Hi, this is Robert Naini, your Spray Foam Advisor.
Today I want to talk to you about building code compliance, specifically from an energy performance standpoint.
When you look at the IECC for the residential code and the IECC for Commercial Code, you have a couple of different options for energy code compliance.
The residential energy code has three methods of achieving energy code compliance and on the commercial side there are two methods for compliance.
The two paths on the commercial side are the same as the first two paths on the residential side, they kind of mirror each other, but on the residential side there is a third option to provide energy code compliance.
I’ll break down each of these code compliance methods to show you the options.
The method most people are familiar with is the prescriptive code compliance method. This is where we follow the black and white letter of the building code, where the builder follows a checklist for compliance, this is where the code identifies specific R-values for wall and attic insulation. This comes directly out of the codebook, and we put it into the building exactly as required by code to meet the Builder’s needs.
Has a builder or homeowner has ever called you and said I’m in climate zone 3 so I need a quote for R-13 in the walls and R-38 in the attic, this is what he’s talking about – he has been trained throughout his construction practices, based on his climate zone, that there’s a specific way to meet code compliance for energy purposes and the way to do it is by following the prescriptive guidelines in the code.
The second method for code compliance is the performance path. The building code allows for alternate methods of compliance if it performs equal to or better than the prescriptive code guidelines and it meets the intent of the code.
The performance path allows energy modeling analysis to be conducted to show that a structure’s design meets the intent of the building code and provides equivalent or better energy performance than the building code minimum structure.
Overall, this means the prescriptive path describes the minimum requirements for a code compliant structure for that year of the code and the performance path allows you to do energy modeling to show that a specific building, as designed and built, will outperform the minimum code structure with the prescriptive requirements, like R-13 in the walls and R-38 in the attic.
The performance path essentially allows trade offs for various energy efficient design and construction practices.
Both of these methods, the prescriptive method and the performance method, work for residential and commercial code compliance.
The third method is only in the residential energy code, and it is called the Energy Rating Index, or ERI.
The energy rating index allows you to compare the performance of your building with the performance of a code minimum building from a previous code, and you have to meet certain criteria, specifically you have to be about 45 to 55 percent more energy efficient than the code minimum reference structure identified in the current version of the code.
If this sounds familiar, you might recognize that the Energy Rating Index uses the HERs rating process, comparing to a previous year’s code minimum, as a code compliance tool.
This recaps three methods of energy code compliance and hopefully gives you a better understanding of how this process works. This has been Robert Naini with Spray Foam Advisor, thanks for checking this out and catch me on some more videos.
