I passed 21,000 words in the first book of my new science fiction series yesterday, officially making it a "novella" (novellas are traditionally 20-40,000 words long). I am just about to write the "climactic" final scenes, so the final length should be just under 23,000 words. As I go through my first real edit next, I might add a few bits of dialogue here and there, or even a new scene if it appears the story needs it, but in the end, the story will top out at no more that 25,000 words, so a novella it is.
this story to my first full-length (95,000-word) novel, Cyberdrome, I
have to say I really prefer shorter works. It's not that I'm lazy; it's
just that I really prefer to read medium-length stories, especially if
there are more stories to come in that universe (I have outlined 4
stories in this series.) Novellas tend to be more concise and to the
point (i.e. there is no room for rambling dialogue or "filler" chapters
in a 20,000-word story.) Novellas are also closer to the structure of
screenplays, which to me is a good thing.
More on the uniqueness of novellas in the link below: