UK-based Haworth Tompkins has submitted plans to the local council to revamp the National Theatre in London, UK.
The scheme, worth £70m ($103m), will improve access to the Grade II-listed building and create a cafe, rooftop garden and a workshop.
A new visitor centre will be added to the Cottesloe Theatre's entrance and a walkway will allow visitors to access the Cottesloe and Lyttelton Theatres.
The project will also involve building a four-storey workshop featuring aluminium mullions and a glazed ground-floor plinth.
Lambeth Council is expected to announce its decision this year.