Detached ADU in Scarborough - Design, Permits, Construction

Scarborough's slope toward the Bluffs is a design asset: on Guildwood and Cliffside lots the natural grade drop lets us build a legal walk-out basement suite at the front and still place a garden suite at the rear, producing two rentable units from one permit cycle. City of Toronto garden suite rules apply; Scarborough's wide lots also make basement secondary suites with separate walk-out entrances viable alongside a detached unit. Wide suburban lots with grade changes toward the Bluffs, frequently allowing a walk-out basement suite as well as a rear garden suite.

Lake-moderated winters in Scarborough - 118 cm of snow, -3.9°C average - give one of the longest build seasons in the region (April-November), which shortens the permit-to-occupancy timeline on detached adu.

A detached unit stands clear of the main house, so it carries its own foundation, its own service laterals and its own exit - the three cost centres that separate it from an interior conversion on the same Scarborough lot. We trench services across the yard and pour to 1.2 m before the ground closes; framing, envelope and interior finishing then run through the cold months without holding up occupancy. Detached is the highest per-square-foot form of the four, and also the only one that leaves the existing house untouched - no shared walls, no disruption to the occupants during construction.