Garden Suite Rear-Yard Context: 17 Theresa Ave
Daniel Du, Development Analytics
Generated 2026-09-22

== Method ==
We measure every low-rise residential lot within 500 m from parcel geometry in EPSG:2952. Lot depth is lot area divided by frontage, the planning convention. Frontage is the extent of the street-facing edge, measured along the street.

For each lot with a hosted building footprint we take the largest footprint as the main house, as the height studies do. We build a lot-aligned frame from the street-facing edge, the same construction the setback and building envelope studies use. The rear yard depth is the gap, measured along the depth axis of that frame, between the back of the main footprint and the lot line furthest from the street.

The subject is a corner lot. It fronts two streets. We take Theresa Ave, the addressed street, as the front, so the rear lot line is the line opposite Theresa Ave. We apply the same rule to the other 162 corner lots in the cohort and we keep them in the statistics. The median rear yard is 15.4 m for mid-block lots and 18.2 m for corner lots.

We exclude 9 lots where the largest footprint is a garage or where the footprint sits mostly outside the parcel. Those cases give a gap that does not belong to a house. 9 residential lots have no hosted footprint and appear neutral on the map.

The 7.5 m screen is an illustrative working threshold for a two-storey garden suite plus separation from the main house. It is not a by-law test. The garden suite regulations set their own setbacks, height limits and separation distances, and only a full zoning review applies them to a lot. The 10 m band marks lots that clear the screen with room to spare.

Committee precedent comes from Committee of Adjustment records within 500 m, filed from 2015 onward. We search the description field for 'garden suite', 'laneway suite' and 'ancillary', case-insensitive. The wider count adds 'accessory building', 'accessory structure' and 'accessory dwelling'. The open record is thin for this building type, so the counts are small and we report them as they are.

== Sources ==
- City of Toronto Open Data: Committee of Adjustment Applications (decision record for A0469/25NY), accessed September 2026.
- City of Toronto Open Data: Building Outlines with LiDAR heights, Municipal Parcels, Street Centrelines, Zoning By-law 569-2013 layers.

This is a retrospective demonstration on a decided public application. The Committee of Adjustment already decided this file, and it is a public record. Daniel Du was not retained on the matter. We prepared this analysis after the decision, as a work sample. It states no planning opinion.
