May 6, 2014
COMMERCIAL : CODES & STANDARDS
While the first few editions of a new code tend to be extremely controversial, over time, some general consensus is reached. So it should not come as a surprise that the number of code-change proposals submitted for the 2015 International Green Construction Code is half that submitted for the 2012 first edition.
These proposals will be considered during the International Code Council Code Development Hearings at the Memphis Cook Convention Center, April 27 to May 3. At press time, the hearings had not yet taken place, and the proposals were not yet public. However, here is what I anticipate.
Discussions will likely include the status of Life Cycle Assessment in the IgCC and the various components that go into performing that type of analysis. Other discussions are likely to focus on the electives available to an adopting jurisdiction, potentially including limits on the size of a building for which prescriptive design for energy conservation can be used. The acoustical performance of the building envelope might also be up for discussion.
Also on the agenda will be discussion surrounding Chapter 6 of the IgCC, which addresses energy conservation. This discussion will include proposed changes to the prescriptive design provisions, as well as design based upon the Zero Energy Performance Index, or zEPI. Topics to be discussed will include dynamic glazing and shading devices on fenestration.
State code amendments
While the development of the 2015 IgCC proceeds this year, more widespread adoption of the 2012 I-Codes is occurring. Some jurisdictions have adopted the I-Codes with little or no amendment; other states have amended them quite extensively. Two states in the latter category are Florida and California.
Florida’s tendency to amend the International Codes during their adoption process is legendary, with either the Florida Building Commission or its Technical Advisory Committees holding meetings almost monthly.
Florida recently completed the adoption process for the 2012 International Codes, the result of which is the 2014 Florida Building Code. As with previous editions of the Florida Building Code, the amendments made to the International Codes are extensive.
Among the more significant amendments is revision of the design wind speed model used in the 2012 IRC from Allowable Stress Design to Strength Design. As a result of this amendment, both the 2014 Florida Building Code and 2014 Florida Residential Code will use Strength Design to determine the required design pressure rating for components of the building’s exterior envelope. This means that the required design pressure ratings from both the 2014 Florida Building Code and the 2014 Florida Residential Code will need to be multiplied by 0.6 for the purposes of comparison to the AAMA/WDMA/CSA 101/I.S.2/A440 label. The targeted implementation date for the 2014 Florida Building Codes is December 2014.
To some extent, it seems as though Florida and California compete with each other in regards to which can more extensively amend the model codes during adoption. The state of California amends the model codes they adopt, and then they allow local jurisdictions to make further amendments, as long as they do not weaken the California version of the model code.
California has completed its adoption process for the 2012 International Codes, resulting in the 2013 California Building Code. Previous editions of the California Building Code and California Residential Code were based upon the IBC and IRC. The 2013 editions of these codes became effective Jan. 1, 2014.
By far, the most significant California amendments to the 2012 International Codes are those made to the 2012 International Energy Conservation Code. California previously relied upon its own energy code and did not adopt the IECC.
The primary impact of the California amendments on fenestration is that one prescriptive U-factor or SHGC is applied throughout all or most of the state, rather than varying by climate zone. In many cases, the more stringent value from Climate Zone 3 or 4 is used. For example, the prescriptive maximum U-factor for residential fenestration is 0.32. This is consistent with the prescriptive maximum U-factor for residential fenestration in Climate Zone 4, in the 2012 IECC. But the prescriptive maximum residential SHGC for most of the state is 0.25. This is consistent with the prescriptive maximum SHGC for residential fenestration in Climate Zone 3 of the 2012 IECC.