HST Rebates
https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/rc4028/gst-hst-new-housing-rebate.html

Non-resident sellers
https://www.canada.ca/en/revenue-agency/services/tax/international-non-residents/information-been-moved/disposing-acquiring-certain-canadian-property.html

First time buyers Land Transfer Tax
https://www.ontario.ca/document/land-transfer-tax/land-transfer-tax-refunds-first-time-homebuyers

Foreign buyers
https://www.ontario.ca/document/land-transfer-tax/non-resident-speculation-tax