Built from Desire Basements' completed GTA suites, the 2024 Ontario Building Code and the City of Richmond Hill's own rules. Every figure is sourced at the bottom of the page.
Every municipality applies the same Ontario Building Code and Fire Code, but the approval path differs from one city hall to the next. This is Richmond Hill's.
Richmond Hill requires a building permit before a basement is converted into an Additional Residential Unit, electrical work needs its own ESA permit, and the City does not run a suite registry; the closed permit and final inspection are your record. Established neighbourhoods like Mill Pond and Crosby mix mature homes where moisture control and ceiling height come first, while Bayview Hill, Jefferson and Oak Ridges offer newer two-storey homes with tall, dry, builder-grade basements. Under By-law 143-24, additional residential units are permitted in most zones that allow single-family homes, up to three additional units on a lot.
| Item | The Richmond Hill rule |
|---|---|
| Where a suite is allowed | Richmond Hill's By-law 143-24, passed December 11, 2024, permits up to three additional residential units on a lot, to a maximum of four dwelling units, in any zone that permits single detached, semi-detached and certain townhouse dwellings. |
| Permit | A building permit before construction, with staged inspections. The City also publishes pre-approved plans for a detached garden unit; a basement suite is an interior-alteration permit on the existing house. |
| Registration or licence | By-law 143-24 sets no separate registration step; the closed permit and final inspection are your record. |
| Fire and Building Code | The suite must meet the 2024 Ontario Building Code secondary-suite rules below and the Ontario Fire Code. Alarms, separation and egress are checked at inspection. |
| Fees | The applicable building permit fee, quoted by the City at application. It is inside every Desire quote. |
Permit drawings are prepared and stamped by a licensed structural engineer; we file the permit with the City of Richmond Hill, book every inspection and, where the City requires it, complete the registration. Nothing in that list lands on your desk.
These are the items the inspector checks, and the ones a cheap quote quietly leaves out. They come from the 2024 Ontario Building Code provisions for a secondary suite in an existing house.
| Requirement | Minimum | What it means on site |
|---|---|---|
| Ceiling height | 1.95 m (6 ft 5 in) | 1.85 m allowed under beams and ducts. Lower than that means underpinning or bench footing before anything else. |
| Egress window | 0.35 m² clear opening | No dimension under 380 mm; it must open without tools and stay open on its own. |
| Fire separation | 30 minutes | Between the suite and the rest of the house, floor assembly and shared walls, doors included. |
| Smoke alarms | Interconnected | Every smoke alarm in the house sounds together, hard-wired or wireless, so a fire in one unit wakes the other. |
| Carbon monoxide alarms | Adjacent to every sleeping area | Required where the house has a fuel-burning appliance or an attached garage; the alarm sits adjacent to every sleeping area in the suite. |
| Doors | 810 mm suite entrance | Bedroom doors at least 760 mm. Old 24-inch basement doors do not pass. |
| Separate entrance | Required | A walkout or side entrance, or a properly separated shared entry; a walkout runs $15,000 to $25,000 all in. |
The suite is priced like any other basement, then the Code items are added as lines you can see. Every basement is priced from the same quote sheet, line by line: a 1,000 sq ft basement with a three-piece bathroom comes to about $67,800 before HST, and the price per square foot falls as the basement grows because the permit, bin, breakers, stairs and bathroom cost the same at any size. Use the calculator to price yours.
| Line item | Typical cost |
|---|---|
| Finished space, 800 to 1,000 sq ft, three-piece bathroom included | $62,000 to $67,800 |
| Three-piece bathroom, already inside the line above | $11,700 on the quote sheet |
| Walkout or separate entrance, permits included | $15,000 to $25,000 |
| Kitchen, fire separation, alarms, egress window, permit and inspections | included in the suite quote |
| Full-perimeter underpinning, only where the ceiling is under 1.95 m | $60,000 to $120,000 |
| Typical purpose-built legal suite, no underpinning | $75,000 to $110,000+ |
Quote-sheet prices before HST; every project is quoted line by line after a free in-home consultation, with the written quote in your hands within 24 to 48 hours. Full breakdown in the 2026 GTA cost report.
Richmond Hill's houses run from 1960s bungalows near Yonge and Major Mackenzie with low ceilings to 1990s and 2000s two-storeys in Oak Ridges, Jefferson and Bayview Hill with full-height basements and walkout grades. The first group is where underpinning enters the conversation; the second is where a walkout entrance often already exists.
If you would rather see the build financed than paid in stages, our guide to financing a legal basement apartment sets out the options, and the rental income calculator models the suite in more detail than the sliders below.
GTA legal suites rent for $1,700 to $2,400 a month in 2026. Move the sliders to your build cost and the rent you expect, and the calculator shows gross payback and ten-year income. It is a planning tool, not a quote and not tax advice.
Gross figures before property tax, insurance, utilities, maintenance and income tax. Rent range from the Desire Basements 2026 cost report. Financing can spread the build into monthly payments the rent typically covers.
Design first: a free in-home visit, measurements, a ceiling-height check and a free 3D design of the suite. Then permit drawings, prepared and stamped by a licensed structural engineer and filed with the City of Richmond Hill while the design is finalised, so review time overlaps with planning instead of following it. Every quote is fixed and itemized before you sign and delivered within 24 to 48 hours of the visit. A legal suite takes about three months to build, with a written completion date on every contract backed by our $200 a day on-time guarantee, and the work carries a lifetime workmanship warranty.
Purpose-built legal suites in Desire Basements projects typically land between $75,000 and $110,000 or more, with underpinning ($60,000 to $120,000 full perimeter) extra where the ceiling is under the 1.95 metre minimum. The finished space, bathroom, separate entrance, kitchen, fire separation, alarms, egress window, permit and inspections are all inside that number.
Yes. A building permit from the City of Richmond Hill with staged inspections, and the suite must meet the 2024 Ontario Building Code and the Ontario Fire Code. Permit drawings are prepared and stamped by a licensed structural engineer; Desire Basements files the permit and manages every inspection.
GTA legal suites rent for $1,700 to $2,400 a month in 2026. At $2,000 a month, a $95,000 suite pays back its gross cost in about four years, before operating costs and tax.
1.95 metres (about 6 feet 5 inches) under the 2024 Ontario Building Code for a secondary suite in an existing house, with 1.85 metres allowed under beams and ducts. Below that, underpinning or bench footing is required first.
Yes. A walkout or side entrance, or a properly fire-separated shared entry. A new walkout entrance costs $15,000 to $25,000 all in, permits included.
Sources: City of Richmond Hill additional residential unit and second unit rules as published by the City; Ontario Building Code 2024, Part 11, secondary suites in existing houses; Desire Basements completed-project data, 2026 GTA Basement Cost Report. See also the Richmond Hill basement renovations and the rental income guide. Municipal rules change; confirm the current requirement with the City before you sign a lease.
Related reading: Legal basement requirements in Ontario
