Average new home size gets smaller, more first-time and over 55 buyers.

Data recently released by the National Association of Home Builders (NAHB) found the average size of a new home that was completed in 2009 fell to 2,480 square feet from 2,520 square feet in 2008. The last time the average completed-home size fell by a statistically significant amount was 1982.

Two other trends in home construction are contributing to the declining square footages: The prominence of first-time buyers in the housing market and the increasing number of households with members 55 and older who are buying homes.

First-time buyers, driven into the market in good part by the availability of an $8,000 tax credit, are more likely to compromise on home size in exchange for a lower price. And the 55-plus crowd tends to purchase single-story homes, which generally are smaller because of the land costs that favor the more-efficient two-story plans.

Members… Don’t forget to use the First-Time Home Buyer-Friendly Seal!