The Church of Scientology, which includes celebrities Tom Cruise and John Travolta among its followers, has submitted plans for a £6m "country-estate" headquarters in Birmingham.
The English neo-classical Grade Two listed building, located in the former premises of an insurance company, will provide a base to train members in "auditing" techniques aimed at recruitment across the Midlands.
The church bought the building seven years ago. An application has been lodged with Birmingham City Council to change the old mansion from office space into a place of religious education and worship.
The church plans to restore marble and oak panelling on the interior of the property which is set in mature grounds in Moseley.
The building's Hubbard Guidance Centre, named after the Scientology founder and science fiction author, L Ron Hubbard, will house a full wing devoted to "auditing"
Graeme Wilson, UK public affairs director said the building would be open to local people. The church currently has 118,000 members in the UK, 15,000 of whom are active participants.
Mr Wilson said: "The plans include a complete and sensitive restoration which will cost around £6 million and include skilled crafts to restore marble and oak panelling, as well as structural work to repair and bring back to good condition materials that have been worn or damaged over the years.
"We held two successful open day events last November and this gave us the opportunity to meet and talk to local people and listen to their thoughts. We were encouraged by the support we received on the attention to detail for the restoration proposals."
Birmingham City Council said it had not received any objections to the plan.