Early performance indicator

Comparing last December's gas bill to this year's, I got an early indicator regarding one measure of our new home's performance.  A year ago, we lived in a 1930, 2-story home that we had made many improvements to (including a new boiler and water heater, new double-pane windows, and more insulation).  Our new home is 10% larger than the old home, but comparing gas usage from 2016 to 2017 shows that we are currently using about 55% of the gas the the old home used.  Looking at weather data, it appears as if this same billing period last year was slightly warmer than the current year.

As time goes by, I look forward to comparing historical energy and water usage through comparisons of gas, water and electrical records.