Knox and Clayton Architects has proposed this extraordinary scheme, which will surround and sit above the B+-listed May Street Presbyterian Church in the middle of the city's central conservation area.
Conservation groups are to hold a strategy session to come up with a plan to oppose the commercial development, which was submitted for planning two weeks ago.
The Ulster Architectural Heritage Society is leading the charge - along with the Belfast Civic Trust and the Belfast Buildings Preservation Trust.
Researcher Rita Harkin said conservationists were left astonished when they first became aware of the plans to build over the top of the church, which was described by international architectural historian Charles Brett as 'really handsome'.
'We were silenced by the plans when we saw them. It was impossible to really say anything simply because we were amazed,' she told the AJ.
Knox and Clayton architect Philip Cullen described the first meeting with the local heritage lobby a little differently.
'Our meeting certainly wasn't as bad as we might have thought,' he said. 'We have had a positive result from most of the people we've consulted.
'We also have the support of the minister of the church; it is the centre of the Presbyterian mission to Belfast and we will provide them with new facilities,' he added.