1st Energy Bill

Today, I received my 1st utility bill and my Energy Star documents for this prototype home. My HERS score for this prototype is 54. The HERS index is based on using a code based home for energy modeling purposes that starts at a score of 100. In order to achieve the Energy Star Certification, a newly built home needs to score an 85 or lower (better), which means that the new home, with a score of 85, is supposed to be 15% more energy efficient than the code based model home at 100. So in these basic terms, since my score is a 54, the math says that my prototype should be at least 46% more energy efficient. Because this index is making some very general assumptions, the HERS score/index is and should only be used as a basic comparison. The reason I say this is because of what my 1st utility bill actually is. As I've mentioned in previous posts, both the Energy Star rater and myself expect this home to exceed 60% in energy savings compared to an average non-certified code based home. Based on the REM software that Energy Star uses to calculate the HERS score/index, this prototype (all electric) is expected to use (based on current local kw/hr rates) $1133.00 per year in total utility costs. Divide this # by 12 months and I should average about $94 per month on my utiltiy bill. Although I recognize that a single monthly bill is not a really accurate comparison, it's a good place to start. My utility bill for the 1st month is $49.89. We can then assume that if the software was completely accurate and the 1st bill was for $94, then the code based model homes utility bill would be about $175. With a real utility bill of $49.89 and using the assumptions of the Energy Star software's code based model, this means that this prototype's 1st utility bill is 71% less than what a code based model home's utility bill might be for the 1st month. This is a very positive sign that this prototype is going to perform exceptionally well considering what the total cost was to build this home. I will be turning the ERV down to the low setting as it is recommended to run the ERV on high for at least the 1st month. I will also be turning the dehumidifier off intermittingly in the crawl space and monitor the moisture levels now that the crawlspace humidity level is stable. Changing the ERV to low and reducing the amount of time the dehumidifier is running should both reduce the electrical load. It will be interesting to see how this affects the next utility bill.