Your house has several doors that require locks. Should all these locks use the same key? Some can, but some should not due to privacy reasons. If your concern is that several people will be renting rooms in your home and will need keys to get in, you have a couple of options for avoiding the problems associated with the renters possibly losing their keys.

External Versus Internal Door Locks

The answer really relies on the type of lock. External locks are probably best kept on the same key, and a locksmith can reset all of the locks for you. Internal door locks are different. These locks tend to be things that go on bedroom doors. Those locks should all use different keys so that the occupants can feel like that room is their private space that no one else has a key to.

Multiple Keys and Changing Every Lock

Houses tend to not have that many exterior doors. You'll have the front door and possibly a side door into the garage; if the back door is a sliding door, it likely won't have a key. However, French doors would, yet that's still not a lot of locks. Using the same key for all would be fine as long as you realize that you'll have to change all of the locks if you lose a key. The alternative is to have one key for the front door, another for the side door, and so on. But, you can see how inconvenient that could be as it would just lead to more keys on your keychain.

Limiting the Number of Keys 

For people who rent out rooms in their house, such as for vacation stays, or for students who stay only for a short while, the idea of handing out several keys seems risky. If one key is lost, and you're using the same key for all the locks on the exterior doors of your house, then you have to change all the locks (or rekey them). Using one key for the front door but another key for all the others is one solution, but if you're trying to use only one key for all the doors, that, of course, isn't going to work. Another solution is to use electronic or smart locks on all the doors, have all the keyholes keyed to the same key, and issue different PINs to people who are renting (and they would not get a key). Changing PIN numbers is fairly easy. A locksmith can install these locks for you.

You can certainly use the same lock on all the exterior doors of your house. You may want to use different keys for locks inside as individual locks give people a sense of privacy. A locksmith can install all of these if needed and set the external locks so that they all use the same key.

Contact a local residential locksmith service to learn more.