ABOUT
This is a very small and simple mod that adds a settlement workbench AND an ENTIRELY new room to a small area next to DC's Mayors Office. It is not a full settlement, so no, you can't put settlers there. But you can still build whatever you want there.
HOW TO USE
To use, go to Kellogg's House, found on the left side of DC from The Entrance, You must first go near Valentine's Detective Agency and then walk up the ramp found against the north wall. Once you get to Kellogg's House follow the stairs up and you're there. You should be able to find and use the workbench as soon as you get there.
REQUIREMENTS
Fallout 4, Obviously!
Nothing else is required.
INSTALLATION
To install, use a mod manager of your choice. 
Or if you're weird and don't wanna do that, just put the file into the FO4 data folder located at:
C:/Program FIles(x86)/Steam/Steamapps/common/Fallout 4/Data.
CREDITS
Me, me, and Me!
If you would like to modify this modification in any way, please give me credit. And tell me, too, so I can take a look!

If you like the mod please consider endorsing!
MY OTHER MODS
Well, at least the good ones.
Diamond City Settlement - Custom DC - Now Version 2.0