Buildings that are already in the game, but you didn't notice.

[Bibor]

FLIPPING FORT
A fort building that provides no extra fort level.
Can only be built in capital province.
Cannot be maintained.
It can be only built if religious or revolutionary rebels are in proximity to your capital.

HUNTING LODGE
A special, invisible building that doesn't take up a building slot.
Triggers its effect only if you have a young heir with a total of 15 or more monarch points.

GRAIN MONOPOLY ORGANIZATION headquarters (GMO)
Self-built in capital if prerequisites are met.
Does not take up a building slot.
Prerequisites: any of the following: "Has Quest for the New World" idea; has a colony in Africa region.
Effect: Doubles the chance for Grain in new colonies (displacing Gold, Ivory, Dyes and Gems).

CONFIRMATION BIAS FORT
effects: provides current max, level fort effects but enemies still siege it down 50% faster
cost: same as current maximum level forts

COURTHOUSE
effects: -0.1 autonomy, -25 % state maintenance.
cost: 100 ducats

TOWN HALL
effects: -0.2 autonomy, -50% state maintenance.
cost: 200 ducats

 

[MagnusDux]

GRAIN MONOPOLY ORGANIZATION

lol

 

[petertju]

GRAIN MONOPOLY ORGANIZATION

I think you mean Fish xD

 

[Mansa Sekou]

CONFIRMATION BIAS FORT

Its not comfomation bias if it happens every single time. There is NO way that I, me, the greatest, could ever get unlucky.