The Boca codes require any [glow]pool[/glow] to have a 4 foot high barrier between the water and a person. A spa is not a pool but the codes are up to the interpertation of the local official.
When I was planning my tub and deck project, a township engineer wanted me to have the tub setback to the pool setback from my house. LUCKILY the head person was there and instructed her that this wasn't a pool and doesn't have the same requirements.
My suggestion is to find out what year codes your township uses, go to the library and copy the codes and know them well. Politely ask to speak to the head Inspector or Engineer of your township and talk it over with him/her. There might be a misinterpertation of the codes and this can set it right, I have found my township to be pretty good at answering questions.
Good Luck!