Building permits for cities across Ontario:

Toronto:

https://www.toronto.ca/services-payments/building-construction/apply-for-a-building-permit/

Mississauga:

https://web.mississauga.ca/services-and-programs/planning-and-building/building-permits/before-you-apply/

Oakville:

https://www.oakville.ca/residents/permits.html

Brampton:

http://www.brampton.ca/en/residents/Building-Permits/homeowners/Pages/welcome.aspx

Richment Hill:

https://www.richmondhill.ca/en/register-apply-or-pay/Building-Permits.aspx

Markham:

https://www.markham.ca/wps/portal/home/business/building-permits/guide-to-building-permits/02-guide-to-buidling-permits

Milton:

https://www.milton.ca/en/build/buildingpermits.asp

Hamilton:

https://www.hamilton.ca/home-property-and-development/building-renovating