Roof Replacement Permit: When Ontario Requires One
What Toronto, Mississauga and Brampton say about re-roofing, the roof work that does need a permit, and the other approvals on a commercial job.
Call 1-833-775-7663 Oakville head office · Flat roof repairs, replacements and inspections for commercial, industrial and institutional buildings across Ontario
Karol Rajkowski
Vice President, OYH Roofing
Published October 8, 2026 · 8 min read
Short answer
In Ontario, a roof replacement permit is usually not needed when the new roofing simply replaces the old and no structural work is involved; Toronto, Mississauga and Brampton all say so. A permit is needed when the job changes the structure, the roof height or slope, or adds rooftop HVAC, solar panels or a green roof.
Do you need a roof replacement permit for a commercial building in Ontario?
Usually not, when the new roof replaces the old roofing and nothing structural changes. Ontario's Building Code Act requires a permit to construct a building, and "construct" includes the material alteration or repair of a building, so the question is whether your job counts as one.
Each municipality's chief building official decides whether a job needs a roof replacement permit. Toronto, Mississauga and Brampton publish lists of common projects, and all three put a straight replacement of roofing on the no-permit side while drawing the line at structural changes. The lists are examples, not the law itself, and none of them removes the need to meet the zoning by-law.
What do Toronto, Mississauga and Brampton say about re-roofing?
None of the three asks for a roof replacement permit when the job is like-for-like with no structural work. They differ on wording: Toronto speaks of "roofing material", while Mississauga and Brampton word their exemption around shingles, so owners of flat membrane roofs in those two cities should confirm with the building department.
| Municipality | No permit needed | Permit needed |
|---|---|---|
| Toronto | "Replacing existing roofing material provided no structural work is required"; adding or replacing insulation | Structural or material alterations; green roofs and rooftop storm water retention systems; solar collector systems; installing or modifying heating systems |
| Mississauga | "Re-shingling a roof" | "Roof extensions or alterations to increase the height or change the slope"; rooftop HVAC replacements; skylights; solar panels; fire damage repair |
| Brampton | Replacing asphalt shingles "without any alterations to the structure of the roof or building" | Not exempt: work that alters the roof or building structure |
| Oakville and other municipalities | Oakville's building permit page does not list roofing. Ask the building department before work starts. | |
What roof work needs a building permit?
Work that changes the structure or adds to it: replacing or reinforcing the deck and framing, raising the roof or changing its slope, and adding or replacing rooftop systems such as HVAC units, solar panels, skylights or a green roof.
| Roof job | Building permit? | Where it is listed |
|---|---|---|
| Replace roofing, no structural work | Usually no | Toronto, Mississauga, Brampton |
| Add or replace insulation | No in Toronto | Toronto |
| Replace or reinforce the deck, joists or other structure | Yes | Toronto (structural alterations), Brampton |
| Raise the roof or change its slope | Yes | Mississauga |
| Replace or add rooftop HVAC | Yes | Mississauga (rooftop HVAC replacements); Toronto (heating systems) |
| Add solar panels | Yes | Toronto, Mississauga |
| Add a green roof or rooftop storm water retention | Yes | Toronto |
| Add skylights | Yes in Mississauga; Toronto exempts some on buildings of 3 storeys or less | Mississauga, Toronto |
| Repair fire damage | Yes in Mississauga | Mississauga |
The deck is where plans change. The Canadian Roofing Contractors Association points out that only a full tear-off exposes the deck, nailers and blocking for inspection, so rusted steel or rotted wood often shows up after the old roof is off. If the deck needs structural repair, call the building department before it is rebuilt, and ask your roofer to price that scenario in the quote.
A tear-off is also the time to plan rooftop work. Flashing new curbs, solar racking or a green roof into a new membrane is simpler than cutting into it later, and each of those items needs its own permit. Our roof flashing repair guide explains how curbs and penetrations are flashed.
What other approvals does a commercial roof replacement need?
Even without a roof replacement permit, a commercial re-roof can require a Notice of Project to the Ministry of Labour, an asbestos report from the owner, WSIB clearances for the contractors, heritage consent on a designated property, and compliance with zoning.
| Approval | When it applies | Who handles it |
|---|---|---|
| 1. Notice of Project | The total cost of labour and materials is expected to exceed $50,000 | The constructor, before work begins |
| 2. Asbestos examination and report | Before tendering or arranging the alteration or repair | The owner, who gives the report to prospective constructors |
| 3. WSIB clearance | Before the work begins and for its duration; a clearance is valid for up to 90 days | The owner or general contractor, from each contractor |
| 4. Heritage consent | The work is likely to affect the heritage attributes of a designated property | The owner, who applies to municipal council |
| 5. Zoning | Always, even when no permit is needed | The owner |
Notice of Project
Ontario's construction regulation, O. Reg. 213/91, requires the constructor to file a notice with the Ministry of Labour before work begins on a project expected to cost more than $50,000 in labour and materials. For a job of 14 days or less, the constructor can instead give the details to the nearest Ministry office by fax or phone.
Asbestos and WSIB
Under O. Reg. 278/05, the owner must have material that is likely to be disturbed examined for asbestos before requesting tenders or arranging the work, and give the report to prospective constructors. Ontario's list of suspect materials includes roofing felt and base flashing; our tar and gravel roof guide explains how this applies to older built-up roofs. On WSIB, the board says a valid clearance gives the principal assurance that it will not be held liable for premiums and other amounts the contractor owes for the clearance's validity period. Clearances can be checked online, and they last up to 90 days, so renew them on a long job.
Planning a roof replacement?
We will assess the roof, flag anything that may need a roof replacement permit or an asbestos survey, and give you a written quote.
Call 1-833-775-7663Request an assessmentWhat happens if you renovate without a permit in Ontario?
The chief building official can order the work stopped, and a conviction under the Building Code Act carries a fine of up to $50,000 for a first offence by an individual and up to $500,000 for a corporation.
Repeat offences raise the maximums to $100,000 and $1,500,000. Failing to comply with a stop work order adds up to $10,000 for every day the offence continues. The City of Toronto warns that missing permits can mean costly construction delays, legal action or the removal of work already completed. The building owner is ultimately responsible, so ask your roofer to confirm in writing whether the scope needs a roof replacement permit or includes anything else on the permit lists.
Do roofers need to be licensed in Ontario?
No provincial licence is required. Roofer is a non-compulsory trade with Skilled Trades Ontario, so certification is voluntary, although roofing is a Red Seal trade.
That puts the checking on the owner. Before signing, ask for:
- A WSIB clearance for the roofer and any subcontractors, checked online.
- Proof of liability insurance naming the work on your building.
- The manufacturer's warranty terms for the system being installed; our commercial roof warranty guide lists what to ask.
- A written scope that says who handles the Notice of Project and any permit, and how deck repairs will be priced.
For planning the replacement itself, see our warehouse roof replacement guide, our apartment building roof replacement guide for occupied buildings, and our commercial flat roof lifespan guide for the repair or replace decision. You can also see our roofing services and completed projects, including Devi Mandir in Pickering, where two old roof layers and a coating were torn off before a new 60 mil TPO roof went on.
Frequently asked questions
Do I need a permit to reshingle my roof in Ontario?
Usually not, if no structural work is involved. Mississauga lists re-shingling a roof as work that needs no permit, Brampton exempts replacing asphalt shingles without changes to the roof structure, and Toronto exempts replacing roofing material when no structural work is required. The rules are municipal, so check with your city first.
What happens if you renovate without a permit in Ontario?
The chief building official can issue orders, including a stop work order. Under the Building Code Act, a conviction can bring fines of up to $50,000 for an individual's first offence and up to $500,000 for a corporation, plus up to $10,000 a day for ignoring a stop work order. Work may also have to be removed.
Do roofers need to be licensed in Ontario?
No. Roofer is a non-compulsory trade with Skilled Trades Ontario, so certification is voluntary, although it is a Red Seal trade. Owners should instead ask for a WSIB clearance, proof of liability insurance, the manufacturer's warranty terms and a written scope before hiring a commercial roofer.
What renovations require a permit in Ontario?
The Building Code Act requires a permit to construct or demolish a building, and construction includes erection, installation, extension, material alteration or repair. City lists include additions, structural alterations, new or enlarged windows and doors, heating and plumbing work, solar panels, green roofs and changes of use.
Do I need a permit to add solar panels or HVAC units to a roof?
Usually yes. Toronto and Mississauga both list solar panels as permit work, Mississauga lists rooftop HVAC replacements, and Toronto lists installing or modifying heating systems. Plan these items with the roof replacement, so curbs and racking are flashed into the new membrane instead of cut in later.
Who files the Notice of Project for a roof replacement?
The constructor. Under O. Reg. 213/91, the constructor files the notice with the Ministry of Labour before work begins when labour and materials are expected to cost more than $50,000. When an owner hires one roofing contractor to run the whole job, that contractor is normally the constructor; the contract should say so.
Karol Rajkowski
Vice President · OYH Roofing
Karol Rajkowski is Vice President of OYH Roofing, an Oakville-based ICI flat-roofing contractor whose projects include the City of Mississauga building at 3185 Mavis Rd and the Marriott Hotel in Vaughan. Learn more about the OYH team.
Sources
- Building Code Act, 1992, sections 1 (definition of "construct"), 8, 14 and 36, Ontario e-Laws.
- When Do I Need a Building Permit?, City of Toronto, modified July 21, 2026.
- When a building permit is required, City of Mississauga.
- When a Permit is Not Required, City of Brampton Building Division.
- Building Permits, Town of Oakville.
- O. Reg. 213/91: Construction Projects, section 6, Ontario e-Laws.
- O. Reg. 278/05: Designated Substance, Asbestos on Construction Projects and in Buildings and Repair Operations, section 10, Ontario e-Laws.
- Clearances, WSIB, updated May 5, 2026, and Questions and answers: Clearances, WSIB, updated July 20, 2026.
- Ontario Heritage Act, section 33, Ontario e-Laws.
- Roofer, trade information, Skilled Trades Ontario.
- Roof Re-Covering: An Alternative?, Technical Bulletin No. 48, Canadian Roofing Contractors Association, June 1999.
- OYH Roofing project records: residential new build, Sault Ste. Marie; Devi Mandir, Pickering (October 2026).
OYH Roofing, 2120 Speers Rd, Oakville, ON L6L 2X8 · 1-833-775-7663 · info@oyhroofing.ca