Energy Codes

Background - Energy code compliance has been required by the commercial building codes for several years now, but only recently has it been enforced by code officials. The two prominent energy codes in the USA are the International Energy Code (IECC) and the ASHRAE Standard 90.1. State and locally adopted codes usually base their provisions on one of these references. By October 18, 2013, all States shall meet or exceed the ASHRAE 90.1-2010 energy efficiency provisions by determination of the Department of Energy (DOE).

Paths for compliance - The Energy codes have two paths to show compliance: A Prescriptive Path and a Performance Path. Both paths have advantages and disadvantages, and depending on the building use and energy goals, one may be more convenient than the other. Performance Path - This path usually requires a whole building energy modeling or the use of software to show compliance. In particular, there is a very helpful and user friendly software called COMCheck. This software was developed by the DOE to show energy code compliance to the building departments. It is available for free download at http://www.energycodes.gov/comcheck/download.stm . This software evaluates the total R-value or U-value of the building envelope (roof, walls, slab, doors, and windows) to determine if the building as a whole meets the energy code requirements. It conveniently prints out a certificate of compliance that you can hand out to the building official. Metal building assemblies are part of the drop down menus of COMCheck. Learning the use of this powerful and user-friendly tool gives a competitive advantage against alternative ways of compliance. On the other hand, whole building energy modeling is more complex and expensive, but is used on projects that have LEED certification as a sustainability goal. Prescriptive Path - The International Energy Conservation Code and ASHRAE 90.1 have two approaches to meet the prescriptive requirements: An R-value approach and a U-value approach.

The R-value approach is a cookie-cutter method based on a limited number of tested assemblies. Compliance is met if all the parameters shown in the tables are followed (i.e., R-19 insulation, standing seam roof, R-3.5 thermal blocks). The biggest disadvantage of the R-value path is that any deviation from the tabulated parameters will result in non-compliance. Alternatively, the U-value approach allows the use of any structure/insulation combination as long as the assembly does not exceed that maximum tabulated value. This allows builders to use different assemblies as long as they can demonstrate the U-value of the assembly. As a service to Star builders, the Green Initiative team can provide U-values on a case-by-case basis. State-specific Energy Code requirements – Some States like North Carolina and Florida have more stringent requirements than the IECC and ASHRAE. Star Building Systems has found insulation solutions that work for these States. Contact Star’s Green Initiative team for support. Conclusion - The final goal of the insulation requirements on the project specifications is generally to meet or exceed the energy code. Blindly following stringent prescriptive requirements may result in unnecessary costs. There is more than one way to meet the energy code. Star’s Green Initiative will provide Star Builders the necessary support to choose the most cost-effective option for each project.

Compliance Requirements Vary Depending on the Climate Zone