Perhaps it’s the temperate breeze rustling the gum trees or the charming older homes, but time seems languid in Annandale, one of Sydney’s oldest suburbs. Modest workers’ housing from the early 20th century nestle chummily together along streets scented with fragrant frangipani blooms. Dating from the early 1900s, Annandale cottages are known for their Victorian and Federation-era embellishments. But the one architects John Wilkin and Susanne Pini purchased in 2000 was botched by a heavy-handed 1970s renovation that stripped away its historic features, so the couple opted to treat the building like a blank slate. By keeping the existing shell intact while drawing from building traditions of the Far East, Wilkin and Pini added their own take on ornamentation.

As both work at fast-paced architectural firms for demanding clients, Wilkin and Pini cherish the slow pace of life and the sense of community the neighborhood affords. They spent five years transforming their long and narrow “semi”—Australian parlance for a single building split in two by a party wall —into a 1,200-square-foot Japanese-inspired retreat. “Our process was organic and evolving—we didn’t have a timeframe we were hell-bent on,” recalls Pini. “It was always much more important to get it right rather than just get it done. One of the luxuries of doing your own home is that you don’t have to approach things in an orderly programmed way, with everything thought out, priced, and reasoned.”

Little by little, room by room, the couple installed wooden cabinetry hand-built by Wilkin and a hired carpenter. The designers studied Japanese architecture while at university, and Pini once worked for a company that imported antique Japanese furniture, so the pair not only felt drawn to Eastern aesthetics (particularly Japanese design’s “compactness and lightness,” says Pini) but also to a slow, cumulative approach to renovation and woodworking. “Mick [the carpenter] would just come along on weekends when he was available, to work with John on whatever piece we had decided to do,” she explains. “There were often no drawings. We made sketches that matched the job to their skill level. Whatever work could be completed in two days was completed, and we left the rest to the next available weekend.”

For their young children, Tom and Ava, Wilkin and Pini designed two 116-square-foot bedrooms to resemble tansu chests, installing interlocking puzzles of built-in storage, clever shelving, and secret compartments. Crafted out of hoop pine plywood, the cabinetry makes use of every inch of the limited space. In Tom’s room, a new bay window faces onto the road. It doubles as a guest bed and a window seat with hidden storage space inside. Tom loves to scramble in and out of the window, as if playing in a tree house.

Wood is used extensively throughout the home, but despite the exquisite craftsmanship, it is never treated as precious. The bathroom and kitchen are clad entirely in plywood, from the cabinets and countertops to the edging around the bathtub and the front of the refrigerator. (All surfaces are sealed with water-based varnish.) The architects deliberately chose natural materials like wood and leather for their warm tones and texture, in spite of the fact that in wet, high-traffic areas the surfaces would quickly wear and darken. For Pini, weathering is a welcome part of the home’s design, a chance for the passing of time to be expressed. It’s a case study in wabi-sabi, the Japanese aesthetic precept in which beauty is beheld in the incomplete and unrefined. “We knew the limitations of plywood,but we like that it ages and stains,” she explains. “The wood becomes sumptuous and gains character with use.” According to Wilkin, the couple’s use of large, uncut plywood sheets is also a reference to traditional Japanese residential architecture, where the proportions of the rooms are based on a module the size of a tatami mat.

Wilkin and Pini chose cedar—lightweight, durable and relatively inexpensive—for the window frames. Built-in display ledges hide and showcase the family’s extensive collections of design, craft, and objets d’art. “We’ve been together for twenty years and have gathered lots of interesting, beautiful stuff,” says Pini. “So while renovating, we made sure to include storage, shelves, and window ledges that could double as display cases.” Rubber stamps sit on a sill in the bathroom. Italian soda bottles glow red in the kitchen. And in Tom’s bedroom, action figures stand at the ready, expertly lined up. “In small houses, you can’t have everything out at the same time,” Pini acknowledges. “Our collections are continually reorchestrated as the mood strikes.”

Pieces of the family’s collection work into the architecture in surprising ways. Slipped through a leather loop, an African cane from the 1930s becomes the bathroom door handle. The door slides open on wooden tracks built without traditional hardware and inspired by “the idea of shoji screens,” says Wilkin. “Because the door stays open most of the time and the walls don’t come all the way to the ceiling, we were able to break up the length of the corridor and bring in more light,” he adds.

Wilkin and Pini increased the size of their cottagewith a 270-square-foot addition at the rear of the original structure. A larger-scale riff on refined Japanese cabinetry, the double-height space accommodates the dining and living rooms as well as a mezzanine-level master bedroom and study.

In contrast to the rich textures of cedar and plywood used elsewhere, here, white plaster walls arch into a sloped ceiling. A steel-and-timber staircase seems to hover mid-air, dividing the living and dining areas. However spectral it seems, ultimately it is practical: The bottom steps serve as built-in seating for the large dining room table and slide to reveal storage space inside.

Tucked upstairs under the peaked roof, the master bedroom and study are a private escape. The balustrade is composed of various-size wooden dowels, a nod to the lightweight bamboo fences found in tea gardens. At certain moments in the day they cast reedy shadows against the living room walls.

Even in the new space, the passing of time is considered. “Our bedroom sits under the crown of a eucalyptus tree and the window frames views of the canopies surrounding the house,” notes Pini. “Shards of sunlight and shadow track the form of the room in the morning glow, each morning slightly different between the seasons.” The architects call their home the “Almost House” because it’s in a continuous state of “almost finished.” There is always one more little detail to design. Yet they’re in no rush to call the place complete. Says Wilkin: “The house evolves as we do. The mind never stops, so the project keeps going.”