Shelter Stats Today's newly built homes are substantially larger and packed with more amenities than their predecessors of 30 years ago, according to annual data on new-home characteristics released by the U.S. Census Bureau in June. The statistics, along with NAHB research on several additional trends, provide a snapshot of changing aspects of home design over the past three decades, including the continued expansion of new-home size through 2005: The average floor area in a newly built home last year reached an all-time high of 2,434 square feet—up from an average of 1,645 square feet in 1975.

One thing that has shrunk over the years is lot size, which data show has dropped from a median of 10,000 square feet in 1990 to 8,500 square feet today. But because of the rising cost of developed lots, the share of home price that can be attributed to the lot on which the home is built hasn't changed; it's still about 25 percent.

Other important trends include the following:

  • Between 1975 and 2005, the percentage of homes built with central AC went from 46 percent to 89 percent.
  • The greatest percentage of new homes are still built with three bedrooms, but the percentage of homes built with four or more bedrooms has risen steadily, from 21 percent in 1975 to 39 percent in 2005.
  • The percentage of newly built homes with garages for three or more cars doubled between 1991 and 2005, reaching 20 percent last year.
  • “Characteristics of New Housing 2005” is available online at Additional information is available at stats under “Selected Characteristics of New Housing.”

    Tax Figures A recent study by the NAHB provides an in-depth analysis of the nationwide use of the mortgage interest and real estate deductions. Using the most recent IRS data available, the NAHB determined that for the 35 million taxpayers who used the home mortgage deduction in 2003, the average amount of mortgage interest deducted was $9,650. For the 39 million who deducted real estate taxes in 2003, the average was more than $3,000.

    Higher mortgage interest deductions occurred in areas with rapidly growing populations and high house prices. California posted the highest average among all states, at approximately $14,000 per taxpayer. The top six congressional districts in terms of cumulative mortgage interest totaled more than $15.5 billion and were located in the Golden State. The five congressional districts with the least mortgage interest deducted were located in the New York City metropolitan area, where renters exceed the number of homeowners.

    For more information on this report, go to

    Green House The National Housing Center, headquarters for the NAHB, has earned a 2006 Energy Star designation for its focus on conserving natural resources while providing a comfortable, healthy environment for employees and visitors. It also meets Energy Star requirements for all indoor environment criteria. The NAHB integrated energy-efficient features during a major renovation and expansion of the building—constructed in 1972—five years ago.