How do I enter and exit buildings?

(FOLLOWING UP: I FOUND AN ANSWER TO THIS QUESTION. if you have any questions on the topic I should be able to help)

Ideally I would like to use the multi-scene way of doing it. By loading a new scene once I open the door and reloading the previous scene when I exit the door. However whenever I leave said door the script I used reloads the level from the beginning. Any help??? I want at Skyrim/GTA style way of entering and exiting places in the means that when you exit the building you are at the door.

As @rutter indicates, you need to read on DontDestroyOnLoad, Application.Loadlevel and static