They say a man's house is his castle, but a landlord has to share his castle with his tenants. Even though the landlord owns the property, the tenants possess it. Both sides have rights that the other is obligated to respect. State law may allow a tenant to change the lock, but it has to be done with consideration for the landlord's rights.
Habitability
A tenant has the right to a habitable apartment. That includes utilities, no leaks, safe electrical wiring and a secure entrance with a secure front door. Some states specify that the landlord has to replace the locks when a new tenant moves in to ensure the former tenant doesn't have access. If the landlord refuses to make needed repairs, many state let the tenant do it and withhold the cost from the rent. Texas law specifically says a tenant can do this if the landlord doesn't re-key the locks within seven days of a written request.
State Law
Even if the front door lock is sound, a tenant may want a new one or an added lock for her own piece of mind. She should check state law before taking action because the rules vary. A tenant in a New York apartment buildings has the right to add a lock of her own to the front door. Florida doesn't guarantee her the right, but it doesn't forbid it either: Unless the lease says otherwise, she's free to do it. Both states, however, require the tenant give the landlord a duplicate key.
The Right of Entry
Most state laws say that except in emergencies, landlords can only enter a rental without permission to make repairs, assess the need for repairs or to show the property. Each state sets how much advance notice the landlord has to give. If he or his employees break the law and enter whenever they want, changing the locks and not sharing the key is not a legal solution. The tenant should sue or complain to a local housing board instead.
Considerations
Whatever problem a tenant has with her landlord, she should put it in writing. Whether the problem is the landlord's employee entering illegally or a broken lock, letting the owner know may solve things. Even if it doesn't, it gets the issues down in writing. If the case winds up in small claims court, having a written trail helps prove that the landlord didn't act on tenant requests.
