The financial resources provided for the renovation of the largest theatre building in Hungary, even based on the most economical technical solutions, did not make a full reconstruction possible, only the improvement of the conditions of opera playing. A considerable part of the transformation took place in the lobby and behind the scenes. The social welfare spaces and changing rooms were extended, the technical equipment of the stage was modernized and the auditorium received an appropriate ventilation system. The new, youthful and convivial interior design of the lobby expresses the original mission of Erkel Theatre opened in 1911 as People’s Opera with the tools of contemporary architecture. By making the auditorium more comfortable, the number of seats reduced from 1935 to 1816, but this is still the theatre building in Hungary seating the most viewers.