What the IgCC Means for the U.S. Window Replacement Industry


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Considered to be the country’s first national green model code, the International Green Construction Code (IgCC) was created to provide a baseline for sustainable commercial building design and construction. California’s first-in-the-nation Green Building Standards Code was what laid the groundwork for this relatively new addition to the I-Code family back in 2010. Today, the IgCC has been adopted in Florida, North Carolina, Maryland, Rhode Island, Oregon, and a few other jurisdictions to varying degrees.

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The IgCC’s intent is to improve buildings’ energy efficiency and reduce waste not just during construction but also well into building occupancy. Long-term, it aims to make green building not just mainstream but the new standard practice. While the code doesn’t cover low-rise residential buildings, it will still have a tremendous impact on the window replacement industry in the form of:

#1 The mandatory use of energy-efficient windows in new and existing commercial buildings

The IgCC has often been compared to the LEED program, whose compliance requirements are adopted on a voluntary, project-to-project basis. By contrast, the IgCC sets mandatory requirements for all new and existing commercial buildings within the adopting jurisdiction.

The difference in approach doesn’t necessarily put LEED and the IgCC at odds with each other. If anything, they are complementary. Once adopted by a jurisdiction, the IgCC can provide a framework for more comprehensive voluntary rating systems.

That said, let’s put things in the context of the window replacement industry. The mandatory use of energy-efficient windows is most evident in the requirement that the majority of installed building components be ENERGY STAR®-qualified. Promoting ENERGY STAR®-qualified windows from “nice-to-have” to “must-have” is in itself a huge change.

Another case in point is the IgCC’s stricter daylighting requirements. For compliance, at least 25 percent of a building’s occupied square footage should be in a daylighting zone with automatic controls.

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#2 More rigid requirements for the prescriptive path for energy conservation

Buildings that take a prescriptive (rather than performance- or outcome-based) approach to energy conservation have limited design flexibility under the IgCC. This is because compliance depends on how many items a building can tick off of a predetermined checklist of performance values.

Examples of limitations set by the IgCC on windows include :

  • Maximum SHGC and U-factor values. The IgCC requires windows in commercial properties to have maximum SHGC and U-factor values that are 10 percent lower than those specified in the 2012 International Energy Conservation Code.
  • Minimum PF values for shading devices. In Climate Zones 1 to 5, windows on the west, south, and east must have permanently attached shading devices with a minimum Projection Factor (PF) of 0.50.
  • Maximum amount of glass. The IgCC sets a maximum allowable glass area of 40 percent of the gross wall area. This limit exists because the prescriptive path doesn’t offer architects and building designers alternate ways to offset the effects of larger windows.

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#3 The supersession of previously established energy performance requirements

The new limits set on SHGC, U-factor, and total window area supersede the requirements in the 2012 IECC and ANSI/ASHRAE/IES Standard 90.1. What’s more, the IgCC requires that buildings have an overall energy performance at least 30 percent better than the requirements set in the 2006 IECC.

Final Thoughts

For window replacement contractors, code changes are always a challenge. Despite this, we recognize the need for more sustainability in building and acknowledge that codes like the IgCC are exactly what we need to achieve this end.

Last year, more than 500 proposed changes to the 2012 IgCC were publicly discussed and voted on. As we await the official release of the 2015 IgCC, we look forward to helping more property owners achieve not just code compliance, but loftier and more future-friendly energy efficiency goals.



Author Bio:

Charlie Gindele is a window replacement contractor with more than 45 years of industry experience under his belt. As the owner of Renewal by Andersen of Orange County, he is well placed to mentor budding contractors from all over North America on everything related to window replacement. He enjoys learning about new window technologies and trends and often shares his industry insights on his blog.


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