u/InsuranceScary8132

I’m working with a builder on a new home and I would like to have geothermal in-floor heating this was always the plan from the first phone call (and of course cooling from geothermal as well).
I have an in-town lot and the building footprint is such that the home will only be a few meters from the sidewalk (front yard is 3 to 4 meters deep x 20 meters wide) and 3-4 meters from the side lot line. Most of the land is at the back, which is at least twice the footprint of the planned house but slopes down fairly steeply to a river. The builder seems to have no idea how to integrate geothermal into the build and has not contacted any subs about this yet even though we are finished the design phase and almost at the point of signing a contract. They are saying now maybe there’s not enough room on the property. How much square footage do we really need to run a vertical system? Sounds like it’s a few deep 4” holes, so surely a 80 square meters along the front or side would do it?