About Large Missile Impact Level 'E'
ASTM publishes ASTM E1996, Standard Specification for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes.
This standard is referenced in both the IBC (International Building Code and FBC (Florida Building Code) which governs use throughout the US.
Florida is of particular note due to added code sections relating to use of different missile impact levels for various types of structures.
This article focuses on Missile Level ‘E’ – Enhanced Impact Missile Protection.
Missile Level E is defined in ASTM as glazing passing testing involving a 9lb 2 X 4 at 80 ft/sec in various configurations, then subject to cyclical loading testing.
Missile level E differs from the more typical missile level D in that the 9lb 2 X 4 is shot at 80 ft/sec for missile level E vs 50 ft/sec for missile level D.
Use Cases
Information specific to the use of Missile Level E can be found in the Florida Building Code as follows:
FBC 453.25.1: New Facilities
New educational facilities for school boards and Florida college boards, unless specifically exempted by the board with the written concurrence of the applicable local emergency management agency or the Florida Division of Emergency Management (DEM), shall have appropriate areas designed as enhanced hurricane protection areas (EHPAs) in compliance with this section.
Exception: Facilities located, or proposed to be located, in a Category A, B or C evacuation zone shall not be subject to these requirements.
The 2023 Florida Building Code (8th Edition) addresses enhanced missile impact Level E requirements primarily through adoption of ASTM E1996-17 standards, with specific applications tied to building risk categories—especially essential facilities. Key sections include:
HVHZ areas (High-Velocity Hurricane Zone: Miami-Dade and Broward Counties)
•Chapter 16 (Structural Design):
Section 1626.2.4 mandates impact testing protocols (TAS 201-94) for wind-borne debris protection. Level E is implicitly required for essential facilities via referenced standards like ASTM E1996-17.
•Chapter 24 (Glazing):
Section 2411.3.2.4.i specifies enhanced impact resistance for operable windows/doors in essential facilities, aligning with Level E criteria.
Non-HVHZ Areas
•Chapter 17 (Special Inspections and Tests):
Section 1709.5.1.3.i adopts ASTM E1996-17 for impact-resistant building envelopes, requiring Level E for essential facilities (e.g., hospitals, emergency centers).
Essential facilities (Risk Category IV) must use Level E protection per ASTM E1996-17 Section 6.2.1.1, integrated statewide via FBC’s wind-resistance provisions.asdf
ASTM 1996 6.2.1.1 Enhanced Protection (Essential Facilities)Buildings and other structures designated as essential facilities, including, but not limited to, hospitals; other health care facilities having emergency treatment facilities; jails and detention facilities; fire, rescue and police stations, and emergency vehicle garages; designated emergency shelters; communications centers and other facilities required for emergency response; power generating stations; other public utility facilities required in an emergency; and buildings and other structures having critical national defense functions.
Outside Florida
The International Building Codes address enhanced missile impact Level E primarily through adoption of ASTM E1996-17 standards, with specific applications tied to essential facilities and high-risk regions.
For more information on ASTM missile levels, see this article.
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Last Update: June 26, 2025