION
FIRE SEPARATION DISTANCE (feet)
DEGREE OF OPENING PROTECTION
ALLOWABLE
							 AREAa
0 to less than
							 3b,c
Unprotected, Nonsprinklered (UP, NS)
Not Permitted
Unprotected, Sprinklered (UP, S)i
Not Permitted
Protected (P)
Not Permitted
3 to less than 5d, e
Unprotected, Nonsprinklered (UP, NS)
Not Permitted
Unprotected, Sprinklered (UP, S)i
15%
Protected (P)
15%
5 to less than 10e, f
Unprotected, Nonsprinklered (UP, NS)
10%h
Unprotected, Sprinklered (UP, S)i
25%
Protected (P)
25%
10 to less than 15e, f,
							 g
Unprotected, Nonsprinklered (UP, NS)
15%h
Unprotected, Sprinklered (UP, S)i
45%
Protected (P)
45%
15 to less than 20f, g
Unprotected, Nonsprinklered (UP, NS)
25%
Unprotected, Sprinklered (UP,
							 S)i
75%
Protected (P)
75%
20 to less than 25f, g
Unprotected, Nonsprinklered (UP, NS)
45%
Unprotected, Sprinklered (UP, S)i
No Limit
Protected (P)
No Limit
25 to less than 30f,
							 g
Unprotected, Nonsprinklered (UP, NS)
70%
Unprotected, Sprinklered (UP,
							 S)i
No Limit
Protected (P)
No Limit
30 or greater
Unprotected, Nonsprinklered (UP, NS)
No Limit
Unprotected, Sprinklered (UP, S)i
Not Required
Protected (P)
Not Required
For SI: 1 foot = 304.8 mm.
UP, NS = Unprotected openings in buildings not equipped
							 throughout with an automatic sprinkler system in accordance with Section
							 903.3.1.1.
UP, S = Unprotected openings in buildings equipped
							 throughout with an automatic sprinkler system in accordance with Section
							 903.3.1.1.
P = Openings protected with an opening protective
							 assembly in accordance with Section 705.8.2.
a. Values indicated are the percentage of the area of
							 the exterior wall, per story.
b. For the requirements for fire walls of buildings
							 with differing heights, see Section 706.6.1.
c. For openings in a fire wall for buildings on the
							 same lot, see Section 706.8.
d. The maximum percentage of unprotected and protected
							 openings shall be 25 percent for Group R-3 occupancies.
e. Unprotected openings shall not be permitted for
							 openings with a fire separation distance of less than 15 feet for Group H-2 and
							 H-3 occupancies.
f. The area of unprotected and protected openings shall
							 not be limited for Group R-3 occupancies, with a fire separation distance of 5
							 feet or greater.
g. The area of openings in an open parking structure
							 with a fire separation distance of 10 feet or greater shall not be
							 limited.
h. Includes buildings accessory to Group R-3.
i. Not applicable to Group H-1, H-2 and H-3
							 occupancies.
705.8.1
Allowable area of openings.
The maximum area of unprotected and
				protected openings permitted in an
exterior wall
in any
story
of a building shall not exceed the percentages specified
				in Table 705.8.
Exceptions:
1. In other than Group H occupancies,
				unlimited unprotected openings are permitted in the first
story
above grade either:
1.1. Where the wall faces a street and has a
fire separation distance
of more than 15 feet (4572 mm);
				or
1.2. Where the wall faces an
				unoccupied space. The unoccupied space shall be on the same lot or dedicated
				for public use, shall not be less than 30 feet (9144 mm) in width and shall
				have access from a street by a posted fire lane in accordance with the
International Fire Code
.