Now that's what I'm talking about.

http://books.google.ca/book...22&f=false

http://books.google.ca/books?id=zPMyUYAXhY8C&pg=PA333&lpg=PA333&dq=heating+%22balance+point%22+-%22heat+pumps%22&source=bl&ots=TTeH573gYv&sig=C5UStoQY7QuGonj_R4nlWbFfFHs&hl=en&ei=0er2TNDwF5HCsAPKiJnfCw&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBoQ6AEwATgK#v=onepage&q=heating%20%22balance%20point%22%20-%22heat%20pumps%22&f=false

http://en.wikipedia.org/wiki/Heating_degree_day

Calculations using HDD have several problems. Heat requirements are not linear with temperature,^[2] and heavily insulated buildings have a lower "balance point". The amount of heating and cooling required depends on several factors besides outdoor temperature: How well insulated a particular building is, the amount of solar radiation reaching the interior of a house, the number of electrical appliances running (e.g. computers raise their surrounding temperature) the amount of wind outside, and individuals' opinions about what constitutes a comfortable indoor temperature. Another important factor is the amount of relative humidity indoors; this is important in determining how comfortable an individual will be. Other variables such as wind speed, precipitation, cloud cover, heat index, and snow cover can also alter a building's thermal response.

What's is your building's average heating balance point under typical use?

That is the measure of your success in designing an energy conserving building. Then add on the benefits of energy efficient water and climate management equipment.

OK I will bite. Zip code 06232
October average temp where I live 51.8°F I used the woodstove 1 evening in October average temp in the house 67
November average temp 41.7 I used the woodstove 14 times average of 6 hour burn time total consumption of wood so far is ~ 16 cubic ft. Assuming a 70% efficient woodstove that is 2.2 million btu’s used. average temp 65. I have been sick a lot so I am keeping the temps higher than normal. When the woodstove is burning temp in the house is in the low to mid 70°s.
I have worked hard to keep electrical usage in the house low. I average about 200 kwh/month. If 100% of that was converted to heat it would be about 0.7 mbtu/month.
As for myself, I am in the house an average of 12 hours per day, same with the dog. We are each good for around 400 btus per hour so 800 btu’s per hour total. So for the month, we add 0.23 mBTU to the structure.
Cooking is a hard thing to quantify, I use gas so there is added heat, however the range exhaust is on when I am cooking so much of the heat is lost
House has 2000 ft^2 of conditioned space (includes basement)

In Ct the average house uses 731 kwh/month of electricity. If I used that much, I would probably not need to run the woodstove in nov either.
Dec average temp 30.8 Probably will have to run the woodstove most evenings

I still haven’t turned on the thermostat so I have not used any propane for heating.

I think wood constitutes a fuel, and operating a wood burning appliance would constitute heating.

You have to look at the outside temperature at which you must supply heat with with the wood burning appliance, as the balance point.

Foaf,
I am well aware that burning wood qualifies as heating. That is why I carefully quantified the wood I burned and btu’s delivered vs average temp for the MONTH. Along with that, I listed the other contributing sources of BTU’s that were applicable. I am sure If I ran a few big flat screen TV’s, changed to all incandescent lights, got a few more dogs, etc. I could shift the point at which I needed to run the woodstove. On the other hand this is all excess heat in the summer that must be dealt with.
The point of what I wrote is that there is no good way to measure an ”ideal temp” that requires additional heat. There are too many contributing factors. Measuring over an entire heating season is a lot more valid.
Internal heat gains from solar energy make a huge difference day to day in the heat required, and a well insulated high mass house looses temperature very slowly so a single day is irrelevant
If you want to express heating degree days using a different set point say 50 deg or so to account for the effects of internal heat gain, that works also. Lots of people have done that.

I think it is a lot more relevant to measure the total energy used by the house vs HDD or (average monthly temps) if you want that to quantify improvements.