In the spring we had a client come to us with an existing deck which needed some refreshing. In this case the existing deck was fairly old and the existing wood was starting to go. The old deck had a very nice pergola on one side that gave the home owners a bit of shade in the afternoon but didn't fully protect them from the warm summer rays and of course did nothing to stop them from getting wet in the event of an afternoon shower.
The dream was to have a new deck built using about the same foot print of the existing deck but the main goal was to replace the pergola with a proper roof. This would allow for full protection from the elements and allow the living space to be used no matter what the forecast.
The above transformation is pretty spectacular. The deck was able to be updated with more current products such as the ornamental screens on the side, we added a step down to a protected BBQ area, and of course the fully finished roof sets a dominate presences and allows for countless hours of enjoyment. The deck was finished off with vertical board skirting, 2x4 fascia and also has wrapped steps for a very clean polished look.
Taking what you have and altering it to what you need can be done with some planning and expertise. Heritage Design would love to come and take a look at what you are dreaming up.