Everyone has a budget when building a house.  We still find ourselves “competing” with budgets for Ground Source Heat Pumps (or GSHP – otherwise known as “Geothermal”) – and have on more than one occasion lost business because someone was sold a $30,000 heat pump installation and they didn’t have enough money left over for our panels (which generally cost less than $20k installed for the average home).  And when you start to consider the VALUE associated with our product – a quieter more comfortable home, stronger and safer structure (with potentially lower insurance costs), tighter building envelope, faster dry-in, it is a much more difficult comparison to make and still choose GSHP, even when considering tax credits.

ANYWAY – enough talk - see this article from Green Building Advisor talking about Ground Source Heat Pumps.  It is interesting to note that in their efficiency calculations published by the manufacturers, they do not even have to consider the energy costs associated with the pumps or the fans!

http://www.greenbuildingadvisor.com/blogs/dept/musings/are-affordable-ground-source-heat-pumps-horizon

The conclusion is – most of the time they do not make sense, for especially with stick frame construction, most of the savings will be "leaking" out of your building envelope.  Focus on the building envelope, and you can get much greater returns from passive (not mechanical that can break down) equipment that costs much less….