Triplex Roy-Laval

In 2011, the existing three-storey, brown-brick building on the site was deemed structurally unsound and was demolished. In its place, a new triplex was proposed with the principal entrances moved from Laval avenue to Roy street in order to take full advantage of the length of the lot and to place the apartments’ living and exterior spaces on the south-west façade of the building.

The principle factor influencing the design and development of the proposed volume was its position at the intersection of two roads – Roy street and Laval avenue. Located in the borough of Plateau Mont-Royal, this corner property is zoned in an area along Roy street where 100% of the lot can be developed according to the municipal by-laws.

The modulation of the building at the intersection is achieved with a 12 degree rotation of the ground floor that reveals views ‘around the bend’ so to speak and with the subtraction of the balconies from the volume on the upper two floors. The basement and first floor volume displacement produce a cantilever of the top two floors over Laval avenue and creates a triangular, covered entryway into the communal staircase.

The main vertical circulation/access to the units became the second most important volumetric element in the building. The staircase is inserted into a notch in the middle of the Roy elevation to reduce the impact of the large corner-lot volume and is clad in glass for natural lighting and to contrast with the brick. The communal staircase also features a large skylight which, in combination with the open-tread stair, allows light to penetrate down to the ground floor from above. The result is that of an indoor-outdoor experience as one moves up or down the staircase to access or exit the units.

The final volumetric modulation is the subtraction to the back of the building on the top floor in consideration of the natural-light impacts on the neighboring building and lot on Laval. This also creates a rooftop terrace for the top floor unit overlooking Roy street.

Project type

New construction, residential

Completion date



Alain Mousseau, structural engineer *^Alt and Agapi Architects, execution drawings architect of record

Photo credits

Steve Montpetit, Yousef Farasat


Plateau Mont-Royal