Let me throw the following into the mix.
In an quick and dirty Lexis search, I could not find a US Supreme Court case of 1988 or 1989 that dealt with age discrimination in housing or 55 plus housing. The "landmark" case of that year dealt with eviction from public housing.
And, by the way, the 1988 law is entitled, "The Fair Housing Act Amendments of 1988" (FHAA) which builds upon the "Fair Housing Act" of 1968. (FHA) The statutes were further amended in 1994 and 1998.
I did find and quickly review an article from the
St. John's Law Review (1999),
"The Fair Housing Act amendments and age restrictive covenants in condominiums and cooperatives." Here is a pertinent quotation:
There were several purposes recognized by Congress in allowing 20% of the units to be occupied solely by persons under the age of 55. One purpose was to protect those persons younger than 55 when a spouse or other member of the household over the age of 55 dies or leaves the unit. See Implementation of the Fair Housing Act of 1988, 54 Fed. Reg. 3232, 3255 (1989) (considering the legislative history of the provision and reviewing the opinions of commentators).
It also protects incoming households, including, for example, those under the age of 55 who inherit a condominium from a loved one. See id. However, practical concerns preclude an owner from setting aside exactly 20% of the units. See id. Were an owner to attempt this, a significant risk of losing the exemption would arise if the over-55 resident in one of the units died, leaving only person(s) under the age of 55. See id.
Keep in mind that is is commentary, not statute or case law, and I have no special expertise in this area. I am reporting what I have found.
What this suggests is that a person buying into an 55+ community only has a reasonable expectation that about 80 percent of the units will be occupied by at least one person over the age of 55. Such a purchaser should fully expect that a number of units may be owned and occupied by persons under 55 years of age, including by children.