“Patio Enclosure” is a relatively broad category that can encompass projects as small as the $500 range, or as massive as $36,000. The average project (depending on what field you wish to include) will cost near $15,000. The final cost will be highly dependent on the size of the area being enclosed and how it is confined. Windows, materials, etc. Either way, the end result will be a room that makes the best of both nature and comfort.