A Boston-based developer credits a new federal program for helping it renovate a Yarmouth affordable-housing complex under an unusually fast schedule.

Weston Assoc. took just six months to complete $6 million in upgrades to 150 apartments at Swan Pond Village, which wrapped up in June.

Weston Assoc. acquired the 34-year-old complex, which had never been renovated, for $12.6 million in 2010 but couldn’t go ahead with the building upgrades because of the difficulties of obtaining tax credits from private investors while waiting to close on loans from government sources.

"They’re Wall Street types and they don’t want to hang around, they want to move quickly," said Michael Packard, vice president of operations at Weston Assoc.

Weston used HUD’s 223f pilot program that provided it with faster access to $23.5 million in long-term FHA financing. The financing package also included $18 million in tax-exempt bonds from MassDevelopment and $10 million in low-income housing tax credits from the Massachusetts Department of Housing and Community Development.

The project included new roofs, windows, interiors, bathrooms, HVAC systems and electrical upgrades. It took about a week to upgrade each unit, with residents given access to a model unit while work was being done.

"They never have to leave and at the end of the week they end up with a brand new apartment," Packard said.

The project was only the fourth in the nation to utilize the HUD pilot program. Packard said Weston plans to use it again as it acquires and renovates multi-family properties around New England. The company owns 22 properties.

"The beauty of it was we were able to close a deal quickly and do a significant amount of property of rehab to the property," he said.