BARNSTABLE — The percentage of Cape Cod’s housing stock being used as second homes is increasing, and it’s having a significant impact — good and bad — on the region.

That is the gist of the recently released Cape Cod Second Homeowners report from the Cape Cod Commission and the University of Massachusetts’ Donahue Institute.

The 50-page report was commissioned to determine how second homes are being used, whether owners planned to eventually convert them to a primary year-round residence and how these property owners contribute to the local economy, according to Leslie Richardson, chief economic officer of the Cape Cod Commission.

Approximately 58,500 of Cape Cod’s nearly 160,000 homes — about 37 percent — are now being used seasonally, according to the report. This represents a jump of nearly 6,500 second homes on the Cape since a similar report was issued by the commission in 2008.

“It appears that there has been an increase in second-home owners on the Cape in the decade following the recession,” said Richardson, suggesting buyers entered an attractively priced market for investment purposes.

But it hasn't always been that way.

As the Cape’s year-round population boomed in the 1970s, 1980s and 1990s, the percentage of properties used as second homes declined, but that trend is now being reversed.

“We have maintained between a 30 to 45 percentage of second homes over the past few decades,” Richardson said.

The high rate of second-home ownership reduces the number of housing options available to year-round residents and workers, especially since the properties are rarely rented, and if so, only in the lucrative summer months.

“Winter rentals are helpful, but it doesn’t solve the (affordable year-round rental) problem,” Richardson said.

A larger concern, she says, is that the Cape, under current zoning regulations, is nearly built out, which will increase property values as demand for second homes continues to rise, making the region even less affordable.

“This has me very concerned,” said Jay Coburn, chief executive officer of the Community Development Partnership in Eastham. “Where’s the workforce going to live? Second-home owners who have significant investments here should be worried about this, too.”

On the bright side, the report finds that nearly all the Cape’s second-home owners buy groceries and hardware, building and garden supplies here and use local construction and landscaping services. They were less likely to use banking and medical services, preferring to leverage established relationships off-Cape, the study found.

“There was a difference of opinion about the value of second homeowners on the local economy,” Richardson said. “Are they buying things off-Cape and bringing them here, or are they shopping here?”

The study also revealed the second-home owner population significantly contributes to local arts, culture, nonprofit and charitable organizations.

Nearly 20 percent of the almost 1,300 second-home owners studied in the report plan on converting the home to a primary residence, which translates to 11,000 more year-round homes and 20,000 more people on the Cape in the next 20 years.

Richardson found this statistic “interesting,” and a valuable piece of data for population and service need planning.

“Retirees should be thinking about who is going to provide their healthcare and other services,” said Coburn, advocating for the need for zoning reform in the region.

Nearly 40 percent of those homeowners, with an average age in the 60s, intend to continue working after moving here full time, many for off-Cape businesses, according to the report.

“This could be reflective that people lost wealth during the recession and need to keep working,” said Richardson.

— Follow Geoff Spillane on Twitter: @GSpillaneCCT.