Morphet wrote:

Finally finished building our new house, and want to plant the lemon
tree in the back yard. I want to plant it as close as possible
without killing the plumbing in the process. Does anybody have any
recommendations on how close I can plant it, or what a safe distance
woule be?

How big will it be?
5m away sounds good to me. To make sure it has plenty of sun and
watering it isn't wetting ground near house.

Have you planned your entire back yard?
It would be wiser before planting the lemon tree.