It looks ordinary, but this is the house of Wonder.
A Tudor-style home just off Avenue Road, it's got a stolid brick front with glossy black trim; it resembles its buttoned-down neighbours, except for some unruly shrubs and ivy. And the rainbow-hued kids' letters glued to the front door.

Inside, those hints of wildness break out everywhere. The house – home to designers Jason Halter and Anita Matusevics, their two children, and their firm Wonder Inc. – bursts with an unruly collection of modern design and art. Walk through the front door and you see white oak cabinets packed with artwork and a vintage Mac, walls hung with aerial photographs of Rome, an Ed Burtynsky image and a paintings by Jean-Michel Basquiat, classic modern furniture crowding the floor.
Underneath all the objects, the building itself is also unconventional. During a year-long reno with Kohn Shnier Architects, the couple didn't take the usual modernist approach to an older house. Instead of erasing all the walls, they've rearranged them, creating a home in which the purpose of each space is flexible and not entirely clear. “This place is meant to be multiprogrammed,” Mr. Halter says. “The house is a study; the house is a gallery; the house is a place for family artifacts.”

It's easy to see what he means. Beyond the front room, the main floor steps down into a big, windowed great room overlooking the backyard. Here, a profusion of beautiful things compete for your attention. “The kids' art as well as substantial art hangs out on the same wall,” Mr. Halter says, pointing to a drawing by the couple's five-year-old daughter and a Picasso etching. There are rambling houseplants, a Jason Miller antler chandelier and a marble-top table by Knoll. Against one wall, a keyboard is set with sheet music for the little girl and there's a classic Eames walnut stool instead of a piano bench.
On the second floor, their daughter and six-year-old son have their own rooms, plus a lounge to hang out in. But Mr. Halter says the children take advantage of the house's everything-goes feeling. “Here, the kids play everywhere; the living room is always full of toys or musical instruments,” he says. And in the attic is a wide-open master suite, centred on a shower – with a skylight on top. “This was one of the real indulgences of the house,” Mr. Halter says. “I wanted to shower in the rain.” But it also vents air out through the roof, helping cool the house (there is no air conditioner).

And though it feels freewheeling, the 2,800-square-foot building was shaped by a careful logic, architect Martin Kohn says. “Our main contribution was rearranging functions,” he says, “and eliminating a room” – the dining room. Instead, “they've got two multipurpose rooms: one more intimate and a bit more adult,” at the front, and “one big, bright and more kid-friendly.” The white galley kitchen, which is compact, looks over the back room and backyard “like a judges' dais.” And underneath the kitchen is a little slot where the kids can peek down into their parents' basement office. Home and office blend together.

But then, blurring boundaries is part of life for Mr. Halter and Ms. Matusevics, a pair of architecture-school grads who cut their teeth with Bruce Mau Design. Their company Wonder Inc. does graphic design for clients including top architecture firms KPMB and Diamond + Schmitt, and architectural design; over the years they've created signage, books and stationery, and a series of renovations, most recently a country inn and a live/work space for a noted Canadian artist.
Today Mr. Halter is an architect at Giannone Petricone Associates, while Ms. Matusevics runs Wonder. Then there is Mr. Halter's sideline as an art dealer, and Ms. Matusevics is designing a line of textiles with her sisters.
