Types

• Aluminum Windows
  Extruded aluminum-framed windows, thermally broken for most climates, used for commercial, institutional, and mid- to high-rise punched openings and window walls.
• Awning Windows
  Top-hinged windows that project outward from the bottom, used for ventilation during rain, high or low placements, and stacking with fixed glass.
• Casement Windows
  Side-hinged windows that swing outward with a crank or handle, used for ventilation, egress, and tight air sealing in residential and light commercial work.
• Double-Hung Windows
  Windows with two vertically sliding sashes in one frame, used for traditional residential and institutional facades and flexible top-and-bottom ventilation.
• Fiberglass Windows
  Windows with pultruded fiberglass frames and sashes, used for durable, dimensionally stable, energy-efficient openings in residential and light commercial buildings.
• Fixed Windows
  Non-operable glazed units sealed into a frame, used for views, daylight, and large glass areas where ventilation and egress are not needed.
• Glass Block
  Hollow or solid glass units laid in mortar or set in framed panels to form translucent, light-transmitting walls and windows.
• Glazing
  Architectural glass and its treatments, including annealed, heat-treated, laminated, insulating, and low-e glass used in windows, doors, and glazed walls.
• Greenhouse and Canopy Glazing
  Glass, polycarbonate, and ETFE glazing for greenhouses, conservatories, and sloped canopies that admit daylight overhead.
• Horizontal Sliding Windows
  Windows with one or more sashes sliding sideways on a track, used for wide, low openings and budget residential and multifamily work.
• Skylights and Roof Windows
  Glazed roof openings, including curb- and deck-mounted unit skylights, venting roof windows, and tubular daylighting devices, used to bring daylight and ventilation through roofs.
• Storefront Systems
  Site-glazed aluminum framing systems that hold large glass lites and doors at ground-level entrances and retail fronts.
• Vinyl Windows
  Windows with extruded PVC frames and sashes, welded at the corners, used for residential, multifamily, and budget-sensitive projects.
• Wood and Clad Wood Windows
  Windows with wood frames and sashes, left exposed or clad outside in aluminum or fiberglass, used for residential and high-finish projects needing wood interiors.

Code reference

Always verify the adopted code edition and local amendments for the project jurisdiction.

Governing editions

Structural and wind

• IBC 2024, Section 1609 and ASCE 7-22: wind loads on windows as components and cladding
• IBC 2024, Section 2403.1: each pane marked with manufacturer and type; tempered glass permanently marked
• IBC 2024, Section 2403.2: glass not firmly supported, or under unusual loads, needs design by a registered design professional
• IBC 2024, Section 2403.3: glass is firmly supported where framing deflection perpendicular to the pane does not exceed 1/175 of the glass edge length for edges up to 13'-6", or 1/240 plus 1/4 in. for longer edges (storefront systems)
• IBC 2024, Section 2403.5: louvered windows and jalousies: float, wired, or patterned glass at least 3/16 in. nominal and no longer than 48 in.
• IBC 2024, Section 2404.1: vertical glass (15 degrees or less from vertical) designed for components and cladding wind loads per Section 1609, with glass resistance per ASTM E1300; glazed curtain walls and storefronts meet ASCE 7 Section 13.5.9 seismic requirements (storefront systems, glazing)
• IBC 2024, Section 2404.2: sloped glass (more than 15 degrees from vertical) designed for combined snow, dead, and wind loads per Equations 24-2 through 24-4 (skylights and roof windows)

Flashing and installation

• IBC 2024, Section 1404.4: flashing at the perimeters of exterior door and window assemblies; fenestration flashing per Section 1404.4.1 and sill pan flashing per Section 1404.4.3
• IBC 2024, Section 1503.5: crickets required on the ridge side of penetrations wider than 30 in.; unit skylights flashed per the manufacturer are excepted (skylights and roof windows)

Safety glazing

• IBC 2024, Section 2406.2: safety glazing tested to CPSC 16 CFR 1201, generally Category II, with minimum categories by size and location in Tables 2406.2(1) and (2); ANSI Z97.1 Class A where that standard applies (glazing, storefront systems)
• IBC 2024, Section 2406.3: permanent identification of safety glazing; in multipane assemblies with panes of 1 sq ft or less, one pane marked
• IBC 2024, Section 2406.4.2: glazing within a 24 in. arc of a door edge with bottom edge less than 60 in. above the walking surface
• IBC 2024, Section 2406.4.3: windows are hazardous where all apply: pane over 9 sq ft, bottom edge less than 18 in. above the floor, top edge more than 36 in. above the floor, and a walking surface within 36 in. horizontally; exceptions include a protective rail at 34 in. to 38 in., and outboard IGU panes with bottom edges 8 ft or more above grade
• IBC 2024, Section 2406.4.4: all glazing in guards and railings
• IBC 2024, Section 2406.4.5: glazing at hot tubs, pools, showers, and similar wet surfaces with bottom edge less than 60 in. above the standing surface, unless more than 60 in. horizontally from the water's edge
• IBC 2024, Sections 2406.4.6 and 2406.4.7: glazing at stairs, ramps, landings, and the bottom stair landing with bottom edge less than 60 in. above the walking surface, with listed exceptions
• CPSC 16 CFR 1201: Category I, 150 ft-lb impact, for glazing 9 sq ft or less; Category II, 400 ft-lb, for larger glazing

Skylights and sloped glazing

• IBC 2024, Section 2405.1: applies to glazing more than 15 degrees from vertical, including skylights and sloped walls (skylights and roof windows, greenhouse and canopy glazing)
• IBC 2024, Section 2405.2: allowable materials: laminated glass with at least 30-mil PVB interlayer, wired glass, approved light-transmitting plastic, heat-strengthened glass, or fully tempered glass; annealed glass only under Section 2405.3 exceptions (skylights and roof windows)
• IBC 2024, Section 2405.3: retention screens below heat-strengthened, fully tempered, or wired glazing as listed in 2405.3.1 and 2405.3.2: support twice the glazing weight, No. 12 B&S gage minimum noncombustible, 1 in. by 1 in. maximum mesh, within 4 in. of the glass; exceptions in 2405.3.3 include fully tempered glass 30 degrees or less from vertical with the highest point 10 ft or less above the walking surface, protected walking surfaces, and specified dwelling-unit glazing in R-2, R-3, and R-4 (skylights and roof windows)
• IBC 2024, Section 2405.4: frames noncombustible in Type I and II construction; skylights on roofs sloped less than 45 degrees mounted on a curb at least 4 in. above the roof; curbless allowed on roofs of 14 degrees or more in Group R-3 (skylights and roof windows)
• IBC 2024, Section 2405.5: unit skylights and tubular daylighting devices tested and labeled to AAMA/WDMA/CSA 101/I.S.2/A440, showing manufacturer, labeling agency, product designation, and performance grade (skylights and roof windows)

Glass unit masonry

• IBC 2024, Section 2110.1: glass unit masonry complies with Chapter 14 of TMS 402 and Section 2110 (glass block)
• IBC 2024, Section 2110.1.1: glass block not permitted in fire walls, party walls, fire barriers, fire partitions, smoke barriers, or load-bearing construction; erected with mortar and reinforcement in channel frames, structural frames, masonry or concrete recesses, embedded panel anchors, or other approved joint materials; no wood strip framing in rated walls (glass block)
• IBC 2024, Section 2110.1.1, Exception 1: glass block assemblies with a fire protection rating of at least 3/4 hour may serve as opening protectives under Section 716 in fire barriers, fire partitions, and smoke barriers rated 1 hour or less, but not at exit stairways, exit ramps, or exit passageways (glass block)

Emergency escape (dwellings under the IRC)

• IRC 2024, Section R319.1: emergency escape and rescue openings required (casement, double-hung, sliding, and awning windows used for escape)
• IRC 2024, Section R319.2.1: net clear opening at least 5.7 sq ft (5.0 sq ft at grade floor), at least 24 in. high and 20 in. wide, achieved by normal operation
• IRC 2024, Section R319.4.2: area wells deeper than 44 in. need a permanent ladder or steps usable with the window open

Energy

• IECC 2024, Section C402: fenestration U-factor and SHGC, skylight area and performance, and air leakage for commercial buildings; residential fenestration under the residential provisions; ratings determined by NFRC procedures

Referenced standards

Sources

• UpCodes: 2024 IBC Chapter 24 glass and glazing (Department of Defense adoption), https://up.codes/viewer/department-of-defense/ibc-2024/chapter/24/glass-and-glazing
• UpCodes: 2024 IBC Chapter 14 exterior walls, https://up.codes/viewer/department-of-defense/ibc-2024/chapter/14/exterior-walls
• UpCodes: 2024 IBC Chapter 15 roof assemblies, Chapter 15 Roof Assemblies and Rooftop Structures: Department of Defense Building Code 2024 | UpCodes
• Jefferson County, CO: emergency escape and rescue openings (2024 IRC), https://www.jeffco.us/2081/Emergency-Escape-Rescue-Openings
• GPO: 16 CFR 1201.2, https://www.gpo.gov/fdsys/pkg/CFR-2014-title16-vol2/pdf/CFR-2014-title16-vol2-sec1201-2.pdf
• FGIA: NAFS-22, https://store.fgiaonline.org/101/I.S.2/A440-22/
• GoCodeBook: California Building Code 2110 glass unit masonry (transcription of 2024 IBC), https://gocodebook.com/library/us/ca/ca-building-code/chapter-21-masonry/section-2110-glass-unit-masonry