Tour a Fashion Insider’s Bright London Town House, Complete With an Evergreen Garden

She spent a year at the Sorbonne in Paris and then enrolled in the European Business School London, where she received her MBA. Did a business degree help coordinate contractors, builders, movers, and upholsterers? “Let’s just say it has come in handy many times,” she deadpans.

She met von Westenholz not long after moving to London two decades ago, and they were married in 2013. (Her wedding dress was Chanel Haute Couture, designed by Karl Lagerfeld.) They have two girls, Electra, seven, and Cleopatra, five, and a three-year-old son called Balthazar. “We thought they sounded like superhero names,” she says. “I knew when I was six that should I have a son he would be called Balthazar. Fritz took some convincing.”

Her daughters share a room and sleep in twin canopied beds that are hung with D. Porthault pink-clover-pattern fabric. The walls are covered with a mural designed to evoke Ludwig Bemelmans drawings. “The curtains are inspired by my childhood bedroom in Vienna, and I adored them growing up,” says Sieber, adding that Bemelmans was Austrian and they read his stories in his native German.

Built on a garden crescent in a row of similar historic houses, the home is surrounded by lush greenery both in the front and back, and filled with exceptional natural light. “It’s green as far as the eye can see, which is unusual for this part of London,” Sieber says. “We get woken up by birdsong in the morning.” The Garden of Ninfa, a sublime park built in a medieval town near Rome, has long been her garden fantasy. She commissioned Milan Hajsinek and, after a few conversations, gave him free rein. She only asked for evergreens. “It was essential to consider the months when we are in London to choose flowers that would bloom while we are at home.”

Sieber’s favorite room? The study, which she calls her refuge. “The view of the garden is so pretty—and no one apart from me is allowed inside!” But she strives to keep the whole house just as peaceful. “I constantly roam the house with a mission to declutter,” she confesses. “Mess can make me uneasy!”

This London town house story appears in AD’s November issue. Never miss an issue when you subscribe to AD.