Film compared to original Cheever story

I just read the Cheever story, and was amazed at how much more developed the film is. The original story is truly a 'short' story you can read in 20 minutes. Most scenes pass in a few words or sentences. Ned spends very little time with any of these neighbors. Entire scenes were invented for the film. The babysitter character does not appear in the story at all. Much of this surprised me. I think both the film and the story are excellent, but this may be the rare case where the film improves on the story, by developing Ned's character a bit more and by fleshing out the other people in the story.
To anyone who admires this film, I highly recommend reading Cheever's story.