I first noticed the phenomenon of red doors watching Mad Men. The front door of the Draper/Francis residence at 42 Bullet Park Road in Ossining, NY, is so red it glows.
I haven’t found any consensus about the meaning of the red front door. It seems to depend on the situation and the culture. It means something different in America than it does in China and it means something different on a church than it does on a house.
In Pittsburgh, red doors appear most commonly on churches (of all denominations), but also show up pretty often on bars and stores and schools and houses all over our charming little city. That makes them a perfect candidate for the Gallery of Local Nouns.
The photograph above is of the Fourth Presbyterian Church on Friendship Avenue.