[stevehull]

You are VERY smart to concentrate now on exterior styrofoam and insulation. Any energy saving mechanisms such as heat pumps are MULTIPLIED by your increase in insulation.

What I might do is spent your resources (money +time) on insulation now and research the water source heat pump this winter. I realize how badly you want to have that heat, but efforts spent on tightening up a structure by adding more insulation and cutting down in infiltration is by FAR the best money spent.

Only after that do the energy saving source of heat.

The worst thing we could do is advise you on starting a project in a house that can't save energy as it is too poorly insulated.

Does this make sense?

Steve