The classic D&D module B2, "The Keep on the Borderlands", had an enticing section at the back called "Designing Floor Plans". In this section, it was recommended that interior floor plans be laid out for all the buildings within the walls of the Keep. A detailed map for one building, the Guild House, was included; the rest was left to the individual DM. Personally, I couldn't resist seeing what the inside of all those buildings looked like.
What I've done here is provide rough floor maps for every building in the Outer Bailey of the Keep, at a scale of 1 square = 5 feet. To do so I used "MapMaker Version 1.0", a tool which came with the 1996 D&D CD-ROM Core Rules. On the one hand, the tool is very coarse but it has some advantages. It's incredibly quick and easy to use - and once you're done you can even take a walkthrough in a full 3D viewer mode. Unfortunately, it doesn't support walls smaller than 5-feet wide; so I've done a bit of approximation, widening buildings until the interior floor space was about right. Also, chimneys may be shown as 5 feet to one side or the other on successive floors. (If you wish, you can assume that interior squares are 4-feet wide, exterior squares are 3.33-feet wide, and ignore the width of interior walls.)