It's an excellent concept to send out one of your survivors to the door unlocking the next area ASAP if you have a great coat geared up. The important things is that you will constantly (or often a minimum of) require to find some items or do some things prior to getting to the next area. These jobs will be carried out in the structures you'll check out anyhow. If you know from the starting what has actually to be done for you to unlock the next area, you get a benefit and will not have to review a building several times, losing important time and resources in the procedure.