When the Federal Reserve artificially reduces interest rates below their free-market level, it sends a false message to entrepreneurs. Firms begin expanding as if consumers have increased their savings, but in fact consumers have reduced their savings (due to the lower interest rates). Businesses that churn out durable goods, such as furnaces, cargo ships, and, yes, houses will find business booming, because these sectors respond positively to low interest rates. On the other hand, other sectors don't need to contract, because (unlike the scenario of genuine savings) nobody is cutting back on consumption. This is precisely why the Fed-induced boom is unsustainable — real resources have not been released from consumer sectors in order to fuel the expansion of the capital sectors.