For almost three years now, the builder/artist Mark deJong has been transforming a Camp Washington three-floor, shotgun-style domicile into the Swing House, a large-scale art installation in which the interior has been almost completely opened up — no stairs, no floors, no rooms with walls. But the center attraction is a new 30-foot-long swing with ropes secured to an iron beam across the ceiling. You can swing virtually from end to end, imagining the generations who have lived there previously. It’s a trip through time as well as space. DeJong has been inviting people for special occasions, but envisions a well-attended open house this summer when he’s finally finished. He also promises to get the word out about it through both social and traditional media; until then he’s letting the anticipation grow organically.