Originally posted by magilla666:

I put my forge against an outside wall, and knock down a section of that wall and place the bellows outside my house, then add walls around it and a roof over it.

You can also just make a lower floor below if you wanted for some of the items. Like for my kitchen building I usually bury the work bench and the forge.

Here is some pictures.
https://steamcommunity.com/sharedfiles/filedetails/?id=2783161996
https://steamcommunity.com/sharedfiles/filedetails/?id=2783162054

The forge and workbench are buried below in the center. Dug deep enough to place a full sized wall.