knightbuilder

I am using version 11 and have searched for an answer. I did save as the file into a remodel file. I can't figure out how to layer the as built under the remodel. I watched a video on templates and tried but it didn't work. Maybe user error.

I am a new user and and put my as built in one file. I saved the as built as a remodel and made all my changes to where walls are and other modifications. Is there a way to overlay my remodel over my as built to see the changes? I have viewed a video that said that I was supposed to lock a layer set but I unfortunately didn't do that before I started my remodel modifications. Any help is extremely valuable as I really don't want to redo all the work I did? Thanks in advance.

I am trying to do an as built of an old salt box with a central fireplace with hearths on three sides into three adjacent rooms. I have utilized the fireplace tool but only have one hearth. Is there anyway to add hearths to fireplaces or do I have to design this custom?