A design team has been appointed to carry out a feasibility study into major modernisation works on Birmingham's Council House and redevelopment of Birmingham Museum & Art Gallery.
The Grade II*-listed complex, which comprises the Council House built in 1879 and an extension from 1911, requires major improvements, in particular the upgrade of its electrical and mechanical installations.
There are also plans for an overhaul of the museum element of the complex in Victoria Square.
Birmingham Museums Trust will work with community groups and experts to rethink the city's collection and showcase it in new ways aimed at attracting young, multicultural audiences and international visitors to the city.
First unveiled late last year, the plan is to create new displays and exhibitions including a children's museum, community gallery and larger learning suite.
Birmingham City Council has appointed contractor Bouygues and a design team led by city practice Associated Architects to carry out the study looking at how the works should be carried out.
Also working on the scheme are conservation architects Rodney Melville & Partners and Hoare Lea M&E Engineers.
A final report is due in June next year.
Coun Ian Ward, interim leader of Birmingham City Council, said: "As well as updating the Victorian infrastructure of the Council House, this provides a once-in-a-lifetime opportunity for Birmingham Museum & Art Gallery to be redeveloped as an international destination which reflects the city's stories to the world."
The works will allow Birmingham Museums Trust to progress with plans to submit a funding bid to the Heritage Lottery Fund in late 2018 for support of the redevelopment project, followed by a second bid in 2019.
Ellen McAdam, director of Birmingham Museums Trust, added: "This appointment is an important step towards creating a new Museum for Birmingham.
"We look forward to working with Birmingham City Council to deliver the project. We can now begin fundraising in earnest.
"The Birmingham Museums' team will be working hard to take the project to the next stage. We will continue to engage with local communities to showcase the city's world-class collection.
"We aim to re-imagine this great historic collection for the young, diverse Birmingham of the 21st century."