This activity is designed to familiarize students with how a greenhouse retains heat by building simple models. As a result of this activity, students will come to understand that greenhouses are useful because they both allow sunlight to enter and prevent heat from escaping. The transparent covering of the greenhouse allows visible light to enter unhindered, where it warms the interior as it is absorbed by the material within. The student guide has an overall description of the activity, a list of materials, the procedure, and observations and questions. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.