@Dentedhalo11 yes you're correct, if you have overlapping specializations of the same type then the population bonus is cumulative........... up to a maximum of 100% boost from any one type of specialization
so for example if you have one residence that is covered by one heliport you recieve 50% boost, if it is covered by a heliport and a balloon park you get a 80% boost (50+30), but if it is covered by two heliports and a balloon park (50+50+30) you only recieve a 100% boost
so in answer to your question ideally you want narrow beach buildings but with a wide boost area, sailormans pier can be a good one but it only reaches in land by 20 tiles
in any case the maximum population boost a residence can get is limited to 400% with a maximum of 100% from any one type
22000!!! wow, the biggest ive got on my city is around 14000 and thats an epic building!
