“The house was a rambler that had rambled a little too far,” says architect Mark McInturff, who was called in to remedy the shortcomings of a sprawling, waterfront abode in Easton. Owners Hugh Panero and Mary Beth Durkin were empty-nesters who had decided to make their weekend getaway a full-time residence. They asked McInturff and his team to enhance and enlarge the dated house, located on a flat, sweeping lot.

“We figured, if we were going to give up the home in Chevy Chase where we raised our kids for 20 years, we wanted to make this house special,” explains Panero, the retired founder and CEO of XM Satellite Radio. “We’d had it for about eight years and besides adding a swimming pool, we had only made small changes.”

For the house to work as a permanent roost, Panero and his wife, an award-winning producer and documentary filmmaker who focuses on food journalism, both needed dedicated office space. They also wanted the existing rooms to be more functional, with a better connection to the outdoors. And in a departure from their former home’s Tudor style, the duo was looking for a contemporary sensibility this time around.

Panero and Durkin were drawn to McInturff, who is nationally known for his portfolio of dynamic, modern architecture. And, as Panero points out, “Mark has a home nearby that he’s renovated, so he knows the Chesapeake area.” For the same reason, the couple enlisted Darren Kornas of locally based thinkmakebuild for construction.

Since the house was already 200 feet long, McInturff opted not to expand it horizontally. Instead, he suggested building a tower that would stack two offices atop each other with a roof deck above. “Getting up 15, 25 or ultimately 40 feet above ground is a powerful way to experience the landscape of the Eastern Shore,” he explains. This restrained plan, he continues, would “make a big difference in one surgically located place” without the need for a whole-house renovation.

McInturff placed the tower above the home’s original foyer, which was torn down and replaced by a spacious, light-filled entry. On one side, a two-story staircase leads up to both offices; encased in drywall, it creates an airy, sculptural effect. “Making a stair that goes all the way up is a fun way to move around and to bring in light,” the architect observes. On the other side of the entry, he stacked closets in a column that can easily become an elevator shaft in the future.

The offices are duplicates of one another, each boasting a waterfront window wall, balcony and bath. On the third-floor landing, a door opposite Durkin’s office opens to an exterior, steel-and-cable stair that hugs the tower wall and leads to the roof deck. Installing the stairs was an engineering feat requiring a crane. “It was the thing to see in the neighborhood that day,” recalls Panero. Clad in durable Azek decking, the rooftop perch is a favorite spot for the owners, who enjoy cocktails and vistas there with friends.

The makeover also upgraded most of the existing interiors. Along with the new entry, the home’s center volume comprises the living room and kitchen; it’s flanked by the master bedroom on one side and on the other, a sunroom with a bedroom over it. During the renovation, the living room ceiling was raised and larger windows replaced smaller ones in this space and the nearby breakfast room and sunroom. The kitchen was remodeled by Chevy Chase-based Kitchen & Bath Studios to complement the rest of the house. “Once you open spaces up to one another, finishes like cabinetry have to be unified,” McInturff notes.

The master suite was reconfigured to include a new walk-in closet and an enlarged master bath; an existing guest bedroom in that wing now boasts an en suite bath. Wide-plank white-oak flooring throughout the house marries old and new. The same white-oak planks accent walls in the revamped living room.

In the backyard, a rundown deck spanning the width of the house was rebuilt with Azek planks. It connects the house to a big, stand-alone screened porch. McInturff took cues from the porch’s weathered shingles for the home’s exterior, which is now clad in cedar shakes that conjure a coastal feel and will fade over time to match the porch.

Seen from the front, the new tower is distinguished by soft lines and expanses of glass and shingle, while the back presents a more rigorously angled wall of windows and balconies. “The geometry of the house changes from different perspectives,” observes Panero. “The front is great—but in a house on the water, it’s always going to be about what’s in back.”

Renovation Architecture: Mark McInturff, FAIA, principal; Christopher Boyd, AIA, projectarchitect; Jeff McInturff, project designer, McInturff Architects, Bethesda, Maryland. Builder: Darren Kornas, thinkmakebuild, Easton, Maryland.