An in-ground geothermal heating and cooling system for a building is provided. The system can include a buried ground source heat pump, a heat exchanger, and a ground loop circuit buried to a depth below the regional frost line. The system can also include a buried ground source heat pump buried inside a building to be heated. The system can also include an in-building heat exchanger disposed in a building, and an evaporative loop running from the ground source heat pump to the in-building heat exchanger. A method for installing such an in-ground geothermal heating and cooling system is also provided.