Turning Layers On/Off in Multiple View Port

As the title says, how do you get different layers showing in multiple viewports? I need to show 2 plans of a building layout on the same drawing but they need to have different layers on. When I switch a layer on/off or freeze, the layer goes from both viewports. I haven't done this before so any help would be appreciated.

While the viewport is active, open the Layer Manager and scroll over to the left. You will see a column called VP Freeze - use that to freeze layers in a single Viewport.