Achieving higher building performance is pretty simple if you're retrofitting from a fossil fuel to a geothermal system. At best a fossil fuel system is 80-98 percent efficient, but a geothermal system is 400-500 percent efficient depending on the design of the system.
Proper design is the key to answering this question. Here is where the contractor can shine.
It's essential to properly size a geothermal unit. If it is a new construction or an existing home we do a site visit to see the home and to determine the best location for the loop field (vertical bore, horizontal...
I was asked to name the five benefits of geothermal — well, there are more than five, but for now I'll list the benefits that I feel are the top five. The first and the best benefit is the efficiency. With a properly designed geothermal system (emphasizing properly), efficiencies can be 400 to 500 percent.