Getting into something good...
In order to get into the room you are going to need a door. There a different types of door, but since this is an interior room in a house, we are going to use an interior door. You will need to choose a style of interior door that you think would work well as an entryway into the room you are designing.
1. How much does the door you chose cost?
2. Calculate the area and perimeter of the door you chose.