The 2014 Florida Building Code is set to be adopted by mid-year of 2015 and with it comes serious changes to the energy code that will affect residential construction in Northeast Florida.
The current code, 2010 Florida Building Code, was based on the 2009 International Codes, and the 2014 Florida Building Code is based on the 2012 International Code, which increases energy-efficiency requirements 18 percent.
The biggest change relates to the air tightness of the building envelope. The 2010 code required a maximum of seven air changes per hour when tested with a blower door (see image), and compliance currently can be demonstrated by a blower door test or a visual inspection of the items in Table 402.2.2 of the energy code.
The 2014 code requires a maximum of five air changes per hour that can only be demonstrated with a blower door test on every house.
Due to the tighter building envelope, section R303.4 of the Residential Code requires whole-house mechanical ventilation for all dwelling units with fewer than five air changes per hour, which is now all dwellings per the 2014 air tightness requirements.
Whole-house mechanical ventilation is not a common occurrence in Northeast Florida construction, and it has its critics, proponents and multiple design methods. All the strategies have pros and cons and will take research by each builder and HVAC contractor to determine which strategy will be best for their homes.
There are two paths to energy code compliance: prescriptive and performance. Very few builders use the prescriptive path because it requires that all ducts be in conditioned space instead of the attic.
Most everyone uses the performance path and a computer program called Energy Gauge. This program runs a simulation of the proposed house’s energy use and compares it with the code requirements. This gives builders opportunities to make trade-offs to fit their budget and construction style.
For example, if you want ducts in attic space, you will have to add more insulation or increase the efficiency of your HVAC or water heating systems. The 2014 performance path will be about 18 percent more efficient.
Other code changes include the requirement that 75 percent of lighting fixtures must have high-efficacy lamps instead of 50 percent in the current code. Also, the prescriptive code now requires R-38 in the ceiling instead of R-30, and CMU exterior walls require R-4 interior insulation instead of R-6.
This is a summary of the major changes coming to the Northeast Florida market and many other changes need to be considered.
The E-Council, created in 2011 by NEFBA and JEA to educate and build a bridge between professionals and the community about economical, environmentally friendly practices, is planning more in-depth presentations on the energy code changes and mechanical ventilation in 2015, so check out our website, ecounciljax.org, for calendar updates.
You can also find a draft of the 2014 Florida Building Code at bit.ly/2014buildingcode.