It's exactly like the royal points for an expansion. You can have the royal points needed to expand, and that part gets checked off. Then, if you put away a building that has royal points, you now don't have the required royal points but it stays checked off. Then if you try to expand, the game won't let you, because you no longer have all the royal points needed to expand. When I first started playing, that tripped me up. So you can still make your brews. Just don't drop below 80 Fire Flowers.