With the arrival of their firstborn, Jasper, artist Kate Tucker and her husband, Tom Crago, made plans to decamp from their groovy South Melbourne digs and move to Fitzroy North, another inner suburb. The renewal of this formerly industrial neighborhood had brought boutiques, galleries, and cafes to the area—and with them, a sophisticated, artsy coterie.

The couple purchased a tumbledown turn-of-the-20th-century Edwardian, a former shared rental, in 2011. “The house had such charm,” Kate recalls. “Even in its run-down state, it had a beautiful feeling, and light.” Realizing the structure would need significant restoration, the family reached out to Emilio Fuscaldo and Imogen Pullar of Nest Architects to plan a remediation that would retain as much of the home’s original appeal as possible. “We lived here for a while before the renovation and learned that there was so much that was beautiful about the house that we should be careful not to mess with it any more than we had to,” Kate says.

After getting to know their new home, Kate and Tom, a video game executive, decided they wanted a modern extension that would complement the period architecture and its detailed fireplaces, timber floors, and ornate ceilings. Inside, this crossover of old and new is most overtly expressed where the original floorboards abut a new polished concrete slab.

Some contemporary remodeling—new joinery, cabinets, and partitions—of the original part of the house blurs the chronology and presages the dramatic floor juncture. “We wanted to honor the feel of the original house and create a smooth transition into an open, modern space at the back,” Kate says.

In one of the biggest changes to the structure, the original formal living room has been appropriated for the master bedroom, with a large sliding door closing it off from the front library and anteroom. Thanks to the bedroom’s tall bay windows—original to the house—the couple enjoy both glorious natural light and views out to the treetops of a nearby park.

The extension incorporated a fourth bedroom, a new bathroom and laundry, and a modern kitchen, dining, and living area that sits on the concrete floor. “In a big, open-plan addition like this, we didn’t want to lose the sense of delineation between the different areas,” Kate says as she holds her one-year-old daughter, Eleanor. In the extension, cabinetry partitions divide the space, giving the family a “sense of not being on top of each other,” and allowing them to use different areas for distinct functions.

“We love the junction between old and new. As long as everything has integrity, it seems to work.” —Kate Tucker, resident

The sloped ceiling, with its exposed steel beam, is finished in hardwood shiplap cladding. Echoing the cabinetry and maximizing space, a custom-made sofa in the living room is fixed snugly into an irregular corner and finished in burnished-tan leather upholstery. Like many of the surfaces—the concrete floor, the kitchen’s stainless-steel worktop—a marble slab on the center island reveals its wear and tear. “It’s the changing patina that excites us,” Fuscaldo says. “All the materials have a grain.”

The finished home—the renovation and its new outbuilding—is not fussy or delicate. It radiates creativity both in its design and in the way it’s inhabited. The palette of materials, the flow and proportions of spaces, and the dialogue between the formal Edwardian interior and the oblique lines of the extension together form a space that suits the many needs of its four residents.

“We have the ability to be connected to the street or totally secluded, within the same house,” Kate says. “It’s pretty special to be able to inhabit a space that changes with us.”