KatRad94 
Thanks for all of the files, really helpful!
I couldn't load the Lot in the save at all. My game crashed to desktop.
I saved the Tray files, started a brand new save and tried to place the Lot and again the game crashed. I tried placing from the map screen and on the empty Lot, Furnished and Unfurnshed but it just kept crashing.
I did manage to place the 10x10 "room" on my sim's Lot and didn't have any issues with it. I did notice that you've used a a massive amount of Starter Hedges shrunken down to create the gorgeous box hedging though.
Round: 42x4 = 168
Corner: 67x4 = 268
Big rectangle: 92x4 = 368
Small rectangle: 44x4 = 177
That's c. 981 hedge objects on a tiny 10x10 space and then the plants and trees on top.  Maybe the issues with the Lot is the sheer size of it and the amount of objects. It's a gorgeous build but maybe unplayable 😔