$25 trillion in next 25 years

In the past three centuries over 300 billion square feet homes, factories, offices, and other structures have been built in the United States. According to new studies done by Virginia Tech urban planning professor Robert Lang, it will take 25 short years to erect the next 200 billion square feet, which will need to accomodate all the losses caused by the recent hurricanes. As a result of this real estate boom $25 trillion will need to be spent, which is more than twice the size of the American economy today. The bulk of this building will be done in 10 major metro regions that he has christened "megapolitans."
In the end is it worth spending all this money on these buildings? What consequences (negative or positive) will result in this boom?