Show the blueprint examples. Explain the process of creating a blueprint as well as its importance in construction.
Show kids how to draw a basic blueprint showing outer walls, doorways, interior walls and fixtures such as sinks and outlets. Depending on the age group, help the kids create a blueprint for a one-room playhouse, a treehouse or a single-story house.
Demonstrate how to use a ruler and graph paper to create a scale rendering of a floor plan. For example, show the kids that when using a scale of 1 inch to 1 foot, a 6-foot by 8-foot treehouse takes up six squares vertically by eight squares horizontally on the graph paper.
Show the treehouse's front door at the lower edge of the drawing on the long side of the floor plan. Draw a 2-foot wide door in the center of the front wall with a 1 1/2-foot window on each side of the door so the kids see how to divide a square into a 1/2 foot.
Show the kids how to use the compass to make circles on a blue print to indicate a pillar or another round object in the floor plan.
Demonstrate how to draw basic blueprint symbols, such as a circle marked "WH" for a water heater, a circle with two parallel lines for an electrical outlet and a circle with four rays for a light.
Help the kids to measure and draw interior walls, if needed for their designs, and to measure and draw door and window locations.