미국에서는 왜 집을 대충 짓나요?

재료비는 생각보다 큰 차이 없네요.
나무 값이 올라거 그런가?

Constructing a concrete house usually costs 5% to 10% more than a wood-framed house. But that gap is closing with rising wood and material prices outpacing the increase in concrete prices. Even at a higher price, concrete has many advantages over wood, including:

https://www.homeadvisor.com/cost/architects-and-engineers/build-concrete-house/#concrete-house-vs-wood-house