Residential and commercial development in the next 25 years will eclipse anything seen in previous generations as the nation moves to accommodate rapid population growth, according to the Brookings Institution.
    
About half the homes, office buildings, stores and factories that will be needed by 2030 don't exist today according to Arther C. Nelson, author of the report for Brookings. The U.S. population is expected to increase 33% to 376 million by 2030, an increase of 94 million than in 2003.
    
To serve that population, almost 60 million housing units will have to be built. About 20 million of these units will replace destroyed or aging homes. In addition, half of the largest metropolitan areas will have to add as much or more commercial and industrial space as existed in 2000. Phenomenal growth in the South and West has turned deserts and soybean fields into cities. These Regions, which face water limitations, will experience the greatest surge in
construction in the next 25 years. If development patterns don't change, subdivisions will continue to sprout on The U.S. will need 59 million new housing units by 2030, 2.2 million per year, farmland farther from metropolitan areas, requiring more roads and sewer lines.
    
For generations, Americans favored single-family homes on larger lots. Development spread to where land was cheaper but within commuting distance to jobs. Communities must decide whether they want to develop policies consistent with those preferences or constrain them. There are signs that people want more choices. Frustration with long commutes is mounting. Downtown housing is enjoying a revival. Even suburbs are creating city-styled town centers that combine stores, offices, condos and townhouses in a walkable environment. But change is coming slowly and we are going to wind up with anywhere between 60% to 70% of development occurring where it always occurred since WWII...on the outer edge.      

Here is a breakdown by State of the current housing units, the number that will be lost and the number of new units needed by the year 2030:
        

   
Using the estimates above, each Housing Unit in the year 2030 will be occupied by an average of 2.4 people, which is approximately the same ratio as today.