Hi, I'm guessing that you need to know the definition of "change" for a family law modification. You don't say whether the modification is for custody or child support, but we'll start with the definition for change for child custody. First read this article on our site - https://www.faldp.org/Child-Custody.html. You'll discover that there isn't one single definition but "substantial change" is a collection of changes that may affect any of the parties. Also certain things like the child is now older, is not by itself a substantial change -- we knew that was going to happen.
In child support the concept of substantial change is similar, but the specific changes are different. Child support deals with the financial aspects of raising children, so things like being laid off of work, or getting a raise may be substantial. The changes must be permanent (one year or more) and involuntary. Someone can't quit their job and then try to have their child support reduced.
As to whether moving from one house to another is what the court means by substantial change -- the best we can do is say -- it depends on other factors present in the situation.
