From commercial storefronts to music practice rooms, Yale will have to build much more than just two new residential colleges if the University decides to expand the undergraduate enrollment, a report to be released next week concludes.

The long-awaited document will recommend administrators take more than a dozen steps to ensure the proposed expansion does not change Yale for the worse. Nearly a year in the making, the report was drafted by two committees of faculty, staff and students convened to examine the academic and student-life implications of growing from 12 to 14 colleges.

While the report is expected to remain confidential until it is finalized and distributed to Corporation members — who will review it Feb. 22 — committee officials shared some of its contents with the News on Wednesday.

“There was no up-or-down vote,” said former Calhoun College Master William Sledge, chairman of the student life committee. “What we did,” he continued, “is we identified areas that are either problematic now or will be problematic if there is an expansion, and we recommended approaches to solving or strengthening those areas.”

The question now, Sledge said, is whether the University will conclude that it can afford to make the necessary financial investment in all the areas that need attention.

The report will emphasize three areas — campuswide issues, extracurricular issues and academic resources, committee members said. The two committees concluded that, in order for Yale to proceed with a successful expansion, the University must be prepared to invest the resources necessary to prevent marginalization of the students living in the new colleges and to guarantee the rest of campus does not suffer from an influx of about 600 students.

A paramount concern addressed in the report is the colleges’ proposed location, behind the Grove Street Cemetery along Prospect Street — a site administrators have long described as non-negotiable.

And while students expressed significant reservations about the site in their feedback to the committee, Sledge said “there is a certain amount of confidence” that the problems of isolation and inaccessibility vis-a-vis the location can be solved through the measures suggested in the report.

Those recommendations include bolstering Yale’s transportation system and making it more student-friendly by adding smaller buses as well as by enhancing physical pathways in the area of the new colleges to better link Science Hill with the rest of campus. Such changes could include turning the Farmington Canal into a pedestrian walk, beautifying Ashmun and Canal streets so students are more inclined to access the site of the colleges from by means of the Swing Space and Payne Whitney Gymnasium area, and adding retail or commercial space to the first floor of the Becton Center or another nearby building.

That last idea was suggested to the committee by an undergraduate in attendance at one of the forums held this fall to discuss the possible expansion. Its inclusion in the report was cited by committee members as perhaps the best example of how one idea from a student could end up making a significant difference in how the planning for the new colleges unfolds.

“We got more and more excited about how the function of these colleges is to enliven a part of the University that’s kind of there, as the students call it, as ‘the day campus,’” Sledge said. “It creates a sort of odd statement with us putting so much emphasis on the sciences … [But] this has the option to make Science Hill a more integrated part of the campus, and I think that’s part of what’s very appealing.”

Another significant recommendation for drawing students toward the Science Hill area — especially on nights and weekends — will be the construction of a so-called “third building” alongside the two new colleges, which administrators have said could be a student center or a classroom building like William L. Harkness Hall.

In addition to classrooms, the committee broadly recommended the building contain music practice rooms or theatrical rehearsal performance space and office space for student organizations.

It is unlikely that the site would contain a fitness center, according to committee members. The new colleges would create a need for more workout space, but that need is expected to be filled by a new, massive fitness center inside the Sterling Chemistry Laboratory further north on Science Hill.

The planned gym, which could include a juice bar, was first reported in a News article in November, which cited anonymous sources, and the project has never been publicly announced. But committee members said they were briefed on the planned gym and decided not to recommend workout space in the third building as a result.

The report will also call for a significant investment in hiring additional faculty members for specific departments in which courses are already over-enrolled, including political science and English, in order to compensate for a larger undergraduate population.

Among those stress points are freshman English classes and writing classes in general, introductory lectures in fields ranging from chemistry to economics, junior seminars in popular majors like political science and language classes.

The chairman of the committee on academic resources and Dean of Undergraduate Education Joe Gordon declined to comment in advance of the report’s release, which will come sometime early next week, said Associate Dean of Yale College Penelope Laurans, a special assistant to University President Richard Levin.

Levin confirmed to the News on Tuesday that he does plan to release the report in advance of the Corporation meeting. The study is in the process of being finalized and prepared for mailing to the Corporation members, he said.

In advance of that, Levin declined to speak at length about his opinion of the report, or about the document’s contents.

“All I would say is I think it’s very thoughtful and very thorough,” Levin said in a telephone interview. “The committees have done a great service.”

The Corporation is expected to vote Feb. 22 on whether to proceed with planning for expanding Yale College. As it stands now, the proposed enlargement of the school would boost the undergraduate enrollment by 10 percent, to about 6,000, and include the construction of two residential colleges, the first new ones to be erected since Morse and Ezra Stiles colleges were built in the 1960s.

Overall, the two new colleges are estimated to cost at least $600 million, making them the most expensive residence halls, by no small margin, ever to be built at Yale or any other university in the United States.