Yes, adding a sunroom can increase your home's value, with a return on investment (ROI) ranging from 20% for a screen room to 50% for a three- or four-season room. The amount of value added depends on the design. Fully insulated, temperature-controlled four-season sunrooms add the most value as they can be included in the home's total living space. In contrast, simpler structures like Arizona rooms or solariums typically have a lower return as they don't count as legal living space. A high-quality sunroom can also be an attractive feature for potential buyers, especially those who enjoy gardening. The value may also be higher in warmer climates where this feature is more sought after. When deciding, consider both the potential resale value and the personal value you will get from using the room.

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.

An enclosed porch can be considered a living space if it meets certain criteria. For instance, it must be completely enclosed with solid walls and a roof. It should also have a heating and cooling source similar to the rest of the home. Finally, the porch should have direct access to and from the interior of your house.

Your maintenance needs revolve around the type of foundation you choose, as well as how you furnish or decorate it. Patios require little else other than the occasional hose-down, but decks and other wooden structures will require annual power washing and sealing. You may also need to restain the wood every two to three years.

Adding a solid roof rather than building a pergola or leaving the space open will make maintenance much easier. Without a roof, you will need to spend more time sweeping, washing, and covering your furniture to protect it from UV bleaching.