Chocochub Have you tried placing the build on another lot within the same game to see if the doors can be locked? Also, have you tried playing the lot for a while to see if the options on the doors come back over time so you can set them? Have you tried placing the lot, saving and quitting then reloading?
Another thing I have found that will reset things like this sometimes is to go to build. Using the move lot option in the upper middle of the screen, grab the lot and sort of move it back and forth or wiggle it and then drop it back in the same place.
Hope this helps.