This fall, green-thumbed Torontonians might be planting their backyard tulip bulbs next to new foundations. Surging populations and concerns about housing affordability are prompting many North American cities to explore fresh approaches to urban density. Accessory dwelling units (ADUs) — secondary structures that share the same lots as existing homes — are one solution.

After first approving streamlined as-of-right development of laneway suites in 2018, Toronto is now allowing similarly straightforward garden suite approvals as the first tenet of the city’s Expanding Housing Options in Neighbourhoods initiative, which is dedicated to “missing middle” development options.