If we ask a child to draw a house, a triangular silhouette will almost certainly appear, with two sloped planes meeting at a ridge. Few architectural forms are as universally recognizable as the pitched-roof house. From a semiotic perspective, this elemental image functions as a condensed sign of shelter that, in just a few traces, synthesizes protection, interiority, and belonging. What we now read as a universal symbol, however, emerged from a concrete necessity. From Alpine chalets shedding snow to Mediterranean roof tiles mitigating summer heat, the slope responded to climate and construction challenges long before it became an aesthetic code.