Tight restrictions on growth are pushing the cost of housing beyond the reach of millions of young families, according to the National Association of Home Builders.

Often disguised as ways to protect the environment or relieve traffic congestion, growth boundaries are pushing people to satellite cities in search of homes that are affordable to middle-income families, says Robert Mitchell, president of the NAHB.

"When large tracts of land are removed from the inventory of developable land because of restrictions in use or the creation of growth boundaries, then the value of all remaining land still available for development increases. That can add thousands and thousands of dollars to the cost of a home," he said.

The cost of a developed lot in some high growth markets has increased from about 25 percent of the total cost of a new home 20 years ago to as much as 35 percent today.