In a report titled "These Old Houses: 2001," the Census Bureau said the median value of the 4.5 million detached, owner-occupied housing units built before 1920 was $98,794, compared with $183,502 for the 9.9 million units constructed since 1990. The country's total housing stock in 2001 was 119 million units.

Older buildings offer financial attractions for people with lower incomes. The value of old homes allows more opportunities for home ownership and older properties are often less expensive on a day-to-day basis, based on the figures for monthly housing costs.

But, while the price might be right, many old houses did not have the amenities of the newer homes and their maintenance costs tended to be higher. For example, fewer than 3-in-10 old houses had two or more full bathrooms; but a minimum of two complete baths occurred in nearly 9-in-10 new units. Only 2-in-10 of all older residential units had central air-conditioning installed, while 8-in-10 of all new homes were built with central air or had it installed after the structure was built.

Among homeowners who spend anything on maintenance, those in older units spent an annual median of $509 on housing maintenance, while those in new homes spent $338.

Other report highlights:

The highest concentration of old homes were in the Northeast (nearly 20 percent of the units there), followed by the Midwest (a little more than 10 percent), while the West and South had only about 3 percent each.

In all regions, houses built before 1920 were more likely than new houses to contain more than two floors; and in both the Northeast and Midwest, the majority of old houses had three or more stories.

About 1-in-10 old homes were vacant in 2001; and 1-in-3 of their owners had no plans to market or otherwise occupy them.

About 1-in-4 homeowners in old residences had lived there for at least 32 years.

The data are from the 2001 American Housing Survey National Sample. Statistics from surveys are subject to sampling and nonsampling error.