Going though nearly three years and six different lairs, I can never seem to finish them.
Always missing resources for a silo or a few murals because I end up getting that "it's good enough" attitude and I declare it finished and never work on it again.
Today I actually finished one.... depending on what your definition of "finished" is. I'm actually surprised at it considering it's the one that took me the longest to build.
I would think "Finished" would mean nothing in the construction window, but as the lair was designed when the first wave of new murals came out, is it really finished?