RENOVATIONS
Kitchen, Bath and Interior Work in Mississauga
New washrooms, kitchens and wall changes, with plumbing and HVAC folded into one application.
◆ Permits across Mississauga
Building Permit Services Mississauga: ARUs, Fourplexes and Renovations
Mississauga homeowners, investors and business owners hire iPermit’s building permit services to take a plan through the City’s ePlans portal, starting with the zoning check and ending with the issued permit. Most of our Mississauga enquiries are about adding units to an existing house, and that is where a building permit consultant earns the fee, because the City’s rules for second, third and fourth units have changed more than once since 2023.
ARUs and Fourplexes on a Mississauga Lot
Mississauga lets a detached house, semi or townhouse add as many as two additional residential units (ARUs). They can go in the basement, a converted garage, an upper floor or an addition, and one of them can be a garden suite of one or two storeys, depending on the lot. Only one garden suite is allowed per lot, and it needs a clear hard-surfaced path for fire access.
Since December 2023, the city also permits fourplexes as of right on low-rise residential lots, and the rules split into two paths:
- Converting an existing house. The building must have legally existed on December 6, 2023, and all four units have to fit inside it. You cannot add on to make room for the fourth unit.
- Building a new fourplex. The zoning sets a minimum lot of 295 m² with 9.75 m of frontage (415 m² and 13.5 m on a corner), heights of 10.6 m with a sloped roof or 8.1 m with a flat one, and lets a new fourplex cover up to 10% more of the lot than the base 40%.
- The fourth unit grant. The City covers its own development charges and cash-in-lieu of parkland on a fourth unit, but only if the unit stays rental for at least 25 years, is never converted to a condominium, and an agreement is registered on title before the permit is issued. Region of Peel, GO Transit and school board charges still apply.
Which path fits depends on the lot, so we compare both before anything is drawn. Our guide to the second unit permit in Mississauga covers the basement suite route in detail, and our residential building permits list every project type we handle.
◆ Feasibility first
Approvals That Come Before a Mississauga Permit
Mississauga treats every property in the city as a site plan control area and then exempts certain types of development. Whether your project falls under an exemption is the first of several checks that decide the order of approvals, and the drawings are tested against Zoning By-law 0225-2007 for setbacks, height, coverage and parking at the same time.
A design that breaks a zoning rule goes to the Committee of Adjustment for a minor variance, and the permit waits until that decision is final. Lots near provincial highways can also need a Ministry of Transportation permit. A good building permit consultant in Mississauga catches these at the start, so they do not surface as examiner comments halfway through review.
Meadowvale, Port Credit and the 15 cm Tree Rule
Three local reviews add the most time to Mississauga files, and each one runs on its own calendar.
Heritage districts. Meadowvale Village, Ontario’s first heritage conservation district, and Old Port Credit Village both need a heritage permit for exterior changes, additions and new construction, as do individually designated properties. Applications go first to the district’s subcommittee and then to the Heritage Advisory Committee, which meet on fixed monthly deadlines, so missing a cut-off can cost a month.
Trees. Mississauga’s Private Tree Protection By-law applies to any tree 15 cm (6 in.) or more in diameter, including dead ones, a lower threshold than the 20 cm used in Vaughan or Markham. The permit costs $399.77, plus $139.72 for each extra healthy tree, and construction projects need an arborist report. The City has 30 business days to review, and every 15 cm of trunk removed has to be replaced with a native shade tree, backed by a security deposit.
Conservation land. Near the Credit River, Etobicoke Creek or their tributaries, Credit Valley Conservation or TRCA may need to sign off first, each with its own permit.
◆ Steps in Mississauga
Getting a Mississauga File Through Prescreen
Mississauga locks a file while it is in prescreen or review, so the package has to be right before it goes in. That makes the first two steps the ones that decide the timeline.
01
Assess
Property and heritage check
Check the permit history and whether the house is designated or inside Meadowvale Village or Old Port Credit Village.
Intake
02
Check
Zoning and site plan exemptions
Check the lot against Zoning By-law 0225-2007 and the site plan exemptions, and compare the ARU and fourplex paths where more units are the goal.
Feasibility
03
Prepare
Drawings and required forms
Produce the plans, add structural or mechanical design where needed, and gather every form Mississauga asks for with that project type.
Drawings
04
File
ePlans submission
Submit through ePlans with the $50 prescreen fee, then answer every examiner comment in one resubmission wherever possible, since resubmissions have no guaranteed review time.
Municipal
◆ Mississauga work by project
Other Mississauga Permit Services
Mississauga treats a garage conversion very differently from a deck. Start with the page closest to your plans.
SECOND UNITS
Mississauga Basement Units
New and existing basement units, with the permit fee refunded once inspections are passed and the unit added to the City’s second unit registry.
ADDITIONS
Home Additions in Mississauga
Additions tested against By-law 0225-2007 and the site plan exemption list before we draw them.
DECKS
Decks, Porches and Stairwells
Decks, porches and basement stairwells, including heritage review in Meadowvale Village or Old Port Credit Village.
GARAGES
Garages and Garage Conversions
Detached garages and garage conversions, including a conversion into an additional residential unit.
ZONING
ARU and Fourplex Feasibility
Which unit path your lot supports, ARU or fourplex, and whether a variance will be needed.
Mississauga Permit Fees and the ARU Refund
Mississauga prices most home permits by the square metre. Current 2026 figures, per the Building Division fee schedule:
Project | 2026 City fee |
New detached, semi or townhouse | $18.99 per m² |
Residential addition | $13.96 per m² |
Additional unit in an existing house | $11.33 per m², refunded |
Interior alteration | $6.84 per m² |
Finished basement | $5.64 per m² |
Deck, porch or basement stairwell | $244 each |
Minimum residential permit fee | $244 |
The ARU refund is the detail most owners miss. You pay the fee upfront, and the City mails the cheque back once construction is finished and the inspections are passed, and that applies to legalizing an existing unit too. Second and third units are also exempt from most municipal charges. Changes after the permit is issued are billed at $160 an hour. What we charge for drawings is quoted separately, after a look at the property.
Prescreen, Review and the Real Wait in Mississauga
Every application is prescreened first, which usually takes 7 to 10 business days. The review clock only starts after that, and the City publishes both its first-review targets and the average time to an issued permit.
Permit type | First review (business days) | Average to issue |
New house (detached, semi) | 10 | 13 weeks |
Residential alteration | 10 | 7 weeks |
Second unit | 15 | 10 weeks |
New non-residential | 20 | 12 weeks |
Non-residential alteration | 20 | 9 weeks |
The gap between those two columns is mostly resubmissions. They have no guaranteed review time, the City says each cycle can add two weeks or more, and you cannot upload anything or reply to comments while a file is in prescreen or review. A missing sheet means waiting for the comment, fixing it and going back in line. That is why our building permit application services in Mississauga focus on a complete package on day one, with drawings from a qualified designer.
A permit expediter Mississauga builders rely on is really measured by how few cycles a file needs. We answer every comment in one resubmission wherever possible, within the agreed scope. The City makes the final decision, and nobody can guarantee its timeline.
Starting a Mississauga Project?
Share the address and what you want to add or change, and we’ll check the ARU, fourplex and site plan rules for your lot.
◆ Why iPermit?
What to Ask a Mississauga Building Permit Company
If you are weighing up a building permit company in Mississauga, ask whether they check the site plan exemptions before design, who signs the drawings, and who will handle the examiner. Our Vaughan office has worked on Ontario permits since 2006, through the organization behind iPermit. In Mississauga we handled the Tiffany Residence, a plumbing permit for two new washrooms, and our commercial work covers tenant fit-outs and changes of use. We handle design and permit coordination within the agreed scope. Review, issuance and inspections are the City’s job.
◆ Mississauga FAQ
Second Unit Questions from Mississauga Owners
Most Mississauga permit questions we get are about second units: whether they have to be registered, what to do with one that was built without a permit, and how far a garden suite can go. Short answers follow.
Do I have to register a second unit in Mississauga?
Yes. Second units have to be registered with the City and meet the Building Code, Fire Code and zoning. Registration is free: you send proof of ownership, the building permit signed off by the City’s inspectors and the registration form, and the public registry is updated monthly.
Can I legalize a basement apartment built without a permit?
Yes, but the permit comes first. You apply for a building permit for the existing unit, bring it up to code, pass the inspections and then register it. The ARU fee refund applies to legalization as well.
Can a garden suite be two storeys?
It can, if the lot is large enough for the zoning to allow it. Only one garden suite is permitted per lot, and it counts as one of your two additional units.
Can I update my drawings while the City is reviewing them?
No. Changes have to wait until the City issues its comments. If your plans change mid-review, we fold the change into the resubmission so it only costs one cycle.