In two to three weeks the Brattle Theatre will commence the most extensive renovation program it has undertaken since the building became a movie theatre in 1953. The Brattle management last night asured "patrons and fans of the 100-year-old building that it does not plan to turn it into a cold, glossy modern structure of plate glass and steel, but will retain the building's old-fashioned charm."

Mrs. Joyce Pratt, manager of the Brattle, said that no increase in price for movie tickets or refreshments downstairs was envisioned. The greatest changes will be downstairs, where the lobby next to the Blue Parrot will be made three times as large and the passageway to the Casablanca will be three feet wider, the new lobby will be paneled, and the entire downstairs floor covered with wall-to-wall carpeting.