AURORA | Rents in Colorado climbed about 6 percent last year, almost twice the national average.

Those surging rental rates made purchasing apartment complexes an especially-attractive option for investors last year.

In Aurora alone, at least five multi-million-dollar complexes sold last year, sales that experts say likely had a lot to do with rental rates that haven’t shown any sign of slowing their growth.

In Aurora, rents grew 8 percent last year to an average of $1,380 for a two-bedroom apartment, according to

University of Denver professor Ron Throupe said that while some newer buildings are built by “merchant builders” who plan to sell the building quickly after they complete construction, many of the recent sales are a product of climbing rents.

Throupe, who teaches at DU’s Franklin L. Burns School of Real Estate and Construction Management, said when buyers do the financial analysis on an apartment building, what jumps out at them are high rent rates that are trending upward.

Wood Partners, an Atlanta-based developer and property management firm, is one of several to jump into the Aurora market in recent years. In January the company announced it had purchased the 420-unit The Grove at City Center complex near East Alameda Avenue and Interstate 225.

Terms of the deal weren’t disclosed, but similarly sized projects — including the Liberty Creek Apartments and Aurora Meadows — sold for more than $60 million last year.

Jane Maushardt, Wood Partners’ senior vice president of acquisition, said there were a variety of factors that made The Grove at City Center attractive for the company, including its proximity to a soon-to-open light rail stop.

Rents also play a role, especially when Wood Partners looks at suburban markets like Aurora, she said.

“Escalating core rents have driven renters to look for attractive, more affordable living options in the suburban markets, allowing owners to upgrade older properties to meet this demand. This opportunity has not been lost on many, making the value-add space very competitive,” she said in an email this week.

Wood also purchased and then sold the Del Arte apartment complex in Aurora last year.

In July, Santa Barbara, Calif.-based Granite Peak Partners Inc. announced it sold two Aurora properties totaling 664 units for $91 million.

The complexes, Hearthstone at City Center, comprised of 360 apartment homes, sold for $53.4 million and Bella Terra at City Center, which has 304 apartments, sold for $37.6 million.

When Granite Peak announced the sales, the company said in a statement that the 30-year-old complexes had seen substantial revenue growth in recent years and rents that climbed to more than $1,100 at Hearthstone for a one-bedroom and $1,175 at Bella Terra for a two-bedroom unit.

Operating income jumped 240 percent in the eight years before the properties sold, Granite Peak said.

Throupe said that while sales of apartment complexes have been common in the past year, the purchases haven’t meant a dip in new construction.

“It hasn’t slowed,” he said. “There are plenty of apartments that are still being built now.”

The issue on that front, Throupe said, is that there might not be enough labor to handle the number of projects developers are hoping to complete.

As for rents, Throupe said they haven’t shown any sign of leveling off or dropping, but at some point the growth in rental rates will have to slow down. Some areas have seen 10 percent growth in a single year, and he said that trend won’t last.

“The clip of 10 percent a year is hard to sustain,” he said.