The National Theatre will be closed for the 1982-83 season to permit the total renovation and redecoration of the historic facility.

The decision was made yesterday by the board of trustees of the New National Theatre Corp. (NNTC) and reversed an earlier plan to limit the construction primarily to summer months over a three-year period. A fully renovated National Theatre will be back in operation by the fall of 1983, according to Harry Teter Jr., the board's president.

The decision will allow Quadrangle-Marriott, the development corporation responsible for renovations, to proceed with remodeling and structural changes that began late in June and that would otherwise have come to a temporary halt this fall. In addition, NNTC will undertake the redecoration of the theater at a cost Teter estimates at "anywhere from $500,000 to $1.5 million.

"We had a temporary season mapped out and we could have reopened the theater this fall, but we realized that it was not a realistic proposition," Teter said. "We would have had to have a trailer out on the sidewalk for a box office, some kind of temporary dressing rooms for the actors, and planking in the lobby, which has been torn up."

He also said that "load-ins" (bringing in scenery and setting it up on stage) would have been greatly complicated. Normally, they are done through a backstage door. Given the current state of construction, however, the scenery would have had to be carried through the lobby and auditorium, adding to the expense of what is already one of the costlier aspects of touring shows.

Initial work on the National has consisted of expanding the street-level lobby and box office, remodeling the restrooms on the mezzanine and installing a new heating and air-conditioning system. During the yearlong close-down, new dressing rooms will be constructed, the lobby off the mezzanine will be expanded and a third lobby will be created off the balcony in what used to be office space. An elevator will also be installed, making all seating levels of the theater accessible to the handicapped.

Under the complex provisions governing the National, NNTC rents the theater for $100,000 a year from Quadrangle-Marriott, which has agreed to abate the rent while the theater is dark. In addition, Quadrangle-Marriott will pay NNTC $175,000 as compensation for the loss of profits it might have earned during the coming season.

The expenses of redecorating and refurbishing the theater, to be borne by NNTC, include new painting, draperies, chandeliers and lighting fixtures, carpeting and some new seats. Plans and drawings should be ready by mid-October, Teter said. The New York-based Shubert Organization, which provides the bookings for the National, has offered to finance the costs of the redecoration, although the offer has yet to be considered by NNTC's board.

"When we're finished, this is going to be a spectacular theater, second to none," Teter said.

The Shuberts, who had a rocky relationship with NNTC's previous president, Maurice B. Tobin, expressed satisfaction with yesterday's decision. "I think it's in the best interest of everyone," said Gerald Schoenfeld, chairman of the Shubert Organization, after the board meeting. "In the long run, it will facilitate the reopening and booking of the theater with the least amount of uncertainty and dark time."

Although there will be no stage shows there during this season, Teter said that the National's outreach programs -- a children's theater and "Noon at the National" -- will continue at other locations, as yet undetermined.

The closing of the National reduces the immediate competition for the entertainment dollar in Washington and is likely to benefit most directly the Kennedy Center and the Warner Theatre. Both of them rely in varying degrees on the Broadway-bound shows and touring companies that have habitually played the National. However, Roger Stevens, the Kennedy Center's chairman, shrugged off the news of the National's closing. "I've always said that I've never considered the Kennedy Center to be in competition with the National," he commented yesterday.

By the time the National reopens, it will have been dark a total of 15 months. The last protracted dark period occurred in 1978, when the theater was closed for 14 weeks due to a lack of bookings.