Calling forth a window into the dimensions you create the opportunity to forcibly egress a creature into a fall from height.

When cast, this spell creates a one-way dimensional window adjacent a creature you can see. On your turn anyone adjacent to the target can take a Reaction to attempt to Shove the target through the window. 

A creature that is so defenestrated falls from 30ft above their original position, landing prone and taking 3d6 bludgeoning damage from the fall.

When cast at higher levels the fall height is increased by 10ft per level of the spell slot used to cast, and the bludgeoning damage also increases by 1d6.