This was from the Godzilla encoutner and is not a part of the actual movie.
However, I can answer your inquiry about size. The elevator stopped at floor 35, which, according to modern American Architecture, can measure 355 feet for a hotel style building (unlikely), or around 450 for an office building. That range is expected given how Gareth Edwards said his Godzilla would be "just about" the biggest Godzilla ever.
We have some geniuses on this site who think he's going to be 779'+, and they're absolutely incorrect beyond the shadow of a doubt.
This footage is not from the film, but it does represent the accurate kind of portrayal they'll be using for Godzilla in the movie. I believe this is his official size as well, which again makes sense given Edwards comments.
But again, this was not from the movie.