The Green Movement in home building started about 12 years ago. There are two main pillars to the Green Movement: (1) the use of sustainable, non-polluting, and renewable materials to construct a home; and (2) the installation of both passive and active energy saving components as part of the construction process.
This article deals with the second main pillar of the Green Movement, the energy saving component. The International Code Council has developed an International Energy Conservation Code (IECC) and it covers eight designated geographic climate zones in the United States. These zones range from mild coastal climates to severe regions along part of the Canadian border. Several states have more than one climate zone. The individual states have the option of adopting and amending the IECC, with the latest version written in 2012, and more and more states are doing so.
But here is where the practical camp splits off from the “feel good” camp. True, all of the code requirements of the 2012 IECC will save energy, but the question is “how much” and “over what period of time?”
Recently the Home Innovation Research Lab (an affiliate of the National Association of Home Builders) published a report entitled 2012 IECC Cost Effective Analysis. According to this report, it costs more than $7000 to build the same home under the 2012 IECC than it did under the 2006 IECC. For an industry that is just beginning to recover from the Great Recession, this cost is burdensome. Further, it defeats the overall housing replacement cycle because the more expensive housing becomes, it keeps future buyers from moving out of their current higher energy consuming houses.
To understand in greater detail what sections of the 2012 IECC would be economically impractical, let’s look further at some of the specific provisions in the Code. All figures here have been provided by the Home Innovative Research Lab.
• Insulating hot water pipes inside the house. Yes, it makes sense to insulate hot water piping that is in unconditioned (non- heated or cooled) areas such as the garage or unheated basement. However the cost to insulate the other hot water piping varies from $500 to $1000 for an average size house. The energy savings would be $5 to $9 per year. The cost recovery time may be as long as 200 years.
• Reduce the insulation requirement in Climate Zone 3. To go from R-13 to R-20 may sound like a good requirement, but the annual cost savings is only $50, and it will take 24 years to recover the extra $1200 cost.
• Reduce the wall insulation requirements in Climate Zone 6. The current Code calls for R-20 in the walls plus an R-5 continuous insulation like foamboard. The previous Code called for R-20 only, and to add R-5 would result in an additional cost of approximately $1,819 for the average house. The annual energy savings would be $33, and the cost recovery time would be 55 years.
• Reduce basement wall insulation requirements in Climate Zone 5 from R-15 to R-10 per the previous Code. The increased insulation will cost $590 for an average house and will save $7 per year. The estimated cost recovery time is 84 years.
While energy conservation and energy independence are fine concepts, our goal should be to get buyers into energy efficient homes they can afford.