This page will be continually added to, so check back for updates. For now it will serve as a running annotated bibliography.
The Massachusetts Cultural Resource Information System(MACRIS) contains survey forms and information for a lot of Carl Koch’s early work, including quite a bit on Techbuilt.
Stretching beyond North Carolina, George Smart and team are doing some amazing work. Their Library continues to grow and features many articles on Techbuilt and Carl Koch. For starters, look into the House + Home archive for some of the earliest articles that document the rise of Techbuilt: February 1953, August 1953 and February 1954.