London's National Theatre has submitted a planning application for a £70m facelift for its Grade II listed home.
Theatre director Nicholas Hytner said he wanted "to open our building up to audiences, passers-by and the local community".
If Lambeth Council gives the go-ahead this autumn, work is due to start by early 2012, dependent upon fundraising.
The theatre, situated on the Thames in central London, hopes some of the development will be completed by 2013.
However, a theatre spokeswoman could not say when the project would be finished.
The theatre hopes to raise £50m from the private sector and £20m from other sources like the the National Lottery.
The design, by architects Haworth Tompkins, includes plans to refurbish the theatre on all sides, drawing more people in with green spaces and gardens.
The building will also feature a new education centre, allowing an extra 50,000 people a year to engage in learning and training activities at the theatre.
Plans also include a new glass-fronted production building at the south of the theatre, including a paint studio offering passers-by views of set artists at work.
Mr Hytner added the building would "break down the National's walls" and "contribute to the regeneration of the South Bank".
The National Theatre, designed by Denys Lasdun, opened in 1976.
It was designed to realise the vision described by English actor and playwright Harley Granville-Barker, who in 1904 foresaw a "visibly and unmistakably popular institution making a large appeal to the whole community".