Because when you have to go, you have to go. This 3-BR, 2-BA near Central Square in Cambridge (or, if you're being really specific, Area IV) appears to have an attic right above it; and in that attic there appears by the floorplan to be a lone, lonely toilet. Well, then. Otherwise, the 1,324-square-foot, renovated condo has a lot of natural light, stainless-steel appliances and a master suite with bath (so the attic one is definitely a plan B or C). Oh, and this being Cambridge, the build was "eco-friendly." Yours for $539,900.