Three videos of Board of Zoning Appeal cases from its Dec. 10 meeting have been posted on the “Cambridge Business Journal” YouTube page. The cases address adding a second story at 52 Union St.; building a two-story addition with a basement to the rear of an existing non-conforming house at 1 Wood St.; and modifications making room for an additional bathroom and deck at 69 Rindge Ave. Agendas for the meeting are here.