We're building a 2,500 sq ft house with an unfinished basement on 5+ acres. Our builder suggested geothermal and we agreed. They started to dig vertical lines but, after three days, said there were too many problems. Initially, they were going to have 3 400 ft lines but then said they were going to dig 6 200 ft lines. Now we're told that we'll have to have horizonal lines. Could/should this have been avoided? I'm assuming that we were paying more for vertical (although I haven't seen an invoice). Should we get a discount since we're getting the cheaper horizontal lines? I appreciate your help!

Must have unstable ground....I have had horizontal and no issues....cheaper and more surface area...and if they do the depth correct shouldn't be an issue in my small mind.