You've redefined "house" to "mansion" in order to reach your conclusion. There are plenty of places in the world where people build their own houses and live in them quite happily.

A farmer builds up a flock of sheep or a herd of cows, and everyone in the village is richer. A miller builds a water mill and everyone in the village gets bread. A blacksmith builds a forge and everyone in the village now has access to metal items.

Wealth is not a zero-sum game.