The Hoa can allow any height , it is a choice that you and the Hoa would make.
The Federal Antenna Law is written as , 12 feet above the highest part the roof is your wright , and above that it is what you and the Hoa work out.
http://www.fcc.gov/mb/facts/otard.html.
Even so there is no increase of signal strength going higher the then 30 feet so 20 or 30 feet it is.