Design a screened porch with Home Designer. This advanced program lets you plan your porch and even place the screens. This is all done through moving objects around with the mouse. The program will give you a warning if it does not think your design is structurally sound and even give you tips about how to remedy the problem. It costs $199.99 as of time of publication.
Plan the screened porch with HGTV Home & Landscape. This program offers a more basic interface than Home Designer and fewer tools, but, at $39.99, is also less expensive. You can build from the main visual interface or a floor plan.
Construct a model with Google Sketchup. This 3-D modeling program has one main advantage – it’s free – and one main disadvantage – it’s not specific to home design. This means it will help you create only rough sketches. But if you are in the early stages of planning and just want to play around without spending a lot of money on an official program, this is a good place to begin.