What is the burden of proving a material change in circumstances?

In assessing whether there has been a material change in circumstances, the party seeking the change bears the burden of proof. Once that burden has been satisfied then the judge hearing the case must consider the case afresh. As noted at para. 47 of Gordon v. Goertz: The parent seeking the change bears the initial burden of demonstrating a material change of circumstances. Once that burden has been discharged, the judge must embark on a fresh inquiry in light of the change and all other relevant factors to determine the best interests of the child. There is neither need nor place to being this inquiry with a general rule that one of the parties will be unsuccessful if he or she fails to satisfy a specified burden of proof.

For both children, I have to determine whether there has been a change in circumstances within the meaning of Gordon v. Goertz. In both cases, I find that there has been a change in circumstances, requiring a reconsideration of the best interests of each child. My reasons for this conclusion are as follows.