Archi-docs (TM) seem to have become an ever-more popular film form, from My Architect to Sketches of Frank Gehry and Snakebit. Starting tonight, the National Buildings Museum in D.C. is hosting an entire film festival dedicated to the archi-doc. The festivities kick off tonight with a screening of Moving Midway, about one relatives plans to move the family's plantation home away from the sprawl encompassing it while at the same time selling the land to developers while others—including some former slaves—try to stop the move. On Monday, there is the debut of A Necessary Ruin, the work of LA-based filmmaker Evan Mather about the destruction of Fuller's Union Tank Car Dome, the largest free-span structure in the world at the time of its completion in 1958 with a diameter of 384 feet (trailer above). And a week from tonight, the festival closes with a screening of Megamall, which is about the rise of the film's titular developments across the country, with a particular focus on the Palisades Center in West Nyack. And before each film, a different short will be shown. Meanwhile, the fest has been excepting videos of "great green spaces," which you can watch on Vimeo or even submit your own.