What records explain additional dwelling units at a Niagara Falls home?

The City's page says that under Zoning By-law 79-200 a lot inside the urban area boundary, on municipal water and sewer, may have up to two additional dwelling units with a detached, semi-detached or townhouse dwelling, either two inside or attached to the home or one inside and one in a detached building, for a total of three dwelling units on the lot; a duplex may have one more unit inside or one detached. A rural lot on private services may have two with a detached dwelling. Each unit needs one parking space, which may be in tandem, and on-street parking does not count.

A unit in an accessory building sits at least 1.2 metres from the rear and interior side lot lines and is capped at 93 m² of lot coverage and, in the urban area, 6 metres in height. The page says units cannot be severed or sold separately from the main home and cannot be used as vacation rental units in residential zones, and that its guide is current as of April 2025. A permission in the zone does not make an existing basement apartment lawful; the City's building permit records are where that is answered.

• Additional Dwelling Units (Secondary Units): the City's page on Zoning By-law 79-200: number of units, parking, setbacks and height
• Additional Dwelling Units Information and Application Guide: the City's guide, current as of April 2025 (PDF)

Extra units allowed is in the free check as a summary of the City's rule, from our hand-kept table of city rules, and the full report reads the lot's zone where the City's zoning map is open data we can use; where it isn't, the report's line says where the City publishes it. Neither is confirmation that a particular unit holds a permit or may be occupied.

Free check: pick “Extra units allowed” See the sample report