The Delacorte was established by the Public’s founder, Joseph Papp, as a place to bring free Shakespeare to the people. It has since had more than five million visitors and has been home to actors like Meryl Streep, James Earl Jones and Al Pacino.

To date, the Public has done its best to maintain the theater, replacing the wooden stage every three to five years and covering it in the winter with plastic, what amounts to a giant Hefty bag.

The process of reopening the theater for the season begins in February — digging out snow, driving away raccoons, identifying necessary repairs. This dewinterizing process costs about $100,000 a year; the renovation will make the building’s materials more resilient and weatherproof.

In addition to reorganizing the backstage spaces and improving the support systems, Mr. Eustis said he hoped the project would enable the Delacorte to extend its season into the spring and fall.

Right now, the theater has to close after the May-June run of its first production to transition to the second show, which begins in mid-July. The theater also has to cancel three to four performances a summer because of inclement weather, a rate that is expected to increase, given predictions of a warmer, wetter city. Because 95 percent of the theater is in direct sun, the theater is unsuited to matinees. The Public, therefore, is consulting with climatologists and considering ways to make it more hospitable in cold weather. (Heated seats, anyone? A retractable roof?)

“We’re not ruling anything out,” Mr. Eustis said, adding, “nothing that will diminish the experience of sitting in the open air.”