Hi Tim,

It really depends on how your builder is proposing to install the pool below grade. It also depends on the the frost zone you live in. If you live in areas that experience frost like we do In the southern region of Ontario you will require to go at least 4' below grade. Excavating, pouring a footing with re-bar, then forming a concrete wall on top of the footing or building a concrete block wall and filling it with concrete and rebar can cost between 300-350 a lnft, depending on thickness of re-bar strength of concrete. You are going to want to have a thick bedding of 3/4" clear under the pool to allow for drainage. Then on top of that you want to create a space to access the internal controls for maintenance and connections, you will need a removable access panel as well to cover the void. Short answer yes it can cost $20,000 easily if done correctly.