For some people, the very thought of a renovation is enough to put the rest of life on hold. But not for Rebecca Robertson and Marco Pasanella, whose transformation of an aging New York City loft prompted a flurry of creative ventures, including a baby and a new business.

Robertson, deputy decorating editor at Martha Stewart Living, and Pasanella, a designer, moved to the southern tip of Manhattan five years ago. They found their haven on the top floor of an 1839 shipbuilders’ warehouse, in the heart of what was until recently the largest outdoor fish market in the country. They were so charmed by the location that they also turned a former fishmonger’s store, on the ground level, into a wine shop, Pasanella and Son Vintners. (The “and Son” is a tribute to 3-year-old Luca.)

Although raw interiors befitted the store, the wood-and-brick living quarters upstairs felt dark and drab despite its stretch of waterfront windows and its expansive size. As part of a complete overhaul, Robertson painted the original plank floors brilliant white using a marine deck coating to help reflect sun from a skylight. The new bead-board walls got the same glossy white treatment. “It all had to work together visually,” she says, “because when you walk in the door you immediately see everything, from the living room down to the office and playroom.”

The two bedrooms, a bathroom, and closets were sequestered behind closed doors, preserving an open floor plan for the rest of the space that has been surprisingly conducive to minding a toddler. “I don’t have to interrupt what I’m working on to check on Luca because I’m thinking, ‘Oh my God, is he doing something terrible?” says Pasanella, who designed much of their furniture. “The trade-off is that sometimes I’m not sure I want to see all his toys.”

While evidence of child’s play is out in the open, so too is the building’s rich seafaring history, as in the towering wooden beams in the central living area and a mammoth winch once used for hauling good between floors. Other signs of the loft’s heritage include brass light fixtures, rope-knot door pulls, and a fireplace clad in hand-painted delft tiles and witjes, which are white tiles with hints of pink, blue, and gray, made using a Dutch technique. “Neither of us wanted it to feel Ye Olde-y,” Robertson says with a laugh. “And we wanted to avoid a fishing-nets-equals-water type of look,” Pasanella adds.

The opportunity to play with the sheer volume of the space enticed the designing couple. “The place called for something dramatic,” Robertson says. “I knew it could handle a lot of pattern without feeling like too much at all.” So in came a panel of graphic wallpaper and a floral carpet in the living area. Pillows covered in ethnic block prints and colorful Scandinavian designs fill Luca’s bedroom. “The building is very forgiving in terms of letting you mix time periods together,” Robertson continues. “It’s not a Modernist slab where you have to be careful.”

The boldest move was also the most difficult. Robertson wanted to cover the bank of windows with curtains mounted on an industrial medical track, which is easy to maneuver and has no exposed hardware. But finding a pattern suitable for the 37 yards of drapery was a challenge. “We’re designers, so we know all the possibilities,” she says. “When it’s for a client a for a story, it’s clear. But not when it’s for you.” That year, friends of the couple received presents wrapped in fabric—all castoffs from the curtain auditions.

In the end, the home’s enchanting details stand out amid the sweeping scale. “We used to think that the big-deal purchase was going to make us happy,” Pasanella says. “But then Rebecca will put a palm frond in that vase my mother gave us, and it just looks like it was meant to be there.”