by: Christopher M. Cobb, Esq.
The 2010 edition of the Florida Building Code took effect March 15, 2012. Generally, the most significant changes were to wind load design and construction. Recent studies have confirmed what everyone in the state suspected: South Florida gets more hurricanes. Specifically, the most changes were those dealing with wind design in accordance with the new American Society of civil engineers (ASCE) pamphlet 7. The new standard creates a new wind map for the state and generally reduces design pressure across the entire state from 0 to 31 percent, depending on location. On the surface, it appears there is a substantial increase in wind speeds (ultimate wind speed); yet, the method of calculation has changed and the design pressure shows a decrease in most cases.
The 2010 Florida Building Code changes the wind-borne debris regions (WBDR). For south and central Florida the WBDR is increasing while in the north and northeast it is decreasing significantly. On the east coast from Volusia county to Duval the WBDR regulation only applies for the area within 1 mile of the coast. The same is true for the area from Pasco to the eastern 2/3 of Walton County. For central and south Florida the WBDR is increased and now will include all of the following counties: Miami-Dade, Broward, Monroe, Palm Beach, St. Lucie, Indian River, Brevard, Volusia, Pinellas, Manatee, Sarasota, Polk, Charlotte, Lee, Glades, Hardee, Hendry, Okeechobee, and Highlands. The result of these changes will mean there will be new areas with requirements for opening protection in accordance with Chapter 16 of the code. In summary fashion, the general changes are outlined below. They are:
• New wind speed maps and wind speed calculation method based upon the provisions of American Society of Civil Engineers publication known as ASCE 7-10.
• The current wind speed map will be replaced with three maps to be based on “Ultimate Design Wind Speeds".
• Each map will correspond to different “Risk Categories" based on the building use (i.e. Hospitals are more important than backyard storage shacks and will have a higher importance factor)
• The result of this change will be higher wind speeds for the county, however, in many cases the wind design pressures should remain about the same or even go down.
• The wind borne debris region requiring protection of openings will change.
In addition to the calculation of wind speed pressures, another major change appears in the energy code which is now its own volume of the code. The Commission has removed the energy provision form chapter 13 of the Building and chapter 11 of the Residential Volumes and placed them in the new volume of the code; the Florida Building Code, Energy Conservation. Users of the energy code will have to learn a new format for the document, as it is now formatted based on the International Energy Conservation Code format. Additionally, there are a number of other changes coming on the energy front. They are: (1) All duct sizing shall be in accordance with ACCA manual D; (2) All newly constructed single family dwelling will be required to provide a certificate of duct testing; (3) The testing must be accomplished in accordance with ASHRAE Standard 152; (4) All ducts and air handlers shall be either located in conditioned space or tested by a Class 1 Building energy rating System (BERS) rater to be “substantially leak free"; and, (5) Replacement A/C units must be sized in accordance with a nationally recognized standard and calculation submitted for permitting.
Lastly, with the significant “Green Building" movement in the construction industry, there was an effort made to include the International Green Building Code as an Appendix to both the Building Volume and the Residential Volume of the code. Such efforts were not successful. The general feeling was this document is not ready for inclusion into the 2010 Building Code. Ultimately, one would suspect such “green building" initiatives to make their way into subsequent code revisions.