A useful quote I found:
"For example you might find that a lot zoned for single family residences require homes with a minimum square footage larger than you intend to build. But you may also notice that there are no minimum size requirements for properties zoned for multi-family residences. This is because these zones allow for duplexes and apartments and different rules apply to these kinds of projects. Theoretically you could use this to your advantage by getting a permit to build one tiny house and still leave the option open for building another later."