Florida Window Code Requirements
Florida property owners face a unique situation when it comes to their properties when compared to all other Americans. Proper hurricane protection when building or renovating a property in Florida is a necessity as local building codes dictate that exterior products be able to withstand various levels of storm intensity depending on where the home is located.
For Miami-Dade County, Broward County, the Keys and Palm Beaches, the entire service area falls within the strictest code requirements that were put into place following the catastrophic effects of Hurricane Andrew.
South Florida Building Code as it relates to Impact Windows
For a homeowner looking to install new windows in their home, they must elevate each opening with impact resistance using either impact resistant windows or a combination of non-impact resistant windows and impact resistant hurricane shutters. An impact window is one that has been tested by an approved product certification agency against high wind speeds and wind borne debris earning a specific level of impact resistance measured in terms of something called interior and exterior Design Pressures.
For a detailed description of a window product’s design pressure ratings, please check out our blog on impact window ratings.
The testing laboratory will assign a design pressure or dp rating based on the performance of the window or door with both positive and negative dp values corresponding to external and internal pressure the evaluation entity determines the unit can withstand. These dps are what a building department refers to when issuing a permit for a new construction or window replacement project in order to verify the proposed product adheres to local code requirements.
High Velocity Hurricane Zones (HVHZ)
Certain areas due to their proximity to the coast have more extreme weather conditions where the Florida building code requires even more stringent codes compared to the minimum statewide code. Hurricane window and door projects installed in these areas need to have performance characteristics that pass local code requirements established after the calculated wind speeds that category 5 hurricane Andrew demonstrated.
These areas are called Zone 5 High Velocity Hurricane Zones or HVHZ for short.
Hurricane Andrew Devastation Leads to Major Changes in Florida Building Codes
At 5 am, the morning of August 24th, Hurricane Andrew struck just south of downtown Miami. Wind speed at the time it hit was 165 mph (145 knots). The central pressure of Andrew registered at a minimum of 922 millibars (27.23 inches). The devastation was enormous and beyond belief – neighborhoods and buildings were leveled. This led to Florida building code changes meant to withstand these types of extreme storms.
Source: Nara Archives
Source: NOAA
The Florida Building Code For Impact Windows High-Velocity Hurricane Zone (HVHZ) Map
As mentioned, impact resistant products in HVHZ zones must be able to withstand higher wind speeds compared to other parts of Florida. Impact windows and doors approved in these areas are approved for use based on a given product’s design pressures.
In addition, these design pressures requirements will change based on either exposure c or exposure d requirements which refer to the opening’s location relative to the corner of the building’s structure.
Location determines impact resistance i.e. how much pressure and to what degree the unit must meet wind borne debris protection.
Typically, these hurricane windows and doors are made with heat strengthened or tempered glass and have a code appropriate anchorage system with the right amount of screws embedded a minimum distance within wood and/or concrete. Glass size, thickness and type determine its ability to resist adverse weather conditions.
The higher the square foot of coverage needed for an exterior opening, the thicker the impact glass needs to be but the lower the design pressures are for a given exterior windows opening.
Additional Benefits of Impact Products
Window replacement provides a number of additional benefits besides protection against hurricanes. These include lower energy costs, improved aesthetics, better resale value, security and insurance savings. To learn more, check out this blog about the benefits of impact windows and doors.
Additional Florida Window Code Requirements for Miami-Dade and Broward Counties
Some HVHZ zones have additional window and door requirements when it comes to construction projects. A local municipality might require specific windows and doors with specific minimum energy efficiency ratings. Some areas adhere to a “Turtle Code” which refers to reflectivity designed to protect wildlife.
Stronger Home Security
The bottom line is that an impact window and door upgrade makes a home more secure and a property owner have piece of mind that their home will be safe and secure during a storm. Building material industries are constantly innovating in order to improve their product to adhere to the increasing demands of specific regulations imposed on them by both local and state agencies.
Get a quote from ASP Windows and Doors today and get access to the products that are guaranteed to protect you, installed the correct way with a perfect customized solution for your home. Let Our Family Protect Yours!
