A Royal Shakespeare Company (RSC) revamp will see Stratford's Swan Theatre close for two years.
The Swan Theatre is joined to the Royal Shakespeare Theatre
A rebuild of the Royal Shakespeare Theatre (RST) means a temporary building will be used for three years.
But its impact on the adjoining Swan Theatre is only just being made known to the public. Both theatres will be closed for two summers.
The RSC said it was always the plan for the Swan to close "for some significant time" during redevelopment.
A meeting of the Stratford Community Forum, set up by the RSC to talk with residents and traders, heard the Swan will close in 2008.
Locals said they were unaware of a two-season closure and there are claims the town could lose millions of pounds of tourism spending, greater than first thought.
Royal Shakespeare Theatre (RST): Closes in 2007 as a 1,443-seat venue, reopens in 2010 with 1,000 seats
Swan Theatre: Closes for 2008 and 2009, then reopens unchanged
Courtyard Theatre: Opens in summer 2006 and closes when the new RST opens
The Other Place (TOP): will act as a foyer for the Courtyard Theatre and reopen as a small studio when all works are complete
While the RST is closed, the temporary Courtyard Theatre, with about 1,000 seats will be used.
Vikki Heywood, RSC executive director, said: "We have always said that the Swan will close during the transformation but our commitment has always been to continue performing in the town.
"We made it clear at the Forum last week that we'll supplement the Courtyard programme during transition and the plan for this will be ready by the summer. Until then, any judge on the economic impact to the town is a wild guess.
"The number of theatre seats is only one factor in keeping visitor numbers up during the project.
"Visitors don't only come to the town for the theatre. We need to work together to make sure there's still a buzz about the town while we're transforming the theatres."
The RSC said the closure of the Swan Theatre was mentioned at the Town Management Partnership last October, with the mayor and 60 business leaders were present.