Secondary suites cost — Toronto & GTA
Computed from 639 classified Toronto building permits over the trailing 24 months — quartiles of declared permit values from the public record, never averages, vendor quotes or blog-post ranges.
Declared permit value
| Percentile | Declared value |
|---|---|
| P25 — smaller projects | $25K |
| Median | $47K |
| P75 — larger projects | $80K |
| Largest in window | $7.7M |
639 comparables · declared values from Toronto building permits, trailing 24 months.
Declared permit value per SF
| Percentile | Declared $/SF |
|---|---|
| P25 | $40 |
| Median | $63 |
| P75 | $117 |
402 permits with credible declared gross floor area. The denominator is the permit's declared GFA (all use classes summed); rates outside $20–$3,000/SF are discarded.
Size changes the number
| Size band | Projects | Declared $/SF · P25 | Median | P75 |
|---|---|---|---|---|
| < 5K SF | 384 | $40 | $60 | $114 |
| 5–10K SF | 16 | $92 | $132 | $158 |
What these numbers are — and aren't
Every figure is a declared construction value from a Toronto building permit, classified by GROUND's cost taxonomy (minimum 8 comparables per published category) over the trailing 24 months. Declared values can understate actual hard cost — awarded-contract benchmarks (tiers A/A+) arrive with award ingestion and will recalibrate these numbers where declarations run low. Full tier system and every category: GROUND Cost Index →
Getting quotes for this kind of work?
These benchmarks are the market-wide picture. For your project we'll read the comparables at your size and location, flag the permits you'll need, and check any quote against real awarded prices.
Residential addition & renovation · Office fit-out · Single detached & new houses · Underpinning & basement lowering · Laneway & garden suites · Restaurant fit-out · Multiplex (new) · Retail fit-out · Institutional alteration · Industrial & warehouse alteration · Medical & dental fit-out · Commercial interior (other) · New industrial building · Demolition