Hi Jacky
Regarding the frosted glass, possibly not, although it can alter the amount of natural light that penetrates a room, which could have an impact.
However, enclosing the balcony can change the fire-rating of a building, affect the amount of the light/ventiliation entering the adjacent rooms of your apartment and of course, quite potentially include an additional ‘habitable’ space which deviates from the original plans in the DA. This may have had an effect on the issuing of the occupancy certificate.
I hope you had council approval to enclose the balcony, as EC approval only is probably not sufficient; the issuing of an occupancy certificate to the developer hinges on the building conforming to certain standards upon completion – the enclosure is unlikely to meet that requirement.