Every time I say “flying buttress” he laughs. For some people, Notre Dame is a religious experience. Our promenade around the exterior was more like a giggly experience. Each time someone said “buttress,” it was pronounced “BUTT-ress.” You can’t take us anywhere. Nevertheless, I still think flying buttresses are cool and good for more than just a laugh.
Gothic churches are tall, spacious and filled with light. Why? The magic of technology. Buttresses support the walls outward force. Pointed arches (instead of the round Romanesque arches) allowed the enormous weight of stone roofs transferring it out and not just to the walls. Essentially, the buttresses support the weight of the roof. This made building thinner walls with windows possible.
You can see the support inside with a network of columns that become pointed. They intersect at the top of the roof.
Nowhere can you see this more than in Paris’ Sainte-Chapelle. Almost all the walls are windows and it is filled with light.