As planning for Allston begins to enter a more concrete stage this year, the University is preparing to pull in resources from a variety of sources.

The central administration has already begun taxing the endowment, at a rate of one-half of 1 percent per year, for an infrastructure fund which will finance land acquisition, construction and other costs associated with the expansion in Allston. The tax, begun in early 2001 and slated to last 25 years, should produce at least $3 billion in revenue—or potentially far more if the endowment continues its climb.

Gifts to the University are expected to provide further income, though administrators interviewed in the past month appeared to have differing views on how large a role Allston would play in the capital campaign that Harvard will launch in the next few years.

Berman said Allston was not “at the top” of priorities for the campaign, but Donella Rapier, vice president for alumni affairs and development, wrote in an e-mail that “Allston-related initiatives will be among our top priorities during the next campaign and well beyond.”

In the interview last month, Summers would say only, “It certainly seems that Allston will figure in the next campaign.”

The University, which boasts of an industry-leading AAA credit rating, could also assume considerable debt in financing its projects in Allston.

And in what Berman has described as a last resort, the University could consider decapitalizing the endowment, or withdrawing funds beyond the standard payout, to provide still further income for the expansion.

But Summers said last month that decapitalizing would not be necessary to pay for Allston.

“It would be wrong to say that that’s an option we’ve been looking for,” he said.

—Nicholas M. Ciarelli contributed to the reporting of this story.

—Staff writer Zachary M. Seward can be reached at seward@fas.harvard.edu.