You'll need to clear 44GB on your PS4's HDD to install Uncharted: The Nathan Drake Collection when it releases on October 9th.
PSU reports that the package will take up 44.46GB of space on your system's hard drive, which is pretty decent considering there are three games on there.
The Nathan Drake Collection features remastered PS4 versions of the three PS3 Uncharted games, Drake's Fortune, Among Thieves, and Drake's Deception. These games all have improved graphics and sound, extra difficulty levels, photo modes, and other enhancements.
Buying the Collection will also guarantee access to Uncharted 4: A Thief's End multiplayer beta, which runs from December 4th to 13th.