You know a universe is big when your expansions requires more hard drive space than most full games.
One of the interesting pieces of information to emerge today after the publishing of The Full List of PS4 Game Install Sizes (some 460 games) was an install size for upcoming expansion Destiny: The Taken King. Despite being able to leverage all the exciting code and assets already installed on your system, it will still be a 17.4GB install, a hefty sum.
A full list of Xbox One game install sizes exists too, but does not feature Destiny: The Taken King. Surely it will be very similar, however.