You don't need a geothermal system to have reasonable heating & cooling bills. There were 2 options that i looked at and both were about the same cost and would have provided about the same efficiency. For both options, I selected high efficiency windows with e glass and argon gas as well as doors that have 3 point locks and tight seals all the way around. The first option was the geothermal system with blown cellulose insultation in the walls & attic. For the attic, I specified R38 insultation (about 11 inches of cellulose) - the minumum code in our area is R30. The second option was a spray foam insulation package and high efficiency heat pumps. In this option, the foam in the attic would have been sprayed onto the inner side of the roof so that all space inside the house would be insulated space, and the foam does the best job at blocking air from entering or leaving the home. With this option, an air exchanger system would be needed on the HVAC to bring in a fresh supply of conditioned air inside the house periodically. The spray foam cost is a lot more than the cellulose, but the heat pump HVAC system is a lot less than a geothermal heat pump system (mainly due to the extra cost of digging the pit or wells for the geothermal pipes). In the end, both of these approaches would have cost about the same. I chose GT because that is what I always wanted for my dream home, it was as simple as that. I know a heat pump system can work in a temperature zone like the Blue Ridge Mountains in the mid-atlantic region where I live, provided that the house is insulated AND air infiltration is minimized - well beyond minimum code requirements. You might look at buying a heat pump that has propane as the auxilairy heat (I believe they make these now). As mentioned above, if you live in a really harsh climate zone like Wisconsin - then a heat pump might not be the best choice. Spend extra money on the insulation package, put in the very best windows & doors, caulk the interior of the house - every nook and cranny, insulate under the foundation slab - do all the things you can to insulate and minimize air infiltration and then you can keep your heating and cooling bills down. I suggest looking at how new homes in Canada are built (check out Holmes on Homes) and build to their standards - the Canadians seem far ahead of the U.S. in building codes for energy efficient homes. Have you selected a builder yet? If not - make sure that you pick one who really knows how to build energy efficient homes. Don't ask them open ended questions - let them tell you all the steps they take and extra things they do to make the house as energy efficient as it can be. If you only insulate to minimum code and don't take the extra steps to minimize air infiltration - your monthly bills will be high no matter what HVAC power plant you use. These extra steps I mention cost money. But it is a pay me now or pay me later proposition. If you plan on living in the house for a long time, then it would be wise to make the investment now, when it is most cost effective to do so.

Very basic reply based on a very generic rule of thumb. For generic construction, you can figure a WAG of 30-35BTU/Hr/ft needed in your bath. Again, that's a generic WAG. If your house is older and the bathroom has exterior walls, windows, a poorly insulated crawlspace below and a cold attic above, you may need more. If your house it tight and well insulated, then you may need less. Thus, the 30-35BTU WAG. You say the bb is 1520BTU, for your 100sqft bathroom that equates to 15BTU. Most floor mats give off roughly 12-15BTU on average. Check the specs and you might find one with a higher rating. So if you add 100sqt of 15BTU mat to your bathroom, then you'll be at about 15.2 + 15 = 30.2BTU/Hr/sqft. That might be sufficient, but that's also using the output of the RFH mat as an actual heat source versus simply a source of under-foot comfort. And it's also using both sources, the BB and the RFH mat, at 100% of their rated outputs. If the RFH gets overstressed, CL&P may send you a thank you card along with your monthly bill. Again...a WAG.

This past winter has been the worse that we have seen. The coldest it got was around -30 but with the wind chill it was even colder. We may put in some type of heating system similar to my SILs. I'm not sure what it is she uses but it was cheap and would work good for an extra heat source incase it gets to cold. We do have a cousin that has a cathedral ceiling and radiant heating and they do fine with it. We will definitely get a nice boiler with 95%+. Reading a bit more online we will want one. The reasons we want the radiant heat is to help cut back on the heating costs during long winters and to not have dust blowing around. We have allergies and hate ducts. With the cathedral ceilings the radiant seems the best affordable option to help keep the heat near the floor and not blowing up to the ceilings. We will be installing reversible ceiling fans. Just wasn't sure what type of boiler to use since I figured with the cost of the fuel sources that propane would end up costing more. I have no clue how much it takes to run the boiler per day. Once we get a chance we are going to talk with a friend that does heating and plumbing and go over the boilers with him. I'd just like to look into stuff ahead of time so we will waste less time. He has installed the systems before but not that often due to the area being mostly poor.

Deb: Compare the cost of 1 million btu's of heat. I'll use your average costs. Oil at $2.73/gallon, 80% efficient furnace (your old oil furnace may be less efficient): (1,000,000 / 139,000 btu per gallon) x 2.73 / .8 = $24.55 Propane at $2.57 per gallon, 80% efficient furnace: (1,000,000 / 91,000 btu per gallon) x 2.57 / .8 = $35.30 Propane, 95% efficient furnace = $29.72 Heat pump w/electricity at $.15 per kw-hr delivered, C.O.P. = 3.25 at 35F ambient: (1,000,000 / 3414 btu per kw-hr) x .15 / 3.25 = $13.51 Straight electric resistance heat: = $13.51 x 3.25 = $43.90 The heat pump produces the same 1 million btu's of heat at more than half the cost of the 95% efficient propane furnace, and almost half the cost of the 80% oil furnace. Note that the cost of a heat pump defrost cycle is not included in the above calculation. As ambient temps increase from the 35F example, the C.O.P. increases, and the heat pump is even cheaper to run. The C.O.P. was taken from my 3-ton 14 SEER / 9 HSPF Goodman heat pump at 35F ambient. The heat pump needs auxiliary heat for when the ambient temps fall below the balance point of the home. That aux heat can be a propane furnace, oil furnace, or resistance electric strips. Using the heat pump as primary heating, with a gas/oil/propane furnace as auxiliary heat is called a dual-fuel system. These systems have a lot of advantages. Take care.