Indeed, the triple-barrel-vaulted house in the hilly Cleveland Park neighborhood of Washington, D.C., stands out among its pitched-roof neighbors. But one doesn’t anticipate much from it, dwarfed as it is by the stately two- and three-story residences on either side of it, as well as along the rest of the undulating block. A freestanding brick wall positioned 33 feet in front of the house reaches right about eye level, so that just the tops of the vaults are visible, further highlighting this plot’s peculiarity and leveling expectations of what lies beyond.