A planning application is set to be submitted for the long-awaited transformation of the Old Magnus Buildings, Newark, into the National Centre for Civil War Learning.
The plans include a modern, glass-fronted structure which would be added to the unoccupied buildings that were home to the original Magnus Grammar School on Appletongate.
The project development manager, Mrs Briony Robins, said the modern structure would add to the architectural heritage of the site, which includes the Tudor Hall, dating from 1529, plus a Georgian townhouse and Victorian schoolroom.
As part of the plans all three of the older buildings would be extensively restored and facilities for permanent and temporary exhibitions incorporated.
The Tudor Hall, which would be restored to its original colour scheme, could be a study area, meeting space and café.
Mrs Robins said the museum could bring an extra 26,000 visitors to Newark and the surrounding area, potentially drawing in up to £1m a year to the local economy.
In July, Newark and Sherwood District Council’s museums service commissioned concept drawings of how the interior could look.
The project is dependent on a successful bid for £2.8m to the Heritage Lottery Fund.
The plans will be submitted to the district council’s planning department.
If they are approved the development, which will cost in excess of £4m, could be open by 2014.
The museum would need more than 60 volunteers to help run it.
Mrs Robins said: “This is more than just building a new museum. It is about creating a new community resource for learning.
“This venture will bring lots more visitors to Newark and Sherwood.
“We want to promote the historical significance of Newark because it is very undervalued.”
The Heritage Lottery Fund previously granted development money, which helped to pay for preliminary investigations and remedial works.