ACG · Reference · Updated May 13, 2026

Commercial storefront glazing glossary

50+ commercial storefront, curtainwall, and glazing terms defined alphabetically. Terms are tagged: Florida Only for terms specific to Florida code and product approval (HVHZ, NOA, TAS, FBC, FPA, WBDR) and General for industry-wide terms that apply in all jurisdictions (IBC, ASTM, ANSI, CPSC, and standard construction terminology). Intended for general contractors, architects, owners, and project managers working on Florida commercial glazing projects.

Florida Only  — applies to Florida code and product approval General  — applies in all jurisdictions

By American Commercial Glass · FL CGC #1531993 · 350+ Florida commercial projects · 1M+ SF installed

A

Anchor / AnchorageGeneral
The mechanical connection between a glazing frame and the building structure. Anchors may be embedded in concrete, threaded into CMU, or welded to structural steel. Anchor type, spacing, and edge distance are specified by the system manufacturer in the installation instructions and, for HVHZ systems, in the NOA anchorage detail.
Annealed glassGeneral
Standard float glass that has been slowly cooled during manufacturing to relieve internal stress. Annealed glass is the base material from which heat-strengthened and tempered glass are produced. When broken, annealed glass fractures into large, sharp shards. It is the lowest structural grade of glass and generally cannot be used as a glazing lite without additional heat treatment for commercial applications requiring safety or impact compliance.
ANSIGeneral
American National Standards Institute. The organization that oversees the development of voluntary consensus standards in the U.S. ANSI A156 series governs door hardware performance (closers, exit devices, locksets, operators). Not a regulatory body; ANSI standards become mandatory when referenced by a building code or product specification.
ASCE 7General
Minimum Design Loads and Associated Criteria for Buildings and Other Structures, published by the American Society of Civil Engineers. The primary reference for wind load calculation in U.S. building codes including the FBC. Provides wind speed maps, exposure category definitions, and calculation methodology for component and cladding pressures on glazed openings.
ASTMGeneral
ASTM International, formerly the American Society for Testing and Materials. Publishes the test standards referenced in most glazing specifications. Key ASTM standards in commercial glazing: E330 (structural performance), E331/E547 (water penetration), E283 (air infiltration), E1105 (field water test), E1886/E1996 (impact resistance, WBDR), E2112 (installation practice), E774 (insulating glass unit durability).
ASTM E1105General
Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls. Used to verify installed performance at completion and for water intrusion diagnostics. Applies water at a calibrated rate while maintaining a static air pressure differential across the test specimen.
ASTM E2112General
Standard Practice for Installation of Exterior Windows, Doors, and Skylights. Covers rough opening preparation, flashing, sealant application, and dimensional tolerance requirements for exterior glazing system installation. Referenced by most commercial glazing manufacturer installation instructions.

B

Bite / Glass BiteGeneral
The dimension by which the glazing pocket retains the edge of the glass lite — measured from the glazing pocket face to the glass edge. Minimum bite is specified by the manufacturer and affects the structural adequacy of the glass retention. Too little bite can allow glass to jump out of the frame under wind load; too much bite can cause glass edge stress from thermal cycling.
Backer rodGeneral
A closed-cell foam rod inserted into a sealant joint before sealant application to control joint depth and prevent three-point adhesion. The backer rod ensures the sealant can move in tension and compression as the joint expands and contracts. Sized to be approximately 25% larger than the joint width for a snug fit.

C

CMU (Concrete Masonry Unit)General
Standard hollow concrete block used as the primary wall substrate in much of Florida's commercial low-rise construction. CMU cells adjacent to glazing frame anchor locations must be fully grouted and solid for anchor bolt installation. NOAs specify minimum compressive strength and acceptable fastener types for CMU substrates.
CPSCGeneral
Consumer Product Safety Commission. Publishes 16 CFR Part 1201 and 16 CFR Part 1202, the federal safety glazing standards for architectural glass in hazardous locations. CPSC standards require safety glazing (tempered, laminated, or other approved types) in specific locations defined by glazing area, height, and proximity to walking surfaces and doors. FBC and IBC reference CPSC standards for safety glazing requirements.
CurtainwallGeneral
A non-load-bearing exterior cladding system that spans multiple floors, anchoring to the building structure at each floor level. Curtainwall carries only its own dead load (glass and frame weight) — it does not carry floor or roof loads. Available in stick-built (field-assembled) and unitized (factory-assembled panel) forms. Curtainwall is typically specified for mid-rise and high-rise buildings where storefront's floor-to-ceiling span is insufficient.
Cyclic loadingGeneral
Repeated oscillating pressure applied to a glazing system to simulate sustained wind gusting. TAS 203 specifies 9,000 cycles of pressure differential for HVHZ certification. ASTM E1996 specifies cyclic loading protocols for WBDR testing. Cyclic loading tests identify fatigue failure modes that static pressure testing cannot reveal.

D

Design Pressure (DP)General
The wind load (in PSF) a glazing system is rated to withstand, with separate positive (windward push) and negative (leeward suction) values. DP is calculated per ASCE 7 based on building location, height, exposure category, and building geometry. A system's NOA or FPA specifies maximum allowable DP at each tested frame size. The installed system must be rated to at least the project's calculated DP at the actual opening dimensions.
Division 08General
The CSI MasterFormat division covering Openings — doors, windows, glazing, storefronts, curtainwall, hardware, and related products. Division 08 specifications govern the performance, materials, installation, and testing requirements for commercial glazing systems on a project.
Dry glaze / Dry-glazedGeneral
A glazing method in which the glass is retained in the glazing pocket by compression gaskets rather than by a liquid sealant. The gasket creates a mechanical seal against the glass surface. Dry-glazed systems allow glass replacement without sealant removal and can be re-glazed repeatedly if gaskets are maintained. Compare to wet-glazed.

E

Expansion jointGeneral
A designed gap in the storefront framing system, filled with a flexible sealant, that allows the aluminum frame to expand and contract with temperature changes without transferring stress to glass or anchors. Aluminum's coefficient of thermal expansion requires expansion joints at intervals (typically every 20–25 feet) in long runs of storefront framing. Omitting expansion joints causes glass stress fractures and sealant failure.
Exposure categoryGeneral
An ASCE 7 classification (B, C, or D) describing the surface roughness of the terrain surrounding a building. Exposure D (open water, flat terrain) produces the highest wind pressures. Exposure C (open terrain with scattered obstructions) is common for Florida coastal commercial sites. Exposure B (suburban or urban areas with significant building cover) produces lower pressures. Exposure category is determined by the structural engineer and affects the calculated DP for each glazed opening.

F

FBC (Florida Building Code)Florida Only
The Florida Building Code, adopted and administered by the Florida Department of Business and Professional Regulation. The FBC is based on the International Building Code (IBC) with Florida-specific amendments, including more stringent wind and hurricane provisions than the base IBC. Updated on a regular cycle; the current edition is the 8th Edition (2023). Section 1609 governs wind loads and the protection of openings.
FBC 1609Florida Only
Section 1609 of the Florida Building Code (Chapter 16, Structural Design). Governs wind loads on buildings and the protection of exterior glazed openings. Section 1609.1.2 requires impact-resistant glazing or covers in WBDR and HVHZ jurisdictions. References ASCE 7 for wind load calculation methodology.
FPA (Florida Product Approval)Florida Only
Florida Product Approval is the product certification system administered by the Florida Department of Business and Professional Regulation for building products installed in Florida. An FPA certifies a glazing system for use in WBDR (non-HVHZ) Florida locations based on ASTM E1886/E1996 impact testing. An FPA is not sufficient for HVHZ installation — HVHZ requires a Miami-Dade NOA.
Frame — aluminum extrusionGeneral
The primary structural members of a storefront, curtainwall, or window wall system, formed by extruding aluminum alloy (typically 6063-T5 or 6061-T6) through a die to produce the required cross-section. Frame members include verticals (mullions), horizontals (head and sill rails, intermediate horizontals), and ancillary extrusions (cover caps, glazing stops, thermal break components).

G

GasketGeneral
An elastomeric seal — typically EPDM (ethylene propylene diene monomer) or neoprene — used in dry-glazed systems to retain glass in the glazing pocket and provide a weathertight seal without liquid sealant. Gaskets are available in bulb, blade, and fin profiles and must maintain their compression seal over the service life of the installation. UV exposure and ozone cause gasket hardening and eventual failure, particularly in Florida.
Glazing pocketGeneral
The channel in the aluminum frame extrusion that receives and retains the edge of the glass lite. The glazing pocket dimensions — depth and width — are sized by the manufacturer to accommodate the glass thickness and bite requirements for the system's rated DP. In wet-glazed systems, the pocket is filled with sealant around the glass edge. In dry-glazed systems, gaskets fill the pocket against the glass.
Glass make-upGeneral
The complete specification of a glass unit including the number of lites, thickness of each lite, heat treatment of each lite (annealed, heat-strengthened, tempered), any laminate interlayer (PVB or SGP, and interlayer thickness), airspace dimensions (for IGUs), and coating type and position. The glass make-up listed in a system's NOA or FPA is the configuration that was tested and approved — substituting any element requires re-evaluation.

H

HeadGeneral
The top horizontal framing member of a door or window opening, or the top extrusion member of a storefront frame. The head extrusion spans between vertical mullions or jambs and receives the top edge of glass lites. The head detail is particularly important for water management — the transition at the head between the storefront frame and the wall assembly above must be properly flashed to prevent water intrusion.
Heat-strengthened glassGeneral
Glass that has been heated to near-softening temperature and then air-quenched at a controlled rate, producing a surface compression approximately twice that of annealed glass. Heat-strengthened glass is stronger than annealed glass and more resistant to thermal stress. When broken, it fractures into large pieces similar to (but smaller than) annealed glass. Heat-strengthened glass is not considered a safety glazing material and cannot substitute for tempered glass in CPSC-required safety glazing locations.
HVHZ (High Velocity Hurricane Zone)Florida Only
The most stringent wind-load protection designation in the Florida Building Code, applying to Miami-Dade and Broward counties. HVHZ requires that all exterior glazed openings carry a current Miami-Dade NOA based on TAS 201, 202, and 203 testing protocols. HVHZ was established in the FBC following Hurricane Andrew (1992).

I

IBC (International Building Code)General
The International Building Code, published by the International Code Council (ICC). The base model building code adopted with amendments by most U.S. states. Florida adopts the IBC as the base of the Florida Building Code (FBC) and amends it with Florida-specific provisions, particularly for wind and hurricane resistance. IBC Chapter 24 covers glazing.
IGU (Insulating Glass Unit)General
A glass assembly consisting of two or more lites separated by a hermetically sealed airspace (or gas fill — typically argon). IGUs provide thermal insulation performance measured as U-factor and solar heat gain coefficient (SHGC). The perimeter spacer contains desiccant to absorb any moisture in the sealed airspace. IGU seal failure results in visible fogging between the panes and requires unit replacement.
Impact-resistant glazingGeneral
A glazing system tested and certified to resist penetration by wind-borne debris under simulated hurricane conditions. For WBDR Florida projects, impact resistance is proven via ASTM E1886/E1996 large-missile and small-missile testing. For HVHZ projects, the additional TAS 201 large-missile test (9 lb 2x4 at 50 ft/sec) plus TAS 202 and TAS 203 are required. Impact-resistant glazing typically uses laminated glass with PVB or SGP interlayer.

J

JambGeneral
The vertical framing member at the side of a door or window opening, or the vertical extrusion at the edge of a storefront frame at the transition to the surrounding construction. The jamb extrusion is typically the anchor point for the frame-to-substrate connection. Perimeter sealant is applied at the jamb between the frame and the surrounding construction material.

L

Laminated glassGeneral
A glass assembly consisting of two or more glass lites bonded together with a plastic interlayer (PVB or SGP) under heat and pressure. When broken, the interlayer holds the glass fragments together, preventing penetration and maintaining the glass in the frame. Required for impact-rated applications in WBDR and HVHZ. Laminated glass with SGP interlayer provides superior post-breakage structural performance compared to standard PVB interlayer.
Low-E coatingGeneral
A microscopically thin metallic or metallic-oxide coating applied to one surface of a glass lite, designed to reduce heat transfer through the glass by reflecting infrared radiation. Low-E coatings reduce solar heat gain (reducing cooling loads in Florida) and reduce interior surface temperature radiation (reducing heating loads in winter climates). Coating position within an IGU unit (surface 2, 3, or other) affects its thermal performance characteristics.

M

MullionGeneral
A vertical framing member in a storefront or curtainwall system that separates adjacent lites of glass and spans between horizontal members. Mullions carry the structural load of glass and frame weight, resist wind pressure, and provide the primary lateral stiffness of the glazing system. Mullion depth is sized by the manufacturer for the required span and design pressure.

N

NOA (Notice of Acceptance)Florida Only
A Notice of Acceptance is a product approval document issued by Miami-Dade County Product Control, certifying that a building product — including glazing systems — has been tested to the HVHZ protocols (TAS 201, 202, and 203) and is approved for installation in Miami-Dade and Broward counties. Each NOA specifies the tested system configuration, maximum frame size, design pressure, glass make-up, and anchorage. NOAs are valid approximately 5 years and are public records searchable at the Miami-Dade Product Control website.

P

PVB (Polyvinyl Butyral)General
The standard plastic interlayer material in laminated glass. PVB is a thermoplastic film bonded between glass lites under heat and pressure. It holds glass fragments in place after breakage and provides the primary penetration resistance in impact-rated glazing. Standard PVB interlayer thickness for HVHZ applications is typically 0.090" (90 mil). Compare to SGP (SentryGlas Plus), which provides higher post-breakage structural performance than standard PVB.
Perimeter sealantGeneral
The sealant joint between the glazing frame and the surrounding building construction (concrete, CMU, steel, GFRC). The perimeter sealant is the primary weather seal at the frame-to-substrate interface and must accommodate thermal movement between the aluminum frame and the substrate. High-quality silicone is the standard material. Service life in Florida's UV environment is typically 5–7 years before replacement is required.

R

Rough openingGeneral
The opening in the building construction — concrete, CMU, or framing — into which the glazing system frame is installed. The rough opening is slightly larger than the nominal frame dimension to allow shimming and tolerance adjustment. Rough opening tolerances per ASTM E2112 define the maximum allowable deviation in width, height, plumb, level, and squareness before frame installation.

S

SealantGeneral
An elastomeric compound applied to joints and interfaces in a glazing system to prevent air and water infiltration and accommodate movement. Glazing applications use silicone, polyurethane, or butyl sealants. Silicone is the standard for exposed exterior joints due to UV resistance, temperature range, and long service life. Sealant compatibility with adjacent materials (frame finish, glass coating, substrate, backer rod, other sealants) must be verified before specification.
SGP (SentryGlas Plus)General
A high-performance ionoplast interlayer for laminated glass, with significantly higher stiffness and post-breakage structural strength than standard PVB interlayer. SGP laminated glass is specified for high-DP applications in Florida where the glass must retain structural integrity after breakage, and for applications where post-breakage sagging of a large laminated lite would be unsafe or damaging.
SillGeneral
The bottom horizontal framing member of a storefront opening or window frame. The sill extrusion includes weep slots or weep baffles for drainage of any water that penetrates the glazing pocket. The sill is the most water-vulnerable part of a storefront system; sill detail design, weep placement, and perimeter sealant at the sill-to-substrate interface are critical for water management.
Stick-builtGeneral
A glazing installation method in which the frame is assembled piece-by-piece in the field from individual extrusions (vertical mullions, horizontal rails, cover caps) delivered separately. Stick-built is the standard method for storefront and is common for curtainwall on low-rise projects. Contrast with unitized, in which complete panels are factory-assembled and installed as units at the jobsite.
SubmittalGeneral
The package of project-specific technical documentation prepared by the glazing subcontractor and submitted to the design team for review and approval before fabrication and installation. A commercial glazing submittal includes shop drawings, product data sheets, NOA or FPA documentation, glass make-up specifications, hardware schedule, sealant schedule, and anchorage details. Approved submittals become the contract document for the glazing scope.

T

TAS 201Florida Only
Testing Application Standard 201 — Large Missile Impact Test. One of the three HVHZ test protocols required for Miami-Dade NOA certification. TAS 201 fires a 9-pound 2x4 wood projectile at the glazing specimen at 50 feet per second. Pass criteria: the projectile does not penetrate through the system; the glazing may break but must remain in the frame. Part of the Florida-specific TAS testing sequence not required in non-HVHZ jurisdictions.
TAS 202Florida Only
Testing Application Standard 202 — Structural Performance Test. Applies uniform static air pressure to verify the system meets its rated design pressure. Pass criteria: no glass breakage and no permanent deformation beyond limits at the rated DP. The structural counterpart to TAS 201 in the HVHZ testing sequence.
TAS 203Florida Only
Testing Application Standard 203 — Cyclic Wind Pressure Loading Test. Applies 9,000 cycles of positive and negative air pressure differential, simulating sustained hurricane-force wind gusting. Tests for fatigue failure modes not detectable in static pressure testing. Pass criteria: system maintains air, water, and structural integrity through the full cycle count. Required for HVHZ NOA certification.
Tempered glassGeneral
Glass that has been heated to near-softening temperature and rapidly quenched to produce a high surface compression (approximately 4–5× that of annealed glass). Tempered glass is significantly stronger than annealed glass and, when broken, fractures into small, relatively blunt cubes rather than large shards. This fracture pattern qualifies tempered glass as a safety glazing material under CPSC standards. Tempered glass cannot be cut or drilled after tempering — all holes and notches must be made before the tempering process.
Thermal breakGeneral
A non-metallic barrier incorporated into an aluminum frame extrusion to interrupt the metallic conduction path between the exterior and interior faces of the frame. Thermal break systems significantly reduce heat transfer through the frame, improving the U-factor of the overall glazing assembly. Common thermal break materials include polyamide strips and poured-and-debridged polyurethane. Required for energy code compliance in most commercial specifications in conditioned buildings.

U

Unitized curtainwallGeneral
A curtainwall system in which complete floor-to-floor panels — including frame, glass, and all internal components — are factory-assembled and shipped to the jobsite for crane installation as complete units. Unitized systems offer faster field installation and higher factory quality control than stick-built curtainwall, but require tighter slab-edge tolerances and more detailed pre-installation coordination. Common in mid-rise and high-rise buildings where field assembly labor is a major cost driver.

W

WBDR (Wind-Borne Debris Region)Florida Only
A designation in the Florida Building Code for areas where wind speeds reach 130 mph or more at 10 meters above ground, approximately following the Florida coastline and inland areas in South Florida. In WBDR, exterior glazed openings must be protected by impact-rated glazing with Florida Product Approval (FPA) or by rated impact-resistant shutters or panels. HVHZ (Miami-Dade and Broward) is a more stringent subset of WBDR requiring Miami-Dade NOA.
Weep systemGeneral
The drainage features built into a storefront sill extrusion — weep slots (open holes at the exterior face of the sill), weep baffles (internal drainage channels), and weep tubes — that drain water collected inside the sill cavity to the exterior. A functioning weep system is essential for storefront water management. Blocked weeps cause sill cavity water accumulation and interior leaks. Annual inspection and clearance of weep slots is standard maintenance practice.
Wet glaze / Wet-glazedGeneral
A glazing method in which a liquid sealant — typically silicone — is applied inside the glazing pocket to seal the glass to the frame. The wet sealant fills voids around the glass edge and adheres to both the glass and the frame, creating a weathertight seal. Wet-glazing is used where the precise seal quality achievable with liquid sealant is preferred over gasket compression seals. Compare to dry-glazed.
Window wallGeneral
A non-load-bearing glazing system spanning from slab edge to slab edge within a single story, with the frame bearing on the structural slab below. Window wall is intermediate between storefront (which anchors at head and sill within the wall opening) and curtainwall (which spans multiple floors). Window wall offers larger glass areas than typical storefront while maintaining floor-by-floor installation sequencing. Common in mid-rise residential and mixed-use construction.

FAQ — glazing glossary

What is the difference between storefront, curtainwall, and window wall?

Storefront spans from floor to ceiling within a single story and anchors at head and sill. Curtainwall spans multiple floors and anchors at each floor level, carrying its own dead load. Window wall spans slab-to-slab within one story, with the frame bearing on the slab — a hybrid between the two.

What is an NOA (Notice of Acceptance)?

A Florida product approval document issued by Miami-Dade County Product Control, certifying a glazing system has passed HVHZ testing (TAS 201/202/203) and is approved for Miami-Dade and Broward installation. NOAs specify system configuration, maximum frame size, DP rating, glass make-up, and anchorage details.

What is design pressure (DP) in glazing?

DP is the wind load in PSF a glazing system is rated to withstand, with positive (push) and negative (suction) values. Calculated from ASCE 7 using building location, height, and exposure. The system's NOA must rate to the project's calculated DP at the actual opening size.

What is the difference between a Florida-only term and a general industry term?

Florida-specific terms (tagged Florida Only) include HVHZ, NOA, TAS 201/202/203, FBC, FPA, and WBDR. These apply only in Florida's code and product approval context. General terms (tagged General) apply nationally: IBC, ASTM standards, ANSI standards, CPSC, and standard glazing construction terminology.

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