Competition for rental housing in the United States is likely to increase as Baby Boomers and other people over the age of 55 decided to move out of their homes, according to Freddie Mac.

Based on the results of a recent survey, Freddie Mac estimated that 6 million homeowners and almost as many renters over the age of 55 will move out of their home and rent their next residence. Of this population, more than 5 million are expected to seek rental housing by 2020.

"When a population this large expects to move into less expensive rental housing, we have to expect it will create significant pressure on both the supply and cost of existing affordable rental housing," said David Brickman, executive vice president of Freddie Mac Multifamily.

The research firm GfK completed 5,914 interviews online between Feb. 10 and 23 to gather information on where people over the age of 55 plan to live in the near future. The survey also asked a series on questions on respondents' financial concerns and retirement plans.

Fifty-one percent of renters over the age of 55 said they preferred renting a home to owning one. Multifamily renters were most likely to express satisfaction, with 60 percent saying they preferred renting to owning.

Thirty-four percent of renters in the survey said they plan to stay in their current home for the rest of their life. However, only 7 percent of retirees who rent say they are currently living in the same home.

Seventy-one percent of respondents who said they plan to move again said they will rent their next home. Of these respondents, 38 percent said their finances will allow them to have enough money to rent comfortably and contribute to savings.

Eighty-three percent of homeowners and 79 percent of renters who plan to rent their next home said they expect it will cost the same or less than their current residence. Sixty percent cited affordability as a "very important" factor in their next move.

Fifty-nine percent of respondents, including 67 percent who currently rent in a multifamily building, said it makes financial sense for someone their age to rent a home. However, 47 percent of renters over the age of 55 said they struggle from paycheck to paycheck. Thirteen percent said they are sometimes not able to afford basic expenses until their next payday.

Convenience was also an important factor affecting the respondents' consideration of renting. Asked to name features that would be very important in choosing their next home, 47 percent named amenities needed for retirement, 44 percent said they would like to live in a community where they are no longer responsible for property upkeep, and 43 percent said they want to live in a walkable community.

Thirty-one percent of renters over the age of 55 said they expect to move to a different neighborhood in the same city, while 23 percent believe they will move to a different property in the same neighborhood. Twenty-four percent expect to move out of state, and 18 percent think they will move to a different city in the same state.

Twenty-four percent of renters said they want to move closer to family members, and 22 percent would like to move closer to children or grandchildren. Eighteen percent were seeking a warmer climate, 17 percent expect to move to a retirement community, and 12 percent think they will move in with one of their adult children.

However, expectations did not always meet reality. While 46 percent of renters said they think they will move closer to family after they retire, but only 31 percent of retired renters had done so. Only 5 percent of retired renters said they have moved in with one of their adult children.