The Ridley-Tree Cancer Center in Santa Barbara will soon be home to a new linear accelerator, high-tech cancer fighting device.

The Santa Barbara Planning Commission on Thursday gave its unanimous approval to revisions on a project originally approved in 2010. The vote was 6-0, with commissioner Gabe Escobedo absent.

The changes include building a 2,107-square-foot addition to the main Cancer Center building at 540 W. Pueblo St. to house a third linear accelerator, a device that uses external beam radiation to treat patients with cancer. The structure will include additional office space.

As part of the project, the Cancer Center also proposed eliminating a new duplex at 521 W. Junipero St., intended for employee housing, to build a six-space parking lot.

“The Cancer Center has been suffering from a glut of patients requiring radiation oncology,” said the project’s architect, Brian Cearnal of the Cearnal Collective.

“The reality is they have limited resources and their No. 1 objective is to treat cancer patients. So building the housing is a very expensive proposition.”

Losing the duplex’s two housing units was unfortunate, he added, but he said the Cancer Foundation of Santa Barbara, the property owner, feels “it is money they just do not have right now to spend on that housing.”

The Cancer Center project includes two other duplexes, but Cearnal noted there’s a great need for parking in the area, which is two blocks from Santa Barbara Cottage Hospital.

“It is just a hard choice that the Cancer Center had to make, and they prioritized the vault over the housing,” he said.

Planning commissioner Devon Wardlow asked Cearnal if the Cancer Center had worked with the Housing Authority of the City of Santa Barbara or other organizations to find a way to build the duplex units.

“No, we did not, I confess, because it was just really, a matter of cost,” replied Cearnal, adding that the only way to keep the housing would have been to build it on top of the parking area — a prohibitive expense.

The project, which encompasses the parcels at 540 W. Pueblo and 521 W. Junipero streets, includes a wall between the site and the nearby Oaks Parent-Child Workshop at 605 W. Junipero St. The wall is intended primarily to help block noise and dust during construction.

The Ridley-Tree Cancer Center has provided cancer care treatment for more than 70 years and serves as a regional destination for oncology services.

Despite the loss of the housing units, planning commissioners were supportive of the additions.

“I think this is a worthy project,” commissioner Lesley Wiscomb said.

The new linear accelerator, she said, “really serves our community.”

A medical linear accelerator customizes high energy X-rays or electrons to conform to a tumor’s shape and destroy cancer cells while sparing surrounding normal tissue, according to radiologyinfo.org.

The Planning Commission added a condition, at Wiscomb’s request, that construction crews not park on the street.

“That area is highly impacted, it’s hard to park there …,” she said. “It just helps an already impacted area.”