The family usually enters the house through or near the garage, so why not include a "drop-zone" for weather gear and a recharging station for cell phones as part of a mud room. It could also include space for the washer and dryer.
More detailed floor plans include “dimension strings” to locate windows, doors, walls and other architectural elements. Dimension strings are drawn parallel to the element with 45º “hash marks” at each end of the dimension string indicating where the measurement starts and ends
The "split" here is real estate speak for a floor plan that sets the master suite apart from the other bedrooms, for greater privacy, either on the other side of the great room, or on a separate floor. Often such a design works for families with older children.