How does a building answer climate, power and money at once?
French architecture is unusually legible because it has spent a thousand years solving the same three problems at increasing scale: heat, defence and the price of land. The Gothic cathedral solved height with a skeleton of ribs and flying buttresses; the château solved defence and display at once; Haussmann's Paris solved the price of land by legislating a uniform height and then building to it. This pillar reads buildings as machines — what they hold up, what they keep out, what they cost per square metre — rather than as monuments.
In this pillar
The Gothic vault as a skeleton
The rib and the flying buttress are a structural frame, not decoration; they let stone carry height it could not carry as a wall.
The château as defence and display
The Loire châteaux traded defence for display as the gun made walls obsolete; the ornament is a retired weapon.
Haussmann and the price of land
Paris's uniform façades are a law, not a taste; Haussmann legislated height, line and stone to make the boulevard pay for itself.
The Roman ruins that taught the builders
The Pont du Gard and the arenas of Provence were quarries and textbooks for a thousand years of French building.