I have a huge soft maple tree in my yard I plan to have cut down and then I was thinking of pushing the stump up out of the ground with a D6. The problem is the tree is only 5 feet from the corner of my house, what is the likelihood the root system is attached to foundation?

Good question, how old do think the tree is, and was the house there first, or visa versa?

I would suggest going as deep as you can with the tree itself, and don't bother trying to remove anything else. This way any roots will rot and be absorbed into the soil and you can cover over and plant grass seed, or anything you else you want to plant.

I agree with tickle. Take the D6 back and get yourself a large stump grinder.