A Plywood Box Turns a 20th-Century Duplex Into a Multigenerational Home

MOA Architecture inserts a wood box into a Montreal duplex to make room for three generations of a growing family.

When young couple Leïla and Xavier decided to buy a house in Montreal, they envisioned a multigenerational home that could house Leïla’s mother as well as their own planned family. They purchased a duplex in the Rosemont-La Petite-Patrie neighborhood with two identical apartments (one over the other), and engaged architect Catherine Milanese of MOA Architecture to bring their dream to life.

Faced with this challenge, Milanese drastically reconfigured the floor plan and inserted a Nordic-inspired, plywood-clad mezzanine into the roof space of the second-floor apartment.

On the main floor of the second-story apartment, rustic oak flooring is paired with fir cladding, which unfolds into the staircase and walls of the "wood box" that contains the mezzanine level.

Before: The clients first imagined a home with a "granny flat" in the backyard, but they found this type of arrangement was not compatible with the typical lot in Montreal. The duplex they purchased instead had the same configuration on both levels. All of the interior finishes, the kitchen, the bathroom, and the windows were badly worn.

Leïla’s mother wanted to live on the ground floor apartment because the exterior staircase to the second floor—a classic feature of Montreal homes—can be dangerous in winter when icy. So, the couple decided to extend the second-story apartment to make it comfortable to live in with children in the near future. The new mezzanine level, which has access to a rooftop garden, provides office space for the couple today, and it will become the master bedroom when their planned-for children move into the two downstairs bedrooms.

The floors, walls, and ceiling of the mezzanine are all clad in clear-coated fir plywood panels. To respect Montreal city bylaws, the mezzanine was limited to 40% of the area of the level below.

"The house had not been renovated for a long time, and it desperately needed work on both levels," says Milanese. "We also had to completely rethink how the spaces were arranged, as the original layout blocked direct sunlight and access to the shared yard."

Before: The small and outdated kitchen and bathroom were originally located at the back of the home, where they blocked direct sunlight to the living spaces and impeded access to the backyard.

Before: The rooms on both floors were accessed from a central hallway.  The new configuration is a much more open plan.

MOA Architecture placed two bedrooms on the street side, which has a northern orientation, and created a central hub for the bathroom and laundry room. The living spaces are grouped together toward the rear of the apartment, where they benefit from the southern exposure and appealing views over the leafy backyard.

In order to comply with city bylaws, the 300-square-foot mezzanine had to be inserted into the existing roof space. "This led to the initial project concept: a built-in timber box within the existing dwelling," says Milanese. "The roof was cut in its center, and a new box was inserted in the open space."

The new mezzanine’s envelope responds to the climate in Quebec. It’s designed to offer the highest thermal insulation performance to effectively reduce heat loss during the wintertime.

The floors, walls, and ceiling of the mezzanine are all clad in clear-coated fir plywood panels. "Wood was used throughout the project for both structure and cladding," says Milanese. "It is used as a graphic, poetic, and emblematic material, and it’s a natural reference to Quebec’s Nordic culture." 

The mezzanine can easily be transformed into a guest room thanks to the sofa bed and the small adjoining bathroom. 

"Natural wood texture showing veins and knots is very much a part of our projects—it embodies Quebec’s architectural identity through the emotion and imagery it sparks, and it has the ability to poetically transport us to majestic forests and rustic cabins." —Catherine Milanese

The plumbing fixtures and the dark ceramic tile reflect the black color of the cabinets. Round recessed handles are visually refined yet allow the panels on the vanity unit to be easily opened.

The small bathroom on the mezzanine uses the same material palette as the kitchen. 

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The mezzanine boasts large windows, which frame a view over neighboring rooftops and trees, and a rooftop garden is accessed through large glazed doors. Natural light floods the interior through this south-facing glazing in summer months, and sunlight is reflected from snow into the interior during the winter. A dramatic steel awning frames the glazing to protect the interior from excessive heat in the summer.

The mezzanine has rooftop access through large, south-oriented glazed doors. A steel awning offers shade to the mezzanine level during summer months, and the inside face is clad with plywood to visually extend the interior space outward.

The main floor of the apartment is an L-shaped space, and the kitchen at its center features statement black quartz countertops that contrast with the lightness of the timber. The upper cabinets are crafted from the same fir plywood as the mezzanine level is clad in, and the lower cabinets are finished with black lacquer to create visual separation between the oak flooring and the fir plywood ceiling.

The kitchen countertops are black quartz, offering a strong visual contrast to the plywood. "Leïla and Xavier enjoy having friends over to sit at the kitchen island, which is the center of the space," says architect Catherine Milanese.

The cabinet handles in the kitchen are from Montreal-based Rainville Sangaré’s Bend collection.

A plywood-clad stair leads to the mezzanine, with an open black steel frame banister that allows a visual connection between the living space and the stairwell. "The banister had to be very open and light, so as not to visually reduce the living room space," says Milanese. "The whimsical design is the result of code-complying elements, and the desire to make the staircase as safe as possible for children. The resulting diagonal black steel elements bring a strong graphic effect to a very light structure."

Architect Catherine Milanese wanted to use a single material—fir plywood—for the stringer, the stairs, and the risers, visually integrating the stairway with the wood box that contains the mezzanine level.

Leïla works as an industrial designer, and it was a key part of the brief that the materials and details of the interior be carefully considered.

The project, excluding taxes and fees, cost CA$320,000 to build—CA$ 100,000 for the ground floor renovation, and CA$220,000 for the second level and mezzanine. "The budget was met, which is a rare feat in renovation projects," says Milanese. "The clients love their new home because it matches their personalities and lifestyle. I think that is a crucial quality in any residence."

Before and after second-floor plans of Wood Box by MOA Architecture show how the space has been reconfigured.

Mezzanine plan and section of Wood Box by MOA Architecture


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