When Colman and Richard Riddell bought a tiny house in the Georgetown neighborhood in Washington, D.C., they knew they were becoming the latest caretakers of a curious piece of history.

The 1,700-square-foot home began life in the 1850s as the carriage house and stables for the mansion next door. The red brick property, tucked beside a quiet alley, was converted into a two-story, three-bedroom residence in 1923. Over the past 90 years, residents have left clues behind: terra cotta religious tiles, red and green stained glass windows and two second-floor Juliet balconies that open into a double-height living room.

Colman, a designer, says all the different styles gave her creative license inside the house.

“You don’t feel obligated to honor any kind of covenant or any sort of design, since everyone along the way has left their mark,” she says. “It frees you up to do interesting things.”

Colman’s solution for a house big on charm but skimpy on space: Give each room a jolt of personality. Or as she calls it, “a big wow factor.”

She created comfortable spaces for her family of four with dramatic surprises throughout: Snakeskin print vinyl wallpaper on the kitchen walls and ceiling; an oversize pink wing chair in her daughter’s tiny bedroom; and an army of painted Chinese chests bought during a year living in Beijing. They add warmth and badly needed storage.

Look around and you’ll see her bold brush strokes everywhere: an antelope head from eBay, black-and-white awning stripe wallpaper in the powder room and, instead of flowers, a vase of kale on the bar.

Colman had used neutral colors for walls, furniture and floors in her old house, and went with the same plan. “I call my style neutral-with-artifacts,” she says.

Walls were painted Benjamin Moore Dove Wing and Farrow & Ball Charleston Gray. Cream and taupe sofas and chairs were regrouped.

The kitchen got a minor facelift when she painted wood cabinets white and replaced counters with marble. The eye candy is Visual Comfort’s Trillion crystal chandelier. The kids love the home’s quirky features. Elizabeth’s bedroom has a balcony with a window she can fling open onto the living room. “I love my balcony because I can look out and watch when my mom is having a party,” Elizabeth says.

The Riddells are leaving their own stamp. Colman is thinking about adding rustic beams to the living room. Son Kane, 12, is drawing ninja battles and skateboard logos on his bedroom walls that are coated with Benjamin Moore chalkboard paint.