"For years I imagined that if my avocation and vocation were the same, I'd be in heaven," says Thomas Tait. He surveys the flourishing garden behind the cottage-style house he shares with his wife, Louise Hayes, and her two teenage sons, and adds, "Well, I'm pretty well here."

Tait is the sole proprietor of Gardener's Guild, earning his livelihood in residential garden design, construction and management. He works out of a rustic cedar cabin sequestered in the farthest reaches of the family's modest-size yard in American University Park. Sitting at his drafting table, barefoot and wearing a T-shirt and shorts, he explains, "I work for myself, I choose my clients, and I can say no."

It wasn't always so. For 10 years Tait was employed by a large commercial landscape firm and climbed its ladder. But he wanted to climb his own ladder, to "spend less time managing and get back to working with plants," he recalls. He retrenched to attend a two-year program in professional gardening at Longwood Gardens in Pennsylvania, after which he was ready to go out on his own. The logical choice was to work from home, to keep his overhead low. And so the cabin-studio was built.

It is a simple structure, inspired by a summer retreat on an island in New Hampshire's Lake Winnipesaukee, a place he and Hayes hold dear. True to the north woods aesthetic, the cabin -- designed by their architect friend Richard Leggin -- has a rough cedar interior, exposed framing and a wood stove. Well-worn rugs and faded patchwork quilts -- Hayes's touches -- soften the look of modern office equipment. The only architectural embellishment is a fish-scale shingle pattern under the front gable.

In the spirit of a cabin in the woods, the building is a retreat, too, a place to renew. Tait holes up to work, while Hayes, who has a job as a private school administrator, tucks into the leather easy chair to dream up plans for their next home project. ("We've always got something going," says Tait; currently they're planning to add a private space for Hayes onto the main house.) Under the eaves is a snug loft, "where we nap from time to time," says Tait. For the boys, the cabin is a place to hang out with friends.

The cabin and surrounding garden are of a piece. The couple designed the yard -- a standard 40-by-90-foot lot -- as a series of private zones. "We essentially started from scratch, except for this tree," says Tait, fingering the delicate branches of the silver maple that screens the cabin. Midway between the house and the cabin, boxwoods define a sitting area where Adirondack chairs painted a campy lime-green are clustered. Closer to the house is an outdoor dining area with a natural ceiling formed by a trellis woven with clematis and roses, from which is suspended a wrought-iron chandelier. An espaliered apple tree on one end and a water trough filled with floating water hyacinths on the other serve to frame the outdoor room.

The house's back porch has an old-shoe comfort, with vintage wicker furniture, its paint pleasantly peeling, rag rugs and a ceiling fan. The look is "pure Louise," says Tait. The porch looks out over the green lawn, serpentine flower beds and, beyond, a hint of the cabin. And from the porch, he says, "now it takes me 15 seconds to walk to work."