Old buildings have terrible water pipes. No matter where you live or how swanky your neighborhood may be, if it's old, you're doomed to icy/hot showers that fluctuate based on which toilet is being flushed and which sink is running. For many people, this is just a mere inconvenience, but for others, who have snarky family members visiting, these old pipes turn into a weaponized warfare device that can only be wielded by the resident.