It's recommended (and in some jurisdictions, required) that a landlord conduct a property inspection at least twice with each new tenant: once before the tenant moves in and again when the tenant moves out. This helps tenants and landlords understand who is responsible for any repairs that are needed.
For example, if an initial inspection showed the walls of the rental unit were in good condition when the tenant moved in, but a second inspection noted significant scratches, holes, or other damage when the tenant moved out, it's likely the tenant will be held responsible for the cost of these repairs.
Some jurisdictions set out guidelines for when an inspection can take place in a rental property. For instance, a law might require inspections to occur one week before the tenant moves in and one week after the tenant moves out, between the hours of 8 a.m. to 8 p.m., and never scheduled on a holiday. For inspection timelines and requirements in your province or territory, you can consult your local landlord and tenant board.
Further, a landlord may wish to do routine inspections throughout a tenancy for regular maintenance and to address any issues (like a leaky faucet) before they cause significant damage. Routine inspections are up to the landlord's discretion and can occur once, twice, or as many times throughout the tenancy as the landlord would like. However, it is important for landlords to give tenants adequate notice before performing the inspection and to respect tenants' right to live in the property free from unreasonable interference.