Use Alternative Energy Code for Commercial Buildings

Now that the State and Counties have adopted the new International Energy Conservation Code (IECC), specifiers and contractors need to be aware of alternatives that may be used instead of costly continuous foam insulation. For commercial construction, there are other options to use besides the IECC.

As the state and counties move toward adoption of the 2012 International Energy Conservation Code (IECC), there is concern about how to address the high cost of compliance due to new requirements for continuous foam insulation on steel framed exterior walls of commercial buildings.  The Hawaii Steel Alliance recommends that designers of commercial buildings, including hotels, apartments and other multifamily residential occupancies, follow the ASHRAE 90.1 standard entitled “Energy Standard for Buildings Except Low-Rise Residential.” 

Although the IECC is the base for the code that is used in Hawaii, the IECC has multiple compliance paths.  The ASHRAE 90.1 standard is referenced as an allowable method for compliance in lieu of following the IECC text.  The benefit of this option in Climate Zone 1, which is where Hawaii resides, is that, unlike the IECC insulation requirements, the ASHRAE 90.1 standard does not require continuous (foam) insulation on buildings. 

Chapter 5 of the 90.1 standard includes prescriptive tables for insulation, expressed in terms of R-values for insulation.  Specifically, Table 5.5.1 of the 2010 standard referenced in the IECC specifies R-13 cavity insulation for above-grade steel framed walls, without any exterior continuous insulation.  Members of the steel industry should cite this option in educating architects and others involved in building design to insure that the most cost-effective steel framed buildings are constructed.

For more information, contact HSA Codes Committee Chair Tim Waite.