It would be nice if the game would highlight whatever area of your building is causing your people not to build it. I have had several times where they wouldnt construct a building, but if I help them out by building ladders on say a support beam, they will start building again.
I’m glad to know that ladder engineering isn’t completely obsolete yet.
Seriously, though, this type of thing would be very nice to have. I know we’ve heard before that crafters will eventually let us know why they’re stuck, so it would make sense for builders to do the same.