Commercial storefront door systems are available in narrow stile, medium stile, and wide stile configurations, each designed for different traffic levels and glass area requirements. Glass options for storefront doors include tempered, laminated, insulated, and low e. This reference guide covers storefront door types, and glass specifications and the factors that determine which system to specify for a commercial project.
CDF Distributors supplies storefront door assemblies from its Nashville, Tennessee headquarters. You can configure and order complete door assemblies online using CDF’s ProBuilder tool at cdfdistributors.com. For assistance selecting the correct glass type or storefront configuration for your project, call (855) 769-9895 or email sales@cdfdoors.com.
About This Guide
This reference guide is published by CDF Distributors, a commercial door and hardware supplier headquartered in Nashville, Tennessee. CDF fabricates hollow metal door and frame assemblies in-house and supplies storefront door systems, glass, and hardware to contractors, facility managers, and building owners across the United States. The technical specifications in this guide reflect current industry standards, building code requirements, and CDF’s product engineering documentation.
Storefront Door Stile Types
Storefront doors are aluminum-framed glass doors used in commercial entrances, retail storefronts, office lobbies, and institutional buildings. The stile is the vertical framing member on each side of the door. Stile width determines the structural capacity of the door, the visible glass area, and compatibility with different hardware types. The three standard stile widths are narrow, medium, and wide.
Narrow Stile Storefront Doors
Narrow stile storefront doors have vertical framing members that are typically 2-1/4 inches to 3 inches wide. These doors maximize the visible glass area and are used in low-traffic commercial entrances where a clean, minimal appearance is the priority. Narrow stile doors accept a limited range of lock hardware due to the reduced stile width, making them most suitable for entrances controlled by overhead closers, pivots, or narrow-profile locks.
Stile Width | 2-1/4” to 3” |
Glass Area | Maximum visible glass |
Traffic Level | Low to moderate |
Hardware Compatibility | Narrow-profile locks, overhead closers, pivots |
Common Applications | Retail storefronts, office lobbies, showrooms |
Medium Stile Storefront Doors
Medium stile storefront doors have vertical framing members that are typically 3-1/2 inches to 4-1/2 inches wide. These doors balance glass visibility with hardware compatibility and are the most commonly specified storefront door type for general commercial use. Medium stile doors accept a wider range of cylindrical and mortise lock hardware than narrow stile doors.
Stile Width | 3-1/2” to 4-1/2” |
Glass Area | Balanced glass and frame |
Traffic Level | Moderate to high |
Hardware Compatibility | Cylindrical locks, mortise locks, exit devices, closers |
Common Applications | Commercial entrances, hospitals, schools, office buildings |
Wide Stile Storefront Doors
Wide stile storefront doors have vertical framing members that are 5 inches or wider. These doors accommodate the full range of commercial hardware including exit devices (panic bars), heavy-duty mortise locks, and electric strikes. Wide stile doors are specified for high-traffic entrances and code-required exit locations where exit devices must be installed.
Stile Width | 5” and wider |
Glass Area | Reduced glass, wider frame |
Traffic Level | High |
Hardware Compatibility | Full range including exit devices (panic bars), electric strikes |
Common Applications | High-traffic entrances, code-required exits, institutional buildings |
Storefront Door Stile Comparison
The following table compares the three storefront door stile types across key specification factors.
Factor | Narrow Stile | Medium Stile | Wide Stile |
Stile Width | 2-1/4” to 3” | 3-1/2” to 4-1/2” | 5” and wider |
Glass Visibility | Maximum | Balanced | Reduced |
Hardware Range | Limited | Broad | Full |
Exit Devices | Not compatible | Select models | Full compatibility |
Traffic Suitability | Low to moderate | Moderate to high | High |
Cost | Lower | Mid-range | Higher |
Side-by-side illustration showing narrow stile, medium stile, and wide stile door profiles with dimensions labeled. This diagram requires CDF approval before inclusion in the production file.
Glass Types for Storefront Doors and Lite Kits
Glass selection for storefront doors and hollow metal door lite kits depends on the application, fire rating requirements, energy code compliance, and security needs. The four primary glass types used in commercial door applications are tempered, laminated, insulated, and wired glass. Each type has distinct performance characteristics that determine where it can and cannot be used.
Tempered Glass
Tempered glass is manufactured through a process of extreme heating and rapid cooling that increases its strength to approximately ten times that of standard annealed glass. When tempered glass breaks, it fractures into small, rounded pebbles rather than large, sharp shards. This breakage pattern is the reason tempered glass is classified as safety glass under ANSI Z97.1 and CPSC 16 CFR 1201.
Tempered glass is the standard glass type for storefront doors, sidelites, and most commercial lite kit applications. It is required by code in all locations where human impact is possible, including doors, sidelites adjacent to doors, and glass panels within 18 inches of the floor. Tempered glass is the most cost-effective safety glass option for non-fire-rated applications.
Strength | Approximately 10x stronger than annealed glass |
Break Pattern | Small, rounded pebbles without sharp edges |
Safety Standard | ANSI Z97.1, CPSC 16 CFR 1201 |
Fire Rating | Not fire-rated (use wired or fire-rated ceramics for rated openings) |
Common Applications | Storefront doors, sidelites, lite kits in non-rated hollow metal doors |
Limitations | Cannot be cut or modified after tempering; must be ordered to exact size |
Laminated Glass
Laminated glass consists of two or more layers of glass bonded together with a polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) interlayer. When laminated glass breaks, the fragments adhere to the interlayer rather than falling free. This characteristic makes laminated glass the preferred choice for security, forced-entry resistance, sound attenuation, and hurricane-rated applications.
In storefront door applications, laminated glass is specified when the opening requires impact resistance beyond what tempered glass provides, or when the glass must remain in the frame after breakage. Laminated glass is also used in overhead glazing and sloped applications where falling glass fragments pose a safety hazard.
Construction | Two or more glass layers with PVB or EVA interlayer |
Break Pattern | Cracks but fragments remain bonded to interlayer |
Safety Standard | ANSI Z97.1, CPSC 16 CFR 1201, ASTM E1300 |
Fire Rating | Specialty fire-rated laminated products available for 20-minute through 90-minute ratings |
Common Applications | Security glazing, hurricane zones, sound attenuation, overhead glazing |
Limitations | Higher cost than tempered; thicker overall assembly; interlayer can delaminate over time if not specified correctly |
Insulated Glass
Insulated glass units (IGUs) consist of two or more panes of glass separated by a sealed air space or gas-filled cavity. The air space, typically filled with argon or krypton gas, reduces thermal transfer through the glazing. Insulated glass is specified for storefront doors and curtain wall systems where energy code compliance requires specific U-factor or Solar Heat Gain Coefficient (SHGC) performance values.
For storefront door applications, insulated glass units are commonly built with tempered glass on both the interior and exterior lites. Low-E coatings are applied to one or more surfaces to further reduce heat transfer. Insulated glass units are thicker than single-pane glazing, which affects the door stile depth and glazing pocket dimensions.
Construction | Two or more glass panes with sealed air or gas-filled cavity |
Thermal Performance | Significantly reduced U-factor compared to single glazing |
Gas Fill Options | Air, argon, krypton |
Coating Options | Low-E coatings on one or more surfaces |
Common Applications | Energy code-compliant storefronts, exterior entrances, climate-controlled buildings |
Limitations | Thicker overall assembly; heavier weight; seal failure over time can cause fogging |
Glass Type Comparison
The following table compares the four primary glass types used in commercial storefront door and lite kit applications.
Property | Tempered | Laminated | Insulated | |
Strength vs. Annealed | ~10x | ~2x (varies by layup) | Depends on lite type | |
Safety Glazing | Yes | Yes | Yes (if tempered lites) | |
Fire-Rated Options | No | Specialty products only | No (standard IGU) | |
Thermal Performance | Standard | Standard | High | |
Security/Impact | Moderate | High | Moderate | |
Relative Cost | Low | Moderate | Moderate to high |
When to Specify a Storefront System
Storefront door systems are the appropriate choice when the opening requires maximum glass area, the location is a primary entrance or retail-facing facade, the opening does not require a fire rating, and the design intent emphasizes transparency and visibility. Storefront systems are also specified for curtain wall and ribbon window applications where the door integrates with a larger glazing system.
Specify a storefront door system when:
- The opening is an exterior entrance or lobby
- Maximum glass visibility is required
- No fire rating is required for the opening
- The door integrates with an aluminum storefront or curtain wall framing system
- The design intent prioritizes transparency
Glass Specification Considerations
Selecting the correct glass type for a storefront door or lite kit requires evaluating several project-specific factors. The following considerations apply to both storefront and hollow metal door applications.
- Fire rating requirements for the opening and the wall assembly
- Safety glazing requirements at the specific location (CPSC 16 CFR 1201 and ANSI Z97.1)
- Energy code compliance (U-factor, SHGC) for exterior glazing
- Security and forced-entry resistance requirements
- Sound attenuation (STC rating) requirements
- Impact resistance for hurricane or tornado zones
- Maximum glass size allowed by the fire test listing (for rated assemblies)
- Door and frame glazing pocket depth (insulated glass units require deeper pockets)
CDF Distributors verifies glass compatibility with the door, frame, and fire rating for every assembly. When configuring an order through ProBuilder, glass options are filtered to show only compatible selections for the specified door, frame, and rating combination.
Industry Standards Referenced
The following industry standards govern glass selection, safety glazing, fire-rated assemblies, and storefront door performance in commercial construction.
ANSI Z97.1 | Safety glazing materials used in buildings; impact test standard |
CPSC 16 CFR 1201 | Federal safety standard for architectural glazing materials |
ASTM E119 | Standard test method for fire tests of building construction and materials |
ASTM E1300 | Standard practice for determining load resistance of glass in buildings |
UL 10C | Positive-pressure fire test for door assemblies |
NFPA 80 | Standard for fire doors and other opening protectives |
NFPA 252 | Standard methods of fire tests of door assemblies |
IBC Chapter 24 | International Building Code glass and glazing requirements |
AAMA/WDMA/CSA 101/I.S.2/A440 | North American Fenestration Standard for windows, doors, and skylights |
Configure Your Door and Glass Assembly
CDF’s ProBuilder tool allows contractors and facility managers to configure storefront door assemblies online. During configuration, ProBuilder displays only glass options that are compatible with the selected door type, frame, and fire rating. ProBuilder provides instant pricing and verifies that the complete assembly meets the specified fire rating and code requirements.
For assistance selecting glass or specifying a storefront door assembly, call (855) 769-9895 or email sales@cdfdoors.com. CDF’s sales team is available Monday through Friday, 7:30 AM to 4:30 PM CT.
Frequently Asked Questions
What type of glass is used in commercial storefront doors?
Tempered glass is the standard glass type for commercial storefront doors. Tempered glass is approximately ten times stronger than standard annealed glass and breaks into small, rounded pebbles rather than sharp shards, qualifying it as safety glass under ANSI Z97.1 and CPSC 16 CFR 1201. For applications requiring additional performance, laminated glass provides impact resistance and security, while insulated glass units provide thermal performance for energy code compliance.
What is the difference between narrow stile, medium stile, and wide stile storefront doors?
The stile is the vertical framing member on each side of the door. Narrow stile doors (2-1/4” to 3”) maximize glass area but accept limited hardware. Medium stile doors (3-1/2” to 4-1/2”) balance glass area with broader hardware compatibility and are the most commonly specified type. Wide stile doors (5” and wider) accommodate the full range of commercial hardware including exit devices and are required for high-traffic and code-required exit locations.
Can storefront doors be fire-rated?
Standard aluminum storefront doors are not fire-rated. When a fire rating is required, the opening must use a hollow metal (steel) door and frame assembly with fire-rated glass. Fire-rated assemblies are available at 20-minute, 45-minute, 60-minute, 90-minute, and 3-hour (180-minute) levels. All components in a fire-rated assembly, including the door, frame, glass, and hardware, must carry matching fire labels.
What glass is required for a fire-rated door?
Fire-rated doors require glass that carries a fire rating equal to or greater than the door assembly rating. Acceptable fire-rated glass types include fire-rated ceramics, fire-rated laminated glass, and wired glass. Wired glass is restricted to non-impact locations by current building codes because it does not meet safety glazing standards. The maximum glass size decreases as the fire rating increases. Doors with 90-minute ratings are typically limited to 100 square inches of glass per lite, and 3-hour (180-minute) rated doors generally do not permit any glass.
When should I use a storefront door instead of a hollow metal door?
Use a storefront door when the opening is an exterior entrance or retail-facing facade, maximum glass visibility is the design intent, no fire rating is required, and the door integrates with an aluminum storefront or curtain wall system. Use a hollow metal door with a lite kit when the opening requires a fire rating, higher physical security is needed, or the door is in an interior corridor, stairwell, or other rated wall assembly.
What is tempered glass and why is it used in storefront doors?
Tempered glass is manufactured through extreme heating followed by rapid cooling, which increases its strength to approximately ten times that of standard annealed glass. When tempered glass breaks, it shatters into small, rounded pebbles without sharp edges, which is why it is classified as safety glass. Tempered glass is required by code in all glazing locations where human impact is possible, including doors, sidelites, and glass panels near floor level. It is the standard and most cost-effective glass type for non-fire-rated storefront door applications.
