January 2026 marks the fifth full year in our house at White Tree Farm. Here’s the energy use summary for 2025 like I did for 2024, 2023, 2022 and 2021.
To start, here’s the cooling and heating degree days per month for all five years:
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I continue to use 11 degrees C as the Heating Degree Days baseline and 22 degrees C for the Cooling Degree Days baseline. The HDD for 2024 was the highest for us yet (2248) while CDD was also the highest for us yet (170).
Here’s our total monthly energy usage :
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December 2025 was so cold that we pretty much exceeded the capacity of the heat pumps and put the radiant heating back on. This can also be seen in the detailed energy use breakdown:
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Energy Base Loads
For 2025, the base load for propane and electricity were calculated to be 20.7 kWh/d and 30.8 kWh/d respectively. These are in line with the previous years.
Annual Heating and Cooling Energy Demands
I could now sum up our annual heating and cooling usage for 2025 which were 12756 kWh and 1688 kWh respectively,
| Passivhaus Standard | PHI Low Energy Building Standard | The Birches @ WTF in 2024 | |
|---|---|---|---|
| Heating | 15 kWh/m2/a | 30 kWh/m2/a | 36.8 kWh/m2/a |
| Cooling | 15 kWh/m2/a | 15 kWh/m2/a | 4.9 kWh/m2/a |
The use of the radiant floor heating in December 2025 definitely moved us over the Low Energy Building Standard but it was necessary due to the cold, cold weather.