A screened-in porch can add value to your home, with a potential return on investment (ROI) of 70% to 84%. The actual value added depends heavily on several factors. Climate is a major consideration; homes in warm, humid, or buggy areas (like the Southern regions) see the highest ROI. In colder climates, the value is diminished as the unconditioned space is unusable for much of the year. Other factors that influence the return include the quality of materials and construction, the size of the porch, and the local real estate market. While a screened-in porch can enhance curb appeal and attract potential buyers, it is not included in the home's total square footage for appraisal purposes.

While there is no one size that’s considered best, the sunroom size that’s best for you will come down to the size of your home and how you want to use your sunroom. Smaller sunrooms under 120 square feet provide a nice semi-outdoor sitting area, medium-sized sunrooms between 120 and 200 square feet can house an outdoor dining area and a small area for additional seating, and large sunrooms over 200 square feet can serve multiple purposes and even include an outdoor kitchen.

If you want to hire a professional to build a screened-in porch, a local sunroom or porch contractor is your best bet. If you can't find a local sunroom builder, another option is to consider hiring a general contractor to perform the work. 

If you're handy, you may consider building the porch yourself. Before you do so, make sure you understand the local permit requirements and building codes so that you don't have any problems with the safety or structure of the porch.

Prefab kits like a small sunroom for around $20,000 or even a basic gazebo roof for as little as $60 can save you big over professional installation. However, you lose the option for customization, and these structures tend not to last nearly as long. As for bigger projects like a deck or patio, you shouldn’t go with the DIY route unless you’re fully prepped with the tools and know-how to get it done right. Mistakes can be frustrating and costly, so choose a pro if you’re looking to eliminate your risk of error.