So Blurred glass material is impossible in Unreal Engine 4?

Nevermind figured it out. You need to set the material to “Before Tonemapping” down in the “post process material” settings.

This is a really nice basically free way to get controllable blur. The only problem with this technique is you will give up DOF elsewhere in the scene since this isn’t doing a separate pass its simply blending to a scene without the post process for outside the window.