Nobody wants to deal with building permits. You want to build the deck, finish the basement, add the suite. The permit is just a box to check on the way there.
But getting the permit wrong doesn't just slow you down — it costs real money. Here are the five most expensive mistakes Toronto homeowners make, with real cost impact for each.
Mistake #1: Skipping the Permit Entirely
What it costs: $322 to $29,457+ in surcharges alone
"My contractor said I don't need one." Famous last words.
When the City discovers unpermitted work — and they often do, through neighbour complaints, real estate transactions, or insurance investigations — you pay the 50% surcharge on top of regular permit fees. The minimum surcharge is $214.79. The maximum is $29,456.99.
But the surcharge is just the beginning. Under the Ontario Building Code Act, individuals face fines up to $50,000 for a first offence and $100,000 for subsequent offences.
Then there's the real damage:
- Stop-work order — your project halts while you retroactively apply
- Tear-out — the City may require you to open walls so inspectors can see what's behind them
- Insurance denial — your insurer can refuse claims related to unpermitted work
- Resale nightmare — buyer's lawyers pull permit histories, and missing permits kill deals or slash your sale price by $10,000–$50,000
The permit for a deck is $214.79. The cost of skipping it can be 100x that.
Source: Working Without a Permit (toronto.ca)
Read our full breakdown of no-permit penalties →
Mistake #2: Submitting Without a ZAP Certificate
What it costs: 4–12 weeks of delay
The Zoning Applicable Law (ZAP) Certificate confirms your project complies with zoning. It costs $214.79–$644.38 depending on your project.
Here's what most homeowners don't realize: without a ZAP, your application is considered incomplete by Toronto Building. And incomplete applications have no guaranteed review timeline.
The City's official review targets — 3 days for Express, 10 days for House Stream — only apply to complete applications. Submit without a ZAP, and your application goes into a different queue. You'll wait. And wait.
Worse: if your project doesn't actually comply with zoning (setbacks, lot coverage, height), you'll need a minor variance from the Committee of Adjustment. That process takes months and costs additional fees. Discovering this after submission — when your contractor is booked and your budget is set — is devastating.
The fix: Check zoning compliance before you submit. Get your ZAP certificate early. If there's a zoning issue, address it before you apply for the building permit.
Source: Building Permit Review Streams (toronto.ca)
Mistake #3: Using Outdated Forms or Incomplete Drawings
What it costs: 2–6 weeks of delay per resubmission
As of February 16, 2026, Toronto requires the updated Application to Construct or Demolish form. Submit the old version? Rejected at intake. You resubmit, you lose your place in the queue, and the review clock resets.
Incomplete drawings are even more common. The examiner needs to see:
- Clear dimensions on all plans
- Structural details (post sizes, beam spans, footing depths)
- OBC-compliant details (railing heights, fire separation, egress)
If your drawings are missing critical information, the examiner issues a deficiency notice. Minor deficiencies mean back-and-forth communication. Major deficiencies mean your application is cancelled — and you start over from scratch.
Each resubmission resets the review timeline. Three business days for Express? That was for the first complete submission. Resubmissions go back to the end of the line.
The fix: Use current forms (download from Toronto Building Forms Index). Invest in professional drawings if you're not confident in your own. A $500 drafting fee is nothing compared to weeks of delays.
Mistake #4: Not Knowing What's Express-Eligible
What it costs: 7–27 extra business days of wait time
Toronto's Express Services reviews qualifying applications in 3 business days. House Stream takes 10. Complex Stream takes 30.
The difference between knowing your deck is Express-eligible and accidentally submitting through the wrong channel can be weeks of unnecessary waiting.
Projects that qualify for Express include:
- Decks, porches, carports
- Detached garages and sheds
- Interior alterations
- Basement walkouts and underpinning
- Stand-alone plumbing
- Solar panels
Projects that don't:
- Additions (House Stream — 10 days)
- Garden and laneway suites (House Stream — 10 days)
- Heritage properties (additional review)
- Attached garages (House Stream)
Submitting an Express-eligible project through the standard process means you're waiting in a longer queue for no reason. And submitting a non-Express project expecting a 3-day turnaround means you'll be frustrated when it takes three times longer.
The fix: Know your stream before you submit. Check your project type here.
Mistake #5: Leaving Permits Open
What it costs: $5,000–$50,000+ off your sale price
You got the permit, you built the thing, your contractor moved on. Life happened. You never booked the final inspection. The permit sits open on your property's record — for years.
Then you sell your house.
The buyer's lawyer orders a Property Information Report from the City. Every open permit shows up. The buyer's lawyer advises caution. The buyer asks: "What was never inspected? Is the work up to code? What's hiding behind those walls?"
Now you're in one of three scenarios:
- You close the permit retroactively — booking inspections, possibly opening up finished work for the inspector to see, paying for repairs if anything isn't to code.
- The buyer demands a price reduction — typically $5,000–$50,000 to cover their risk and remediation costs.
- The buyer walks away — and the next buyer has the same questions.
Open permits are surprisingly common in Toronto, especially on older renovations. If you have any, deal with them now — on your schedule, not during a time-pressured real estate transaction.
The fix: After every project, book the final inspection and close the permit. Check your property's permit history through the City's online system. If you have old open permits, start the closure process today.
The Common Thread
All five mistakes share the same root cause: treating the permit as an afterthought instead of a project requirement.
The homeowners who save time and money on permits are the ones who:
- Check requirements before they start designing
- Submit complete applications with current forms
- Know which review stream applies to their project
- Close permits after construction is done
- Ask for help when the process is outside their expertise
Don't Make These Mistakes
Check if your project needs a permit — it takes 60 seconds and could save you thousands. If you want it done right the first time, PermitEasy handles the entire process: forms, drawings, ZAP certificates, submission, examiner communication, and permit closure.
The permit isn't the exciting part of your project. But getting it wrong is the most expensive part.
Share this with a friend who's planning a renovation — it might save them a very expensive lesson.