In my last blog I introduced the 1,000-Home Challenge, an innovative ACI initiative that is working to demonstrate the viability of reducing residential site energy use by 70% or more by enrolling 1,000 North American homes that either already qualify or are willing to make changes to do so. My family’s home is number five.

When I crunched the numbers, I found that our home already qualified, so in our case no additional work was needed. But 5 years previously I had taken some simple steps to substantially reduce and supplant our energy use.

My journey began when a Bay Area client approached me about installing solar PV on her home, which we had recently totally renovated. Since the home had been upgraded under California’s pioneering energy code I assumed its energy performance would be good. But when I sized a solar system to offset electricity use, I found that it would be too large to fit on the roof. I looked more closely at the home’s energy bill and found that it used, on average, 3,500 watts. Parsing that number, I was astounded, and tried in vain to count light bulbs and consider appliances to account for such high usage.

Determined to get to the bottom of it, I asked an electrician to help me measure the home’s electricity usage when the home was in a “sleep” state, that is, the way it would be when the occupants were away or asleep. We found that with everything off, the home was still consuming lots of electricity. Idling plug-load electronics alone could account for over 30% of the home’s overall usage, built-in electronics even more.

Although my client opted not to pursue system changes I recommended in a subsequent report, the experience taught me that there is great opportunity for sustainability upgrades with very modest lifestyle impacts. As a result I developed a snapshot audit method that allows a simplified model of how a home or small business uses electricity, and quantifies the results of making system changes. Using this audit method on my own home allowed me to identify and make a few simple changes, and reduce my electricity bill by 65%.

I’ll dive into more details on this simple audit method and where the energy savings were found in my final blog post in this three part series on the Thousand Home Challenge.