The phone rang in my office at the Wentworth Institute of Technology. It was Bruce Irving, the producer of This Old House. "We need as-built drawings in Salem," he said, "and we can't pay you anything for them." "Sounds like fun!" I replied. "Maybe we can work it into one of our classes." Wentworth Institute, where I teach, is known as an architecture school that graduates students who not only know how to design buildings, but how buildings are put together. It's a tradition: both the father and grandfather of TOH executive producer Russell Morash were students here. But "as-builts"—architectural plans of a house drawn after it has been built—for an old house like the one in Salem are dirty work. In the summertime, make that hot, dirty work. Someone has to crawl around in unimaginable places with a tape measure and a notebook, documenting not only the overall dimensions of rooms and corridors, but the details of structure and woodwork too so that worn out parts can be replaced, new pieces will match old and the designing architect and contractors can fully understand what is being renovated. That's what my students and I did. Two phases of the as-built drawing process are pictured here. First, sketches are drawn by hand, on-site, and dimensions are written down as parts of the house are measured. Then, back in the studio, these sketches are transposed into a computer, and with a few keystrokes and mouse clicks the final base-drawings are generated. After that, everyone on the project knows just what they're starting with. That's how it worked in Salem, and that's how it should work on your old house, too.