I would like to suggest to any dev of this game that the building of buildings have a build order such that the lowest layer of the building first up to the highest layer and the hearthlings should wait until you have the resources to continue layers. This comes from the issue that I have been getting about hearthlings getting stuck on the top of buildings without being able to walk around because they built a free standing roof. FYI this is only an issue when I custom make buildings so it could be because of that.
Thank you for your time.