Godzilla has frequently been increased in size so that he can still look massive compared to the increasingly taller skyscrapers he demolishes. From Godzilla (1954) to Terror Of Mechagodzilla, he was 50 meters high. The Return Of Godzilla made him 80 meters high. And from Godzilla vs. King Ghidorah to Godzilla vs. Destoroyah, he was 100 meters high. Then Godzilla (2014) comes along with the makers of the film promising that this would be the biggest incarnation of Godzilla yet. As this Yahoo! Movies article puts it:
"Godzilla's always been rather large. But now he's, like, really rather large."