Where do you live and what are the annual heating-degree days and cooling-degree days? What is the cost of propane, electricity and gas in your area? To analyze properly, you should not simply consider initial expense, but also operating expense and payback, which vary with the efficiency of the units you choose to use. And then there are the practical considerations: For example, what is the historical record for electrical power failures and duration? If loss of electrical power is common, you may need to plan for a generator and secondary emergency power circuitry for a partial or whole house support. Finally, what kind of radiant heating (water or electric) and to what extent? As you can see, there's lots more information that only you have that is necessary. Good luck on your project!

I
thought you should have a homeowner’s opinion.

I
would prefer natural gas heat. It’s a
warmer heat. The cost of natural gas has
gone down tremendously! We used to pay
$125/month for year-round service: furnace,
water heater, dryer. It went down to
$95, then $75, and now $54. We don’t
even have insulation in the majority of our walls! And natural gas IS clean.

Heating
oil is the dirty one. At the end of the
winter, walls need to be washed down. Of
course it’s not as dirty as my Grandma’s old house; it burned pure coal.

Propane
is clean, but it is tied into the price per barrel of crude oil; that is highly
volatile. (The price, not the oil…well
yes it is; it’s burned for heat. But you know what I mean…)

Electric
heat pump is only efficient down to 30 – 40 degrees. Lower than that requires supplemental heating…maybe
even a boost from extra electric resistors.
So your cost effectiveness depends on how many days lower than 30
degrees your location receives. With the push for solar and wind energy, they
will be making more efficient heat pumps for the colder climates.

Where
we are building, there is not natural gas.
A heat pump may be more efficient now, but we are going with geothermal (this
is a heat pump, but Delta values will make it run more efficiently) for the
long term. We bought the acre next door
so we can run the piping horizontally.

My
brother-in-law has an HVAC company; he became certified in geothermal when some
ICF builders wanted the highest efficiency houses. Once the houses were built, (Mid
south), the efficiency study determined that a heat pump would be far more
efficient than adding geothermal with its associated costs. They have tiny electric bills for their large
houses.

Our
former builder had geothermal in a totally cement house. Geothermal lends itself easily to in-floor
radiant heat. I don’t remember if he had
AC; he kept his house pretty warm. But
if you want AC also, you’ll need to run ductwork also.

We
don’t know what our energy costs will be in the future. It is the one cost we won’t have much control
over. The Supreme Court has already determined that the cost of cleaning up
existing power plants was not taken into consideration by the EPA. Going totally electric and relying mostly on
solar or wind power lays too much of a financial burden on the utility
companies…who will only transfer its cost to its customers. Dependence on oil
puts the power in the Middle East.

I
think the key is getting an energy efficient envelope of a house; that’s why
the heat pumps are more effective with the ICF:
higher R value. Spend more money on your windows, doors, insulation and
walls. THAT’s where your biggest savings
will come from.

Where I am moving, natural gas won't be effectively affordable. No lines in the area.

I am building propane but using air-forced ductwork that can be converted to geothermal when I sell my current home. At that point, I am going geothermal and solar, with propane heat as a back up. (Oh and yes, for jollies, I'm putting in a propane generator and a wood-burning stove -- New England does have a fair share of power outages!)

Great replies but can not let the natural gas is clean comment go. I think the jury is still out on how clean it really is. It is likely responsible for setting people's drinking water on fire, ruining the livability of land, and turning many neighbors into enemies.

Is it cleaner than mountaintop removal mined coal combustion? Maybe. Is it cleaner than solar PV and conservation? Probably not.

Bri...my house is ten yrs old. We have geothermal. It is a fairly large home. We have five zones.

we love our geothermal and have not regretted it for a moment.

On average, geothermal works best south of the Mason-Dixon line. The frost line goes too deep in the northern tier of states such as Michigan, Wisconsin, Minnesota, etc and the soil is too cold in winter at 6 ft depth for effective geothermal. If natural gas is available, it is the lowest cost per BTU transferred to the house air.

I have geothermal and I believe the tax rebate runs out in 2016? We could not take the rebate until we got the CO on the house and moved in. Just check your timing and details before you calculate your $. BTW the Geo is fabulous! I went with the Hydronmodule because we wanted to do radiant heat in the basement floor. That puppy heats the whole 6500 sf house through the dead of last couple years - Pennsylvania winters. We have another Carrier unit for the second floor and honestly probably don't need it for heat - AC is like a freezer! Yes it cost an arm and a leg but my monthly bills are half our tiny 1700 SF farmhouse which has an electric HP.

There are truths and exceptions to Mr. Dandy's comment. Most of the industry prefers vertical, drilled wells for the ground loop so frost depth is not much of a concern. For cold climates, avoiding air-sourced backup resistance heating is the main appeal for GSHP.

As for BTU efficiency, that depends on many variables. Allison of Energy Vangaurd does a good job considering gas vs heat pump in The shocking truth about heat pumps.

Most of his blog assumes air-sourced heat pumps and GSHP tends to have higher COPs than air-sourced. GSHP can have 400-600% energy efficiency conversions which is much more efficient than the highest efficiency gas furnaces. Site vs source energy conversions muddy the picture but many feel that even with devalued site energy use of heat pumps versus source energy use of gas, heat pumps can be more efficient depending on the situations. Here's a GBA thread that touches on Air-source vs GSHP.

Thank you so much everyone for your comments! I am reading through all of them an truly appreciate all of the input. If it helps, our home is about 2,800 square feet with an unfinished (for now) basement. We're building in Central Ohio, so the temperatures definitely get chilly and stay chilly in the winter months. Though we have the space for horizontal loops, we would do vertical for efficiency. Thank you missmoo12 for the comment about checking to see when the tax credit ends--I didn't event consider it not counting before it's installed. Great point!

HI Bri - I am currently choosing between geothermal and natural gas. Curious to see what you ended up choosing for your home and why! Thanks in advance :D