11.1 Doors, Windows, Glazing, and Hardware
Key Takeaways
- Egress doors require a minimum 32-inch clear width and 80-inch clear height; doors serving an occupant load of 50 or more swing in the direction of egress travel (IBC Chapter 10).
- Fire-door ratings are a fraction of the wall rating (e.g., 3 hr door in a 4 hr fire wall) and must be self-closing, self-latching, and labeled per NFPA 80.
- Safety glazing (tempered or laminated) is required in doors, near doors, in low walking-surface locations, and wet areas per IBC Chapter 24.
- R-value equals 1 divided by U-factor; lower U-factor and lower SHGC mean better window energy performance per the NFRC label.
- ADA/ICC A117.1 favors lever hardware; panic hardware is required for Group A and E occupancies with 50-plus occupants.
Doors, Windows, Glazing, and Hardware
Construction Specifications Institute (CSI) Division 08 — Openings covers doors, frames, windows, glazing, and door hardware. On the NASCLA Accredited Commercial General Building Contractor exam this material is tested against the International Building Code (IBC) Chapters 7 (fire-rated assemblies), 10 (egress), and 24 (glazing). Because this is an open-book exam, learn where the rule lives, not just the number.
Egress door requirements (IBC Chapter 10)
Egress doors must be side-hinged swinging in most occupancies. Memorize the dimensional limits:
- Clear width: minimum 32 inches (door open 90 degrees, measured face of door to stop).
- Clear height: minimum 80 inches.
- Single leaf max width: 48 inches nominal.
- Swing direction: doors serving an occupant load of 50 or more, or a Group H occupancy, must swing in the direction of egress travel.
A common trap: a 36-inch door does not give 36 inches clear — subtract the stop and the door thickness. Expect about 32 to 34 inches clear, which still satisfies code.
Fire door assemblies (IBC Chapter 7, NFPA 80)
Fire-door ratings are a fraction of the wall rating because doors close to interrupt fire, not contain it indefinitely. The exam loves this table:
| Wall assembly rating | Required door rating | Typical use |
|---|---|---|
| 4 hr | 3 hr | Fire walls |
| 3 hr | 3 hr | Fire walls (alt.) |
| 2 hr | 1-1/2 hr | Shaft, exit enclosure |
| 1 hr exit enclosure | 1 hr | Stairways |
| 1 hr (other) | 3/4 hr | Corridor, smoke barrier |
| 1/2 hr | 1/3 hr (20 min) | Corridor (smoke) |
Fire doors are self-closing and self-latching and carry a permanent label. Field modification voids the label.
Glazing and safety glazing (IBC Chapter 24)
Safety glazing (tempered or laminated, per ANSI Z97.1 / CPSC 16 CFR 1201) is required in hazardous locations:
- Glazing in doors and within a 24-inch arc of the door edge if the bottom is below 60 inches.
- Glazing where the bottom edge is below 18 inches above the floor (walking-surface rule), the top is above 36 inches, the pane exceeds 9 square feet, and a walking surface is within 36 inches.
- Glazing in wet areas (tub/shower) where the bottom edge is below 60 inches.
Tempered glass is roughly 4 times stronger than annealed and breaks into small dice. Laminated glass holds fragments on a polyvinyl-butyral interlayer.
Energy: U-factor, SHGC, and R-value
Window thermal performance is rated by U-factor (rate of heat loss — lower is better) and Solar Heat Gain Coefficient (SHGC) (fraction of solar heat admitted — lower reduces cooling load). U-factor is the inverse of R-value: a window with U-0.30 has an effective R of about 3.3 (R = 1 / U). Whole-wall and roof R-values are far higher; do not confuse a U-0.30 window with an R-30 ceiling. National Fenestration Rating Council (NFRC) labels report these values.
Door hardware and accessibility
Under the ICC A117.1 / ADA standard, operable hardware must be usable without tight grasping, pinching, or twisting of the wrist — favor lever handles over knobs. Mounting height for operable parts is 34 to 48 inches above the floor. Panic hardware (listed exit devices) is required on egress doors in assembly (A) and educational (E) occupancies with an occupant load of 50 or more, and in Group H. Maximum opening force for interior non-fire doors is 5 pounds.
An egress door serves a meeting room with an occupant load of 75. Which requirement applies?
A window is labeled U-0.25 by the NFRC. What is its approximate effective R-value?
Fire-Rated Openings and Egress Hardware
Openings in fire-rated walls need fire-rated, labeled assemblies: a door in a 1-hour wall typically needs a 45-minute rated door (ratings are less than the wall because the wall has more mass), with a self-closing device and positive latching. Fire doors must never be propped open (unless on a listed hold-open that releases on alarm). Egress doors swing in the direction of travel for occupant loads of 50+, and exit doors use panic hardware that opens with a single motion under one operation.
Safety Glazing and Performance Ratings
Safety glazing (IBC 2406) — tempered or laminated — is required in hazardous locations: doors, sidelites, glazing within 24 in of a door and ≤60 in above the floor, tub/shower enclosures, and large low panels. Tempered glass shatters into pebbles; laminated holds together on an interlayer. Windows carry NFRC labels for U-factor and SHGC (solar heat gain coefficient); the IECC limits both by climate zone. Each labeled safety pane carries a permanent etched bug.
Hardware (the Finish Hardware Schedule)
Hinges, locksets, closers, exit devices, thresholds, and weatherstripping are listed in the hardware schedule keyed to the door schedule. ADA requires lever (not knob) hardware, operable with one hand without tight grasping/twisting, mounted 34–48 in above the floor, with a maximum 5 lb opening force on interior doors. Coordinate handing (left/right) at order time.
Common Exam Traps
- Trap: A 1-hour wall needs a 1-hour door. It typically needs a 45-minute labeled door.
- Trap: Round knobs satisfy ADA. Lever hardware is required.
- Trap: Annealed glass beside a door is fine. Safety glazing is required in hazardous locations.
- Trap: Propping a fire door open with a wedge.
Glazing is being installed in a fixed panel adjacent to a door, within 24 inches of the door and 40 inches above the floor. What is required?