Derby Museum and Art Gallery wants to expand into the neighbouring Central Library, when the library is moved to the council house.
The plans would see the Museum and Art Gallery hold corporate events there while the Silk Mill is being redeveloped. This would include events like weddings.
Tony Butler, the museum's executive director, said: "It [Central Library] is going to have public use, it is not going to be thrown to the private sector.
"It will also have a commercial use that will then help us cover the running costs of it...the profits also add to our resilience by helping us generate more earned income."