BuildRules/Mississauga/Basement apartment / secondary suite/Timeline

Mississauga, Ontario / Permit timeline

How long does a basement apartment / secondary suite permit take?

See the published review timing BuildRules has verified for a basement apartment / secondary suite project in Mississauga, Ontario, including conditions and official references.

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Focused project answerLast verified Oct 14, 2026
Published timing

For a complete application, Mississauga indicates that the first permit review may take 15 business days. Incomplete submissions and re-submissions can add two weeks or more; this is not a guaranteed permit-issuance timeline.

A review target is one stage of the project. Preparation, responses, issuance and inspections can add separate time.

Plan the stages separately

The published period is not the whole project.

For a complete application, Mississauga indicates that the first permit review may take 15 business days. Incomplete submissions and re-submissions can add two weeks or more; this is not a guaranteed permit-issuance timeline.

Official sources behind this page

PermitBuilding permit route applies

Mississauga lists basement apartments among permit-required projects and publishes an ARU conversion submission checklist.

Official sourceCity of MississaugaWhen a building permit is required · Permit-required and permit-exempt project examples
Verified2026-10-13Open proof
Conversion documentsDedicated checklist

The City requires project-specific forms and drawings when converting existing space into a second, third or fourth unit.

Official sourceCity of MississaugaAdditional residential unit conversions · Second, third and fourth unit conversion documents
Verified2026-10-01Open proof
RegistrationRequired for second units

Mississauga states that second units must meet code and zoning requirements and be registered with the City.

Official sourceCity of MississaugaRegistering a second unit · Free registration of a second unit; proof of ownership, signed-off permit and registration form
Verified2026-10-14Open proof
2026 ARU permit charges$11.33/m² plus minimum residential fee

Schedule B (2026) lists $11.33 per m² for an additional residential unit within an existing building plus the minimum residential fee; the Part 9 residential minimum is $244. Final amount depends on the permit scope and area confirmed by the City.

Official sourceCity of Mississauga2026 Classes of Permits and Fees, Building By-law 0236-2024 Schedule B · Schedule B (PDF p. 1): Part 9 residential $244 minimum and Group C additional residential unit within an existing building $11.33/m² plus minimum residential fee
Verified2026-10-14Open proof
ARU building-permit fee rebateRefunded after final inspections

The City says eligible building permit fees are automatically refunded after an ARU is constructed or legalized and all required inspections are complete. Expect other design, construction and property-specific charges.

Official sourceCity of MississaugaAdditional residential units: permit fee rebate and 2026 requirements · Building permit fee rebate, permit fees and charges, refund after all inspections, review time, zoning limitations
Verified2026-10-14Open proof
Second-unit registrationFree

The City charges no fee to register a second unit, but requires proof of ownership, signed-off building-permit evidence and a completed registration form.

Official sourceCity of MississaugaRegistering a second unit · Free registration of a second unit; proof of ownership, signed-off permit and registration form
Verified2026-10-14Open proof

Need the full project answer?

The main guide keeps the permit trigger, zoning questions, documents, fees, timing and next steps together.

Open the basement apartment / secondary suite guide