436 Investors

What is the MAXIMUM number of fully-satisfied Old World houses you can have with just ONE of each public building (power plant, marketplace, pub, etc.)? The answer is 437. One those houses won't upgrade to investors ... but that's OK, because you'll need at least 2 engineer houses to run the power plant.

Vanilla game, no DLC or mods.

Very large stamp. Hard to squeeze onto most islands. But oh so efficient.