Garden suites, laneway suites and basement suites, planned and permitted by one Ontario studio, built by licensed builders. Markham permits up to 3 units.
Markham permits up to three units, with a two-unit registration fee of $246 plus a fire inspection fee. A fourth unit is not currently permitted as of right.
The right type depends on your lot, access and budget. These are the main configurations to consider here.
Convert below-grade space into a private, code-compliant suite with its own entrance. The fastest, most cost-effective path to an income unit on most lots.
Typical estimate: $60K–$120K
A detached backyard home on its own footprint. Maximum privacy and rental appeal, with the highest value uplift of the standard types.
Typical estimate: $150K–$400K+
A suite built over a new or existing garage. Adds a private upper-level unit without giving up backyard space.
Typical estimate: $100K–$200K
Rules summarised from the official Markham municipal page and are subject to change. Always confirm current requirements for your address.
Read Markham's additional dwelling unit requirements directly from the municipality.
Markham official ADU pageEstimated monthly rent ranges for this market. Actual rent depends on size, finish, bedroom count, parking and timing.
Estimates based on CMHC and TRREB market data for this region. These are illustrative reference points, not guaranteed ADU rents. Run a full ROI projection.
Province-wide ranges by suite type. Your actual cost depends on size, finish, servicing and site conditions, confirmed after a feasibility review.
| Suite type | Estimated cost | Notes |
|---|---|---|
| Basement suite | $60K–$120K | Convert below-grade space into a private, code-compliant suite with its own entrance. The fastest, most cost-effective path to an income unit on most lots. |
| Garden suite | $150K–$400K+ | A detached backyard home on its own footprint. Maximum privacy and rental appeal, with the highest value uplift of the standard types. |
| Above-garage suite | $100K–$200K | A suite built over a new or existing garage. Adds a private upper-level unit without giving up backyard space. |
All figures are estimates for educational purposes only. A property-specific quote replaces these ranges with actuals.
A legal suite can generate steady rent and add meaningful property value: an estimated $120K–$450K uplift depending on type.
Keep family close with independence and privacy, and convert to a rental later if your plans change.
Markham permits up to 3 units, and gentle-density rental housing is in steady demand across the region.
Most projects run 6–14 months end-to-end, with municipal approval timelines the main variable.
A free 30-minute call to understand your goals, lot and budget.
A property-specific review confirming what is buildable in Markham and the likely budget envelope.
Our design partners prepare permit-ready drawings, then we submit and manage the building permit.
An independent licensed builder, under its own contract with you, builds the suite. We coordinate the schedule and inspections and keep you updated throughout.
Final inspections, occupancy and a tenant-ready or family-ready suite.
A feasibility review, pricing estimate, ROI snapshot, region guide, and a 30-minute ADU consultation, all free.
Request a free, property-specific feasibility review for your Markham address. A senior advisor reviews your details and replies within one business day.