On this site, every video carries a “Call a pro?” note and some jobs are marked Licensed pro only. This guide explains how we draw that line. The rules differ by state and province, so treat this as where to start, then confirm with your building department or licensing authority.
The short version
| Work | DIY? | Notes |
|---|---|---|
| Patching drywall, painting, caulking, trim | Yes | Test for lead and asbestos first in an older home. |
| Clearing clogs, replacing a flapper, faucet cartridge or supply line | Yes | Shut off the water first. |
| Replacing a faucet or toilet | Usually yes | Like-for-like fixture swaps rarely need a permit. |
| New plumbing lines, moving drains, a new water heater | Permit, often a plumber | Toronto requires a permit to install or modify plumbing and heating systems. |
| Replacing an outlet, switch or light fixture | Depends where you live | In Ontario, homeowners may, with an ESA notification. Elsewhere it may need a licensed electrician. |
| New circuits, panel work, the service from the street | Licensed electrician | Shut-offs alone don’t make panel work safe. |
| Anything on a gas line or gas appliance | Licensed gas fitter | Including gas water heaters, furnaces, ranges and dryers. |
| Removing or adding walls, cutting joists or beams | Permit and often an engineer | Ask whether the wall is load-bearing before touching it. |
| Disturbing suspected asbestos | Trained, accredited pro | Testing and removal both. |
Electrical
The danger isn’t only shock at the moment of the job. Loose connections and wrong wire sizes can start fires years later, inside a wall.
- Ontario allows homeowners to do electrical work in their own home, but even small jobs need a notification of work (a permit) filed with the Electrical Safety Authority before you start, a review when it’s done, and nothing covered up before ESA sees it. Friends, family and neighbours may not do the work for you.
- Other provinces and US states set their own rules. Some allow homeowner permits, others require a licensed electrician for almost everything. Ask before you buy parts.
- Always: turn off the breaker, then test with a non-contact voltage tester before touching anything. See How to shut off your water, power and gas.
- Call an electrician for a breaker that keeps tripping, warm or scorched outlets, flickering across several rooms, aluminum wiring, or anything inside the panel.
Gas
Treat gas work as licensed-only. In Ontario, the Technical Standards and Safety Authority tells the public to hire only registered contractors to install, service and inspect fuel-fired appliances, and it has fined a contractor for sending an uncertified worker to install a natural gas water heater. Many US states and cities also restrict gas piping to licensed fitters or plumbers.
If you smell gas, don’t look for the leak and don’t operate switches or anything that could spark. Leave the building, then call your gas utility or 911 from a safe place, and don’t go back in until the gas company says it’s safe.
Plumbing
Most fixture repairs are fine to do yourself. Call a licensed plumber for new supply or drain lines, sewer problems, a water heater (and always for a gas one), frozen or burst pipes inside walls, and any time you can’t stop a leak with the shut-off.
Structural
Removing or adding a wall, cutting into joists, rafters or beams, and enlarging window or door openings can change how the house carries its weight. Toronto requires a permit for adding or removing walls. A contractor or engineer can tell you whether a wall is load-bearing.
Asbestos and lead
- Asbestos: Health Canada says it was used mainly before 1990, in materials such as insulation, siding, floor and ceiling tiles, plaster, drywall, spackling and caulking, and vermiculite attic insulation. The EPA says: if in doubt, treat the material as asbestos and leave it alone. Don’t sample it yourself. Removal must be done by a trained and accredited asbestos professional.
- Lead paint: the EPA says homes built before 1978 are more likely to have lead-based paint. Health Canada says homes built before 1991 may have it. In the US, contractors who disturb paint in pre-1978 homes must be lead-safe certified.
Roofing
Falls are the risk. Hire a roofer for anything beyond a small repair you can reach safely from a ladder. Re-roofing with the same material often doesn’t need a permit (Toronto exempts it when no structural work is needed), but the job still belongs to people with fall protection.
How to check a pro’s licence
- Ask for the licence or registration number and check it with the issuing body. In Ontario, TSSA offers a contractor lookup and a phone line to confirm a gas technician’s certificate.
- Ask who pulls the permit. A licensed contractor should.
- Get the scope, price and cleanup in writing.
Related
- Do you need a permit? Common home projects in the US and Canada
- Jobs and systems: Electrical, Plumbing, and the Licensed pro only list.
Sources
- Electrical Safety Authority (Ontario). Do-It-Yourself (DIY) Electrical Work Source
- Technical Standards and Safety Authority (Ontario). Individual fined $6,000+ for employing unlicensed worker to install natural gas water heater Source
- Kansas Corporation Commission. Natural gas safety Source
- US Environmental Protection Agency. Protect your family from exposures to asbestos Source
- Health Canada. Asbestos and your health Source
- US Environmental Protection Agency. Protect your family from sources of lead Source
- City of Toronto, Toronto Building. When do I need a building permit Source