When major living areas have more than one door, circulation is more flexible and gracious.
A good floor plan makes the traffic flow between the major living areas easy and graceful, without creating bottlenecks or dead-end spaces that might trap guests at a party, or make it difficult to get from one part of the house to another. Here are examples of floor plans with flexible circulation.Plan 132-200.
Here the sliding door in the master suite's walk-in closet allows an easy connection to the laundry and the garage.
To get from the master suite to the laundry and the garage without such a door you would need to walk around the kitchen and through the great room.Plan 137-241.
In this layout the traffic flow is circular, from the front door through the living room to the dining room to the breakfast area and family room and then back to the foyer. The kitchen connects to the garage through the utility/laundry.Plan 520-3.
Except for the study near the front door, all the major rooms on the ground floor of this house have at least two interior entrances.
See the connections from the long hall and from each room to the other -- in addition to the doors to the courtyard, so there is always a way out.