Preston-based architecture and planning consultancy Cassidy + Ashton has submitted proposals for a £1m refurbishment of the grade-2* listed Grand Theatre in Blackpool.
Internal alterations include reconfiguring the ground floor foyer to maximise available space, with a new box office and improved wheelchair access to the main auditorium.
A staircase off Church Street will provide access to the first and second floor levels, and there will be a reconfiguration of some of the dressing rooms to allow for a new rehearsal space.
The project will rationalise the theatre's office accommodation, bringing together staff facilities which at present are spread throughout the building.
The plans were submitted on behalf of the Blackpool Grand Theatre Trust.
The Grand Theatre has a capacity of 1,053 seats within a four-tier auditorium.
Lawrence McBurney, associate architect at Cassidy + Ashton, said: "The Grand Theatre is one of only a handful of listed buildings in Blackpool and we're determined to preserve its considerable historic importance to the town.
"It's an honour to work on such a key heritage asset with our designs helping to rationalise the changing space, which has been altered over the years, to maximise usability of the theatre to create a more enjoyable experience for future generations of staff, performers and audiences alike."
Parkinson's is the appointed contractor. If planning permission is received, work is due to start on site in 2015 with completion expected in July.