A glass porch leads from the original Boothbay Harbor cottage (see "Three-Season Special") to its master quarters. Rather than an addition, architect Rob Whitten created a separate suite, allowing the owners to heat a small space economically when they visit off-season. The master bath is comfortable and timeless, its painted plank walls a foil for the Carrera marble subway tile, countertops, and shower, with its pebbled floor.

The room is roughly a square with two white porcelain vessel sinks along one wall and an oval freestanding tub on another. A third leg contains the elegant shower and a pocket door opening to a windowed water closet.

Facing away from the water and closer to the road, the bath’s windows are high. Whitten added a big dormer with an operable window on top that funnels in sunlight and air, and the lighting scheme is a mix between contemporary and old-fashioned. “The fixtures are consistent with the original cottage, but are used in a modern way,” he says.

Nothing evokes coastal Maine like wood, but here the detailing is unexpected. The tongue-in-groove ceiling has a clean nickel gap, and the wall boarding has an extra groove, not exactly on center. “The 2-to-3 proportion of the board gives it more character and a little energy,” Whitten explains.

The new bath is separate but feels like part of the cottage. With iconic, well-loved buildings,“you have to be a good steward because they belong to everyone,” Whitten says. “We knew we’d be held accountable.”