A sweeping transformation of Palo Alto's Buena Vista Mobile Home Park, including the replacement of all 103 mobile homes and 12 studio apartments with new units and other park upgrades, could cost upwards of $30 million, according to the organizations newly in charge of the park.

Park operator Caritas Communities, which was brought in after the Santa Clara County Housing Authority purchased the 4-acre El Camino Real site last fall, told nearly 50 park residents about the proposed four-year redevelopment at a meeting on March 2.

It is the first time that the scope of the plans has been made public since the Housing Authority bought Buena Vista for $40.4 million, using $14.5 million each from the city of Palo Alto and Santa Clara County and $26 million from the U.S. Department of Housing and Urban Development (HUD).

In addition to new homes for the residents, the renovation will include upgrading gas-line infrastructure, eliminating blight and vermin and adding social and health programs to benefit the low-income and largely immigrant population of about 400 residents.

Staff of Caritas, an Irvine-based nonprofit organization, unveiled its timeline for the redevelopment at the meeting:

• Gas-line repairs, March-May.

• New lease agreements signed through May.

• Architect selection in June.

• Site design from June 2018-March 2019.

• Construction design through December 2019.

• New-home construction from January 2020 to December 2021.

"All current homes will be moved off-site. Everyone will get a new home," Chief Operating Officer Tracy Bejotte told the residents. She added that the homes will be mobile units and not apartments or single-family homes. The studio apartments, built in the 1950s, will be demolished and replaced with mobile homes, she said in a follow-up email.

Caritas doesn't have an estimated cost for the replacements, nor a fixed idea of what they will look like, she said. Much depends on the appraisals of the existing units and the funding that is yet to be secured.

Katherine Harasz, executive director of the Santa Clara County Housing Authority, said county officials had only "a ballpark guess" for the total cost of infrastructure improvements.

"We thought it could go as high as $30 million," she said, including the relocation of residents during construction, payment of federally required local prevailing wages for laborers and mechanics, and construction costs in the currently hot market.

The $30 million redevelopment estimate, in addition to the $40.4 million land price, pencils out to approximately $609,000 for each of the 115 units. In comparison, the median value of a single-family home in Palo Alto as of Jan. 31 was $3.1 million, according to the online real estate website Zillow. In East Palo Alto, the median was $907,000.

"We took on this project not because we had all the answers but because it was the right thing to do and we felt we had the skill and support to get the answers," Harasz stated in an email.

"We have $14.5 million in county funds set aside for upgrades. We expect we'll need more, and Caritas will likely approach the need in the same way most affordable housing developers do: They will look around for available sources at the time, determine what the best terms are and apply for those funds," she said.

Funding sources could include government, private and nonprofit monies and bonds.

Harasz said residents would be temporarily relocated during construction. That "adds cost to the project and is disruptive to working families, students and anyone who may be mobility impaired," she acknowledged. For that reason, she added, "It is our best judgment not to increase or replace the population at the park until the rehabilitation is complete."

Bejotte said that Caritas will look at whether any more renters could be added after construction is complete. The rent for existing residents would not be raised for at least three years, after which an increase might be necessary, she said.

Caritas' Chief Investment Officer John Woolley has reiterated Caritas' commitment to keeping the park affordable for low-income residents, even as he admitted the agency is "quite a way away from understanding solutions on how to keep the park affordable when the newer homes come in."

How that will be achieved depends on how much funding Caritas can obtain, the appraised value of the existing units and other factors and costs. Bejotte said Caritas is exploring a number of funding options, including grants and bond financing.

Even as the nonprofit works on its ambitious redevelopment plan, residents have already seen significant changes at the park.

Caritas is funding the repairs of existing homes to bring them up to HUD standards; about half of the repairs have been completed, Chief Mission Officer Thomas Mauro said.

The organization has also put an end to much of the drug dealing that was taking place, although staff said more must be done to eradicate the problem. The park now has security and a pest-control service and an attentive on-site manager, Mauro said. There is an afterschool homework club, and a dental-services van recently came to the park.

Depending on the park's reconfiguration, Caritas will look at the possibility of adding a small park and other amenities that residents said they want.

Caritas is also moving forward with a zero-tolerance policy for abandoned and inoperable vehicles, in part because parking space is limited. Woolley said the park cannot accommodate four or five vehicles per household. Currently, there are not even enough spaces for two cars per unit, he said.

"It's a universal problem. This has nothing to do with Palo Alto. It's just life today," he said.

Currently, the park is operating under the rules put in place by the previous owners. But Caritas is also working with the Buena Vista Park Residents Association to develop new rules for parking, trash, noise levels, loose animals, unattended children, parties and other conditions. Those regulations will be presented to all residents for discussion, as some of the new changes might be difficult for residents to accept -- particularly about parking and vehicle storage.

Erika Escalante, board president of the residents association, said she is pleased with the progress taking place.

"I feel like we are doing good work. Caritas is very inclusive and not just coming to impose their rules. I feel pretty good about the future."