Sketch out a baseball diamond blueprint. Different leagues have different base and layout requirements. Little League fields have bases spaced 75 feet apart; adult league fields have 90-foot base layouts. Softball fields most often have 60-foot base layouts. Pitcher's mounds placement depends on the age of the players and the type of ball being played. Distance from the pitching rubber to the home plate ranges from 35 feet to 60 feet 6 inches.
Measure actual field space. The size of your dugout will depend partly on the space where you will be building it. Fields that are in open areas can have dugouts that are larger than fields in enclosed lots where spacing is minimal. Using a tape measure, jot down how much space you'll have on each of the two sides of the playing field.
Evaluate team space needs. A Little League dugout does not need to be as big as one intended for adult use. Figure on two feet of seat space per child and three feet per adults. Plan enough spacing in front of the bench to allow people to move freely. Plan an area outside the dugout where batters who are next at bat can stand or warm up.
List materials needed. The simplest needs of any baseball or softball team are places to sit, fencing to protect from stray balls and places to store equipment where it can be reached easily. You'll want enough wood or brick to build walls and metal or wood to build a roof to protect your players from the sun when not on the field. Include wood stain to protect the walls, bench and roof from the elements. If the sun isn't a major problem in your area, walls can be made out of simple fencing material.