The cost of building a porch enclosure can vary based on the type of materials used, the size of the project, and the complexity of the design. The cost of labour will also factor into the overall cost, as will the time needed to complete the project. For example, a screened-in porch enclosure with a simple design may cost less than one with a more intricate design. In addition, the cost of materials such as wood, aluminum, glass, and screening will also affect the total cost of the project. It is important to get an accurate estimate of the cost of building a porch enclosure before beginning the project.