People often come to our locksmith shop on Yonge Street and ask for ways to keep their landlord from entering their apartment while they’re out. This can be a difficult task, especially when the apartment building in question has a master key system. One of the solutions involves using a standard chain lock with a key cylinder that allows the tenant to lock the chain in place from outside before they lock the dead bolt. With this solution the landlord cannot enter the apartment without having the chain lock key or breaking the chain itself, even if he has a master key. Another solution, if allowed by the condominium corporation, is to take the lock off the master key system entirely, and supply a copy of the new key to the management in a signed envelope for use in verified emergencies only. With this solution the resident can request to see the signed envelope anytime and ensure no one has used the key to enter their unit.