Over one million condominiums were sold in 2004, and the nation's housing is looking at a startling new ratio -- the number of condo sales to conventional single family sales was about one to seven, according to a US Census annual housing survey.

There are about 15 single-family dwellings to every condo, but buyers are pouring into condominiums, presumably for the lock-and-go, low-maintenance lifestyle they promote.

Celia Chen, an economist for Economy.com told American Demographics that condominium prices have now shot above those of single-family homes. From September 2004 to September 2005, condo prices shot up nine percent to $213,600.

Clearly, people aren't buying them because they are cheaper. It's a lifestyle choice, and pundits believe that they'll only become more popular, particularly with older residents.

From 2005 to 2015, American Demographics projects that all owner-occupied households of ages 55 to 74 will rise 36 percent, an increase of over 8 million older homeowners.

According to a 2005 Del Webb survey, 45 percent of "active adults" (those aged 59-70) plan to move upon retirement. The number one reason they cite for moving is that they "want a home with less maintenance."

Pam O'Connor, CEO of Leading Real Estate Companies of the World(TM), says there are several reasons why condos sales are up, including their use as "vacation/event homes, commuter homes, college campus substitute housing, pied-à-terre's, and investments."

So what is a condominium? It's a cooperative form of ownership in which homeowners "join with each other on a democratic basis to own or control the housing and/or related community facilities in which they live," defines the National Association of Housing Cooperatives.

A condominium owner actually owns part of the building and land (their own unit and a pro-rata share of the common property,) while in a "co-op" the owner owns a part interest in a cooperative that operates the building and land.

A homeowner's association manages and maintains the common areas and dues can also pay for some or all utility bills, trash removal, snow shoveling, window-cleaning, and whatever else the HOA members agree upon.

Condos are ideal properties for the mixed-use trend in city planning and redevelopment -- the concept that people can live and work in the same area, walk to the grocery and park, and generally build a neighborhood that is supported by both commercial and residential interests. A Wall Street Journal report November 28, 2005 noted that mixed-use development is "all the rage." The report cited real estate research firms Property & Portfolio Research and Reed Construction Data as finding that "21.6 percent of all new construction this year will be mixed use, compared with 17.5 percent in 2002."

The nation's largest builders are changing their business models to build more multi-family housing for purchase. D R Horton built only single-family detached homes until 1996. Today, condos and townhomes are over 17 percent of the company's business, and it expects to build more in the future, according to a Wall Street Journal report in December 2005.

The Coldwell Banker organization has gathered average condominium prices from all over the country and the world to find that third quarter 2005 prices are hefty indeed. These are the average snapshot prices for condominium apartments 1,400 square feet in size, featuring two bedrooms and two and one-half bathrooms, in buildings with at least 10 stories and a doorman:

• New York, New York: $1,448,000

• Boston, Massachusetts: $981,250

• San Francisco, California: $975,500

• Seattle, Washington: $712,000

• Los Angeles, California: $674,000

• Atlanta, Georgia: $589,750

• Philadelphia, Pennsylvania: $582,500

• Washington, D.C.: $569,475

• Chicago, Illinois: $467,375

• Miami, Florida: $443,750

In its America's Housing projection for 2010, the National Association of Home Builders said that housing will look approximately the same as it does now, but there will be more amenities than ever before:

New homes are projected to have:

• 2,200 or more square feet

• three or more bedrooms

• two and a half bathrooms

• garage for two or more cars

• energy efficient heating and cooling systems

• more steel, concrete, engineered wood, and recycled products

• convertible interior designs to appeal to a variety of homebuyers

• high-speed data access, modular wiring and controls, multiple phone lines

• security systems

• neighborhoods with smaller lots, narrower streets, less pavement

• more mixed-use communities

• $270,00-$280,000 price tags

What wasn't predicted was how many of these homes will be condos versus single family.