Molly Bachelor,
In the door/window selections settings under Tags and Categories there is a "Show on Renovation Filter" setting. These settings are necessary to illustrate things correctly in floor plan.
Set up your demo door/window to show on "Demolition Plan" and your New door/window to "Planned Status".
Now you wont get demo doors/windows markers showing up in your proposed plans and you can keep your markers in the demo plan.
Note that these new/demo elements will only show up in the renovation filter you select, even in 3D.
Hope this helps!
ArchiCAD 15 3267 USA FULL
Windows 7 Professional - 64-bit Operating System
Intel Xeon W3550, 8gb RAM, NVIDIA Quadro 600