Before heading to the job site, we pay a visit to the Air Force's AMARC, a vast collection of mothballed aircraft preserved in the Tucson desert for use as parts, for storage, or for destruction. As the Meigs' house, Mexican tile is going down in the courtyard, the new mesquite kitchen cabinets are in place, and we see the process of putting in poured concrete countertops, a first for This Old House. The library cabinet is the work of Tom Klijian, who has fashioned floor-to-ceiling bookshelves out of black walnut. Viewers take a tour of Tucson straw bale houses - one finished, one under construction with expert Matts Myhrman and builder John Woodin. Tucson is a national center of this environmentally friendly building technology. Back on site, a beautiful set of glass doors seals off the steam shower.