NEW YORK ( MainStreet) — Tougher lending requirements, a transient lifestyle and seeing mortgages throw their parents' finances in turmoil are causing more Millennials to rent instead of buy a home .

"This attitude shift on homeownership and the rise in demand for rentals is directly influencing the growth of private firms looking to fill out real estate portfolios as well as property management groups that have scooped up business from investors who have no interest in the day-to-day of being a landlord," said Don Lawby, president of Real Property Management in Utah.

Some 82% of consumers believe owning a home is a critical part of wealth building but 18% said they are not willing to assume the risk of a mortgage , according to a National Foundation for Credit Counseling (NFCC) survey.

"The unwillingness to take on a mortgage loan may be a smart decision for some , as many borrowers have learned the hard way that homeownership does not come with a guarantee of continually increasing equity," said Gail Cunningham, spokesperson with the NFCC.

The "Generation Rent" phenomenon is not just about younger Americans. As a societal shift has slowly emerged to redefine the American Dream, many older Americans with empty nests are also exploring apartment living.

"Because apartments require less upkeep than a single-family home, they're a natural choice for empty nesters looking to downsize," said David Schwartz, CEO and co-chairman of Chicago-based Waterton Associates LLC, a national apartment investor and operator. "For some, the shift from owning to renting is a permanent one, allowing them to take advantage of the amenity-rich lifestyle offered at many rental communities, while others view an apartment as a temporary home until they figure out their next move, whether it be to a different climate or closer to their children and grandchildren."

For many years, homeownership was a policy objective of the federal government, which symbolized a level of achievement for a person or family but these days many are taking a closer look at whether the costs and benefits of home ownership outperforms the cost of renting.

"People are realizing that coming up with funds and motivation each month for maintenance and up-keep isn't feasible for economic, medical, lifestyle or other reasons," said Dillon Baynes, co-founder and managing partner with Columbia Ventures in Atlanta.

If generation rent continues, a slow down in home sales is bound to have a ripple effect.

"If renting remains a popular choice, it will certainly have an impact on the broader economy starting with the home building industry," said David Reiss, professor with Brooklyn Law School.

"There would be a move away from single-family construction to multi-family."

In the short run, renting can make more financial sense than buying but the downside is that over time rents tend to rise while most mortgages remain fixed.