Building Codes – Windows For Life

The Florida Building Code For Impact Windows

Understanding the Florida Building Code for Impact Windows
Florida Building Code | 6th Edition

For any property owner in South Florida, it is important to understand the Florida Building Code (FBC) and its requirements when planning some sort of renovation. The Florida Building Code was created in 2000 in response to Hurricane Andrew in 1992. Before then, counties and cities could create their building codes so long as they met state minimums. However, Hurricane Andrew demonstrated how lax codes or poor enforcement could endanger lives and property and create a statewide disaster. Municipalities can make amendments that are stricter than the statewide code, but no local code can be less than the current edition of the Florida Building Code.

Window and Door Replacement Requirements

The Florida Building Code is updated every 3 years to accommodate changes in climates, the housing market and building material industries. The newest version of the FBC will go into effect January of 2021, and it will be referred to as Florida Building Code 2020 (FBC 2020), as it will be created this year. FBC 2020 will be the 7th edition of the Florida Building Code.

When it comes to replacing or installing new windows and doors, the Florida Building Code has very specific requirements as to what is acceptable. According to FBC 2017, the version currently being enforced in our state, all glazed (window or glass) openings within a structure need to either be impact-resistant or use impact coverings, like accordion shutters or hurricane panels.

All window and door projects for both replacement and new construction need to be permitted with the local municipality. Therefore, no matter the type of product being installed, it must be proven to the building department when applying for the permit and during inspections that there is proper hurricane protection installed.

Since the Florida Building Code requires you to install either shutters or impact windows, homeowners must decide which protection is right for their property. Since both options are acceptable within FBC 2017, your decision will likely come down to other factors like how much do impact windows cost, how long does it take to get impact windows installed, will impact windows reduce my homeowners insurance, safety, labor, aesthetics or other benefits that you may want to consider. If you are trying to decide between installing hurricane shutters or impact windows, visit our hurricane shutters vs impact windows page for more information.

The Florida Building Code For Impact Windows High-Velocity Hurricane Zone (HVHZ) Map

South Florida is a unique place when it comes to residential building including windows and doors. While all of Florida must follow the Florida Building Code, areas throughout South Florida have even more stringent codes. One example of this is the High-Velocity Hurricane Zones or HVHZ. This is an area consisting of Palm Beach County, Broward County, Miami-Dade County, and Monroe County. These zones require stronger impact products to meet higher wind speeds of 170 mph to 200 mph.

Other areas in Florida require impact products or shutters that meet Wind-Borne Debris (WBD) certification. These products can be certified as impact-resistant but would not be authorized in the HVHZ zones unless they pass those tests as well.

How to Determine Your Required Design Pressure (DP)

Determining whether your home is in a HVHZ is the first step in deciding the required products needed for your project. The next step is deciding what is your buildings exposure. The height of the building and it’s proximity to large open areas like the ocean, determine the exposure. Our entire service area falls under either Exposure C or Exposure D. Exposure C is for any building under 60 feet tall and that is at least 1,000 ft away from any large open areas. Exposure D is for any building within 1,000 ft of any large open areas or any building that is over 60 ft tall, no matter the location. Certain buildings like schools and hospitals must meet Exposure D requirements no matter their size or location.

Finally, within your home there are 2 different zones (zone 4 and zone 5 ). This is because the corners of your house experience stronger forces from the wind during a storm. These zones are determined by the length of a single wall. Zone 5, which can require significantly higher negative design pressure ratings than zone 4 are any openings that are within 10% of the wall’s length from the corner. For example, for a wall measuring 20 ft, any opening within 2 ft of the corners would be considered zone 5 and need higher design pressures.

What Does This Mean for Your Window and Door Project?

So, what do these requirements mean for you? The FBC requirements for your building will determine what design pressures your new windows must meet. All these products must undergo both a missile test, which determines impact resistance, as well as a pressure test. The pressure test determines the product’s design pressures, both positive and negative. These design pressure ratings refer to how much pressure (measured in pounds per square foot) a window can withstand before it breaks.

If your house is required to have high DP’s, sometimes negative DP values for high-rises can be as high as -130 psf, you may become more limited in size or material types for your hurricane protection. To meet the changing demands of the Florida Building Code, manufacturers are constantly innovating to create larger and stronger products.

The Florida Building Code can be complicated to understand. If you are considering new impact windows and doors, we recommended that you speak with one of our professionals who understands all of these requirements and can explain them to you. To get a free consultation, just give us a call. We will be happy to answer all of your questions on our impact windows and doors.

The code states that replacement windows and doors shall meet the requirements in Table R402.1.2. PGT offers a wide range of products that meet the requirements in Table R402.1.2; however, before you order, we strongly recommend that you talk to your local building official about his/her plans for enforcement of this code.

Section 402.3.3 of the code states that up to 15 square feet of glazed fenestration per dwelling unit shall be permitted to be exempt from the U-factor and SHGC requirements in Table R402.1.2.

Yes, this code applies to all Florida Counties.

Condominium buildings with 3 stories or less are considered residential, and this code is applicable when replacing windows and doors in these types of structures. Condominium buildings with more than 3 stories are considered commercial, and should use the commercial provisions of the energy code when replacing windows and doors. Check with your local jurisdiction for specific requirements.

This approach is commonly used for residential and commercial new construction projects, as well as major retrofits, where insulation and wall systems are being changed.

PROTECTING THE BUILDING ENVELOPE UNDER THE 6TH EDITION (2017) FLORIDA BUILDING CODE

The 6th Edition (2017) Florida Building Code went into effect December 31, 2017. As with previous editions, the 6th Edition (2017) separates building types by Risk Categories into three wind speed maps. This brochure will focus on Risk Category II Buildings which include residential dwellings.

Requirements For Hurricane Protection Of Building Openings:

Specified on three different maps based on risk category.
Defines and incorporates the High Velocity Hurricane Zone (HVHZ) consisting of Miami-Dade and Broward Counties.
Defines areas of the state requiring wind-borne debris protection (see ASCE 7-10 wind map).
Areas within 1 mile of the mean high water line (the average between the high and low tide) where the wind speed is 130 mph or greater, or any location where the wind speed is 140 mph or greater.
Defines wind-borne debris protection.
Large-missile impact protection for all openings below 30 feet above grade.
Small-missile impact protection for openings from 30 feet above grade.

Exception: – outside HVHZ only:

Options for meeting the requirements:

Option 1: Plywood shutters may be used but they must be a minimum of 7/16-inch thick, precut with a code appropriate anchorage system permanently in place. They may not be used for openings exceeding a 44 inch span between lines of fasteners or a building mean roof height exceeding 33 feet. They cannot be used where wind speeds exceed 180 mph, Vult.
Option 2: Approved shutters (must be certified to meet either Miami-Dade protocols TAS 201, 202 and 203 or ASTM E1886 and E1996 impact tests) may be used except in HVHZ where only products tested to Miami-Dade protocols are permitted. Shutters may be of the roll-down, panel, accordion or other approved design type.
Option 3: Approved impact-resistant windows and doors (must be certified to meet either Miami-Dade TAS 201, 202 and 203 or ASTM E1886 and E1996 impact tests) may be used except in HVHZ where only products tested to Miami- Dade protocols are permitted.

Installation Requirements For All Windows And Doors:

When window buck (includes standard 1 x pressure treated buck) less than 1-1⁄2 inch thick is used, window attachment will require fastener penetration through the buck and into the substrate as recommended by the manufacturer.
When window buck 1-1⁄2 inch thick or thicker is used, the buck must be attached in a manner that transfers the load directly to the substrate. Windows must be attached to the buck.
The window buck must extend beyond the interior lip of the window to fully support the frame, unless otherwise tested.
Window and door assemblies shall be anchored in accordance with the published or written manufacturer’s recommendations to achieve the design pressure specified.
When window mulling, mulls shall demonstrate transfer of the load to the substrate. Generally speaking, this means that mulls will require anchorage to the substrate at each end as well as calculations (AAMA 450 using accepted engineering practices) or test reports substantiating the type and quantity of anchors.

Flashing at exterior window and door openings shall be installed in accordance with one or more of the following:

Requirements For Hurricane Protection Of Building Openings:

Exterior windows and glass doors shall be tested and approved by independent testing in a laboratory, and shall be labeled with an approved label identifying the manufacturer, performance characteristics and approved product certification agency, testing laboratory, evaluation entity or Miami-Dade Notice of Acceptance to indicate compliance with the requirements of one of the following specifications:

Glass strength: Determination of load resistance of glass for specified loads of products not tested and certified in accordance with Section 1709.5.1 shall be designed to comply with ASTM E 1300 in accordance with Section 2403.

Impact-resistant products may comply with ASTM E1886 and ASTM E1996 or Miami-Dade TAS 201, 202 and 203.

Glass Identification:

Exception:

For other than tempered glazing materials or laminated materials, the identification shall not be omitted unless approved and an affidavit is furnished by the glazing contractor certifying that each light is glazed in accordance with approved construction documents that comply with the provisions of Chapters 17 and 24.
Each pane of safety glazing installed in hazardous locations shall be identified by a label specifying the labeler, whether the manufacturer or installer, and the safety glazing standard with which it complies.
The safety glazing label shall be acid etched, sandblasted, ceramic fired or an embossed mark, or shall be of a type that once applied cannot be removed without being destroyed.
For other than tempered glass, labels are not required, provided the building official approves the use of a certificate, affidavit or other evidence confirming compliance with this code.
Tempered spandrel glass is permitted to be identified by the manufacturer with a removable paper label.

Required Information On Drawings/Floor-plan:

Ultimate design wind speed (Vult) and nominal design wind speed (Vasd) as determined in accordance with Section 1609.3.1
Risk Category from Table 1604.5 or Table 1.5-1 of ASCE 7 • Wind exposure: Where more than one wind exposure is utilized, the wind exposure and applicable wind direction shall be indicated
The applicable enclosure classifications and the internal pressure coefficient (if designing with ASCE 7)
Components and cladding: The design wind pressures in terms of psf (kN/m2) to be used for the selection of exterior component cladding materials not specifically designed by the registered design professional

When Using Or Specifying Wind-Borne Debris Protection, You Should Ask To See One Of The Following Certifications: