What is the test for a motion to vary a custody order?

In Gordon v. Goertz, 1996 CanLII 191 (SCC), [1996] S.C.J. No. 52 (S.C.C.) McLachlin J. (as she then was) stated at paragraphs 10, 11 and 13: 10 Before the court can consider the merits of the application for variation, it must be satisfied there has been a material change in the circumstances of the child since the last custody order was made. Section 17(5) provides that the court shall not vary a custody or access order absent a change in the "condition, means, needs or other circumstances of the child". Accordingly, if the applicant is unable to show the existence of a material change, the inquiry can go no farther... 11 The requirement of a material change in the situation of the child means that an application to vary custody cannot serve as an indirect route of appeal from the original custody order. The court cannot retry the case, substituting its discretion for that of the original judge; it must assume the correctness of the decision and consider only the change in circumstances since the order was issued ... ... 13 It follows that before entering on the merits of an application to vary a custody order the judge must be satisfied of: (1) a change in the condition, means, needs or circumstances of the child and/or the ability of the parents to meet the needs of the child; (2) which materially affects the child; and (3) which was either not foreseen or could not have been reasonably contemplated by the judge who made the initial order.

In McCullough v. McCullough, [2003] P.E.I.J. No. 66, DesRoches C.J. summarized “material change in circumstances” at paragraph 10 as follows: In the basic law of variation, the original order is presumed correct. The court may only vary the previous order if there is a material change in circumstances. The burden of identifying such change is on the party seeking variation. Changed circumstances alone will not warrant a variation of the existing support order. If there is no material change, the motion is to be dismissed. "Material" is defined as substantial, unforeseen, and continuing in nature. (See Mullin v. Mullin, [1993] P.E.I.J. No. 69).