sometimes exceptions can be made especially if you are purchasing new construction and the build out time frame is 6 months or longer.
My advice is ask the community you are interested in. If you get an answer that does not please you but you are in 'love' with this community/lifestyle then go over to ask the developer, better yet, get a good Real Estate agent who can assist you with negotiating. This is what we do best! :/)
In most communities at least one person must be at least 55 to live in the community, but you don't have to be 55 to buy in the community.
There are many "Active Adult" communities where you do not have to be 55 to live there. These communities have an 80/20 rule, where if 80% of the population is over the age of 55 the other 20% can be under that age.
If I can be of further service please contact me directly.