There’s a disconnect between investing in conservation and investing in consumption. Rather than spending $35,000 on a GSHP or $20,000 on a radiant-floor heat-distribution system, it often makes more sense to put those dollars into energy conservation, passive solar design, and retrofits, like extra insulation, weatherstripping, and high-performance windows. For new construction, in cold climates, get the wall R-values to R-40 or higher. Then install high-performance windows with low-e coatings that provide R-5 or higher, and use air-sealing strategies to provide a tight envelope (1.5 air changes per hour at 50 pascals of pressure is recommended).
In an efficient house, having a high-performance envelope may eliminate the need for a central heating system. A VRF air-source heat pump or a wood heater may be able to meet all of your space-heating needs. It just doesn’t make sense to spend tens of thousands of dollars on a heating system to provide a few hundred dollars’ worth of heat per year.