Detached ADU in Caledon - Design, Permits, Construction

Most of Caledon sits inside the Greenbelt or on the Niagara Escarpment, and almost every rural property runs on private well and septic. An accessory dwelling unit here starts with a septic loading calculation - the existing bed often cannot legally take another bedroom, and a new tile field, not the building, becomes the largest single line in the budget. Caledon permits additional residential units, but most rural properties require a septic capacity assessment and, on the escarpment, Niagara Escarpment Commission approval.

Rural acreages on private well and septic; Greenbelt and escarpment overlays cover a majority of the town's land area. North-GTA snowfall of 152 cm and -5.4°C winters give Caledon a May-October working season - foundations for detached adu go in before the ground closes, with interior finishing carried through the cold months.

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 Caledon 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.