You have to navigate a winding dirt road and a steep set of moss-covered stairs if you want to enter the house perched on the top of a hill in rural Bucks County. And if you're not equipped with four-wheel-drive, a fast-flowing creek will mean you'll be parking your car at the neighbors' and taking a hike through the woods.

That commute draws no complaints from Paula Chamlee and Michael A. Smith, large-format professional photographers based in Tinicum Township. After exhibiting, teaching, and making photographs all over the world (Chamlee, 66, also paints and works in mixed-media and video), they always return to the treehouselike stucco dwelling situated at the top of the steep ravine, which houses studio, gallery, and living space in one.

Their shared vocation influences design here, from the gently curved entryway to the tree perfectly framed in the spare bedroom's window. Smith, 69, who bought 18 acres and began work on the house in 1977, envisioned "a cross between a loft and a cabin in the woods.

"I wanted it to be open and have the expansiveness of a loft, but also wanted it to have the intimacy and coziness of a cabin."

It was a 14-year construction process; the first four years, Smith lived in his truck.

"My kitchen drain was a garden hose with duct tape, and I had a two-burner hot plate and a toaster oven. Yet somehow I had a sit-down dinner for 14," he said.

When Orna Willis looks at the skeins of embroidery floss hanging from the wall in her home studio, it's not just a visual treat.

"Color has such a strong effect on me," Willis said, "that it gets mixed up in my senses until I don't know if I'm seeing it or hearing it or tasting it."

For Willis, an artist who creates intricate designs for her online fiber, fabric, and metal gallery and store, the pegboard is like grapes to a winemaker. "All I need to do is turn around and look at it, and it gets my creative juices flowing," she says.

So when Willis and her husband, Reid, both 53, moved with their 9-year-old daughter, Nina, from a McMansion in Ann Arbor, Mich., to a loft in Northern Liberties six years ago, color became her muse for the 2,950-square-foot blank canvas.

Today, the house is awash in artwork, much of it by Willis' 30-year-old daughter, Shiri Wolf, mixed with a few highlights by other artists including Andy Warhol and Piero Fornasetti. The main living room evokes warmth as well as space, with vignettes throughout: groupings of Scandinavian glassware, or large, prolifically growing terrariums. Willis' favorite design elements are those created of objects that she and her husband have accumulated in their travels to South Africa, Italy, Spain, Cambodia, and Israel, where Willis grew up. But nothing dictates the character of the rooms so much as the color.