Thanks again for all of your comments and ideas - the give and take of your posts provide us with great insights and ideas which will help us eventually choose the right system for our situation. Hubby found the DYI attachment interesting, but as an overworked aerospace engineer he just doesn't have the heart to tackle a DYI project of this size. (Over 1000 hours of overtime last year, similar amounts for the previous five years, and no end in sight! We joke this is our dream house money.) We did a major remodel of our own master bath four years ago, which included installing electric radiant heat, and it took two years, partially due to hubby's lack of time and partially due to the fact his engineer training meant every thing had to be perfect! Slows everything way down! :-) (Our current plan is to have the shell of the home, plumbing, and wiring done for us, and then we'll tackle as much of the interior work as we can ourselves, over time.) The JAGA site has some beautiful options (I love the scrolled radiator), but had my heart set on in-floor heat since this will be a small home with small rooms and would prefer to keep our wall space open. Just out of curiosity why is clay soil considered not good for geothermal? (I can't remember where I had read clay soils were preferred over dry, sandy soils.) I want to make sure I'm fairly well informed if and when we start to talk to geothermal installers. We may rule that option out entirely if it appears to be a problematic option for our property. Right now I'm really leaning towards the soapstone/masonry fireplace idea, and a combination of electric radiant in-floor heat (in tiled places where we might like heat year round, like the bathrooms) and hydronic radiant heat in rooms with wood flooring. Just need to figure out what will be the best way for us to heat and circulate that water. (If we use the fireplace to partially heat the water will we need a boiler or could a tankless or regular water heater handle the load?)

Thanks for taking the time to reply. Geoffrey_B: I agree, I plan on hiring heating and a\c contractor that I know as a consultant for all the brainwork and final connections etc. I also have a detailed list of parts and materials in the estimate as well as the sizing specs. The geothermal contractor is providing and installing the Waterfurnace Synergy 3D heat pump unit which handles both hydronic and forced air requirements. I believe I read the system operates at 120 degrees. Mike_home: to be honest with you I'm not sure. I'm not a huge fan of forced air heating for a few reasons 1st being I live in New York so the winters are long and heating is primary concern. We also have allergies and a hairy dog are another, so having dust and fir blowing about seemed to make the least sense (I know this will happen with AC). That left me with baseboard or radiant as choices. I chose radiant as it seemed more economical and I knew I liked the heated floor concept over the baseboard. The tax credit for the geothermal also applies to the heating system so that's helping offset the cost of the radiant floor. I will admit I could live without radiant floor on the second floor, but I'm not sure if this would complicate things.

stonitsch, it's OK, you ended up with the same numbers as those published on Electric Heat Cable company web sites. About 15 cents a day, more or less, give or take. And a double higher number if you double that. stonitsch, I wrote Watts too. Watts per square foot. When multiplied by total Square Footage, it gives you a total. Ask then, how much any heater of that size (X Watts) costs if it's left on all the time. Anyone gifted in multiplication can provide the answer. stonitsch, if you call the electric company, you could ask that same question too. This is the question to ask. Sometimes, asking what question to ask is the right thing to do. "If I have a X Watt consuming thingie left ON all the time, what does it cost?" is a good question to ask. Later, if you install a cable that is half that wattage, you can divide by half. It's a direct correlation. No need to ask anyone. - A thermostat lets you have a stronger than necessary heater being tempered by a reduced current. -- Whether the cables run on 240V or on 120V, it's all about Watts. Anything a 120V system can produce, can also be produced by a 240V system. (If 240V, the same amount of power is produced when the current is halved, which is what the thermostat does.) -- The price of Watts (price, in your area) multiplied by your consumption of Watts = the cost to you. -- Hth

Your HVAC expert who is designing the system should explain the requirements that the manufacturer has for their particular system. In general, in your situation, you will need lower temperature loops closer together rather than the traditional higher temperature loops further apart. The whole system has to be designed for the water temperature that you will need, as well as the PEX placement distance. Floor coverings also has to be taken into account in the plan. Rubber and carpet actually have insulative power (R values), and are not conductive to easily passing the heat through into the home. That has to be calculated when designing the system, and it will increase the lag time to temperature changes, which is already radiant's biggest drawback.