I counted, and there are 14 houses in Sanctuary, 5 were destroyed leaving 9 in tact, and Bethesda thought it would be a good idea to only allow a door on two of those. Great Job guys.
Most houses only have 1 external door, but there is one other house that has two, so this mod adds 8 craftable doors. No need to use Build anywhere to fix this issue. No more need to use the floor mat glitch to fix this. Just add the doors to the houses, like any sane person would do.
Update: The 2.0 version of this mod does add doors on the inside of BOTH the player home, and the home where the workshop is (across the street from player home). This is just a test to see how people like these, and to see if people want me to add these to the other homes. For the inside doors, 2 frames were added for each door, so that you can hang whatever door you want from either side of the frame, or have two doors per frame if you like. To switch between them just spin the door (Right Mouse button for me) and watch where the handle goes. I placed both and then removed the one I did not like.
Disclaimer:
This mod will conflict with any other mod that modifies the Sanctuary "cells" or areas inside the game, so if you have a mod that cleans up sanctuary or something like that this mod will not work in conjunction with those mods. As a work around, you can disable those mods, and enable this mod, then hang your doors, then save, then disable this mod, and re-enable the other mod. The doors will stay where they are after this mod is removed, and still be fully functional, you would just loose the ability to change the door without re-enabling this mod. {Note that any containers added by the other mod should have their contents removed BEFORE disabling that mod, so that items are not lost. Forgot to mention this at first as most Sanctuary mods don't add containers.}
Bugs:
This bug is one I discovered while testing this mod, but is not caused by this mod. I found that the game will allow you to place an unlimited amount of doors in the door frames in Sanctuary. Don't believe me? Without this mod installed, go to your kitchen (player home before the war) and place a door in the empty frame (one of two Bethesda gives you), after placing the door, keep hitting the same button, to place additional doors. All doors will work, and just clip through each other, causing a hilarious delay for NPCs (looking at you Dogmeat).