15 questions to ask a contractor before you hire them

The credentials block (questions 1-5)

1. Can I see your WSIB clearance certificate? Good answer: it's in your inbox before the meeting ends. Ending answer: any version of "we don't really need that."
2. Can I see your certificate of insurance? $2 million commercial general liability is the residential standard; you want the policy current and the contractor named.
3. Who does your electrical, plumbing and gas work? Ontario requires an ESA-licensed electrical contractor, certified plumbers, and TSSA-registered gas techs. "My guy handles it" is not a licence.
4. How long have you operated under this business name? Companies that dissolve and reopen under new names are a documented Ontario pattern; continuity is the tell.
5. Where's your business address? A real local presence means the warranty has somewhere to live.

The money block (questions 6-10)

6. What deposit do you ask for, and what does it buy? Around 10%, itemized against materials, per the province's own guidance. The deep dive is in our deposit explainer.
7. How are payments staged? Milestones you can inspect, not calendar dates.
8. How do you handle the 10% Construction Act holdback? A pro explains it before you ask; it protects you from subcontractor liens.
9. How do you price changes mid-job? Written change orders, signed before work proceeds.
10. Is your quote itemized with allowances named? A single lump number hides everything.

"Nobody's offended by these questions except the people you're trying to filter out. When I sit across from a homeowner running this list, I relax, because an informed client is the easiest client I'll ever have."

Mitch Fraser, owner, Ontario Contracting Co.

The execution block (questions 11-15)

11. Who pulls the permit? They do, in their name, verifiable in the municipal system. The reasons are in the permit rules for your municipality.
12. Who is my single point of contact? Poor communication is the #1 reported contractor complaint; a named person with a response window fixes most of it.
13. What's the start date, and what's your current job load? Overbooking is why jobs stall.
14. What does your warranty cover, in writing? Renovations have no Tarion backstop, so the contractor's written warranty is the whole warranty.
15. Can I speak to two past clients and see one current job site? A current site shows you the daily reality: containment, tidiness, crew conduct.

Print this list, run all three contractors through it (the shortlisting method is in the step-by-step hiring guide), and the decision usually makes itself.