Heating Costs For An Older Home
2026-04-11 09:29 - General
I have the good fortune to currently be living very inexpensively in a home that's been in the family for seventy years or so. An older, barely-post-war, home. I don't know for sure but I suspect that thermal insulation is minimal to nonexistent. In looking for my own more permanent home, concentrating on an at least slightly newer one, guessing that more insulation will be one of the things that implies, has been on my mind. But how much of an issue is that really?
Here's my actual natural gas usage from September 2024 through August 2025. (Actually, a 5 day moving average for a slightly less spiky graph.) You can clearly see that in May through September usage is both very low and very flat: this is just the hot water heater, stove/oven, and clothes dryer. This non-heating period averages 0.354 therms per day. We can also clearly see on the graph, starting gradually in October and lasting through April, a much higher usage over the winter, when the house is being heated. This year, the peak was on the 25th of January, 10.93 therms used in one day — almost exactly a non-heating-month's usage!
On my most recent bill natural gas cost $1.51 per therm. If I subtract the average non-heating daily usage, then sum each day's usage for the month, then factor in this dollar cost, I can find out my actual heating cost:
| Month | Therms | Dollars |
| October | 19.87 | $29.99 |
| November | 52.54 | $79.26 |
| December | 164.25 | $247.78 |
| January | 240.62 | $362.97 |
| February | 171.91 | $259.32 |
| March | 91.19 | $137.57 |
| April | 37.78 | $57.00 |
Or: $1,174 to heat this 1,300-ish square foot house for one season. From what I can look up pretty quickly, this isn't too far out from typical for the region. Perhaps I need to adjust my expectations. Either way, it's nice to have this one real, carefully gathered, data point. These 778 therms used compare to the 2025-2026 season (so far) at 768. Distributed differently month-to-month but very similar overall.
