Wolverhampton City Islamic Centre and Al Rahman Mosque has been operating as a mosque since June last year.
It is occupying the former Gala Casino building in Whitmore Street, which closed in 2011.
But now the council has granted formal permission for the change of use of the building.
Mosque manager Mekawy Morsy said he hoped locals would come to the mosque with any ideas they had for projects.
He said: "We would like the local people to come to us with their ideas.
"It doesn't matter where from – any faith or nationality – if they think they can use the centre we are ready to give back to the community.
"Wolverhampton is a mixture of all different nationalities and faiths.
"We are hoping to get people from all types of religion to come and so their prayer with us. It doesn't matter who you are or where you come from."
Mr Morsy also hopes to form a partnership with the University of Wolverhampton so that its Islamic students have a place to worship – an idea that the university has welcomed.
As part of the transformation of the site, prayers will be held five times a day, alongside the congressional Friday prayer, which all Muslims attend.
Arabic and Islamic studies will be taught and food will be provided for those fasting during Ramadan, while an Islamic marriage service will also be provided.
Mr Morsy said around 1,000 worshippers already used the mosque on Whitmore Street, Wolverhampton each week, including around 200 every Friday.
Leaders also want to paint the outside of the building and install signs bearing the mosque's name.
Already they have fitted new carpets and lights and painted the inside of the building.