My tenant’s behaviour is causing my other tenants to feel uncomfortable, and he’s interfering with my right to conduct maintenance in the unit. At what point can I serve an N7 notice?
I do not think that the Landlord and Tenant Board will order termination based on an N7 in the case you are describing. An application based on a correctable N5 has a much better chance of succeeding, especially if another tenant is being affected by the behavior. Either way, you will require one or more witnesses to attend if you want to present your case well.
If the matter proceeds to the Board, it may be in your best interests to hire a paralegal or lawyer to represent you at the hearing.