Value/Return Rooftop Deck/Rooftop Terrace

[Kevin Fox]

I am considering building a rooftop deck/rooftop terrace on the rear side of an upper level addition.  Does anyone have any actual data on the return on this component (previous appraisals, paired sales analysis, comparison on new construction with/without rooftop decks)?  Any reference point of return?  

I see many town home new builds have this feature but likely because it allows higher density/lower cost of land since many lack yard area but the rooftop allows an outdoor feature.  The subject property is on a beautiful half acre and already has a patio.  I am building a vertical addition above the existing main level which would have vaulted ceilings OR alternatively the front half would be vaulted and rear where the bath/closet is situated would have flat ceilings with rooftop deck above.    

The home will already have a view of the water from the front of home and would be a superior view to the roof deck since it is on the rear of the home.  I am leaving out cost to build and sale price because I am strictly looking for any actual data or reference on the component itself which should give me a base line and hold true in most markets.  I don't want to dilute the return.  VERY MUCH APPRECIATED!