Cork City Council is blocking attempts by developer BAM to make further changes to their original plans for the events centre site.
The developers want to reduce the planned brewery interpretation centre in the heart of the Beamish & Crawford development and to drop plans for a seven-screen cinema.
The building company lodged plans in November seeking permission to modify the original planning application.
The central site was to include a brewing experience interpretive centre that would detail the history of brewing on the site along with other archaeological discoveries.
However, Bam's revised plans have reduced these elements and instead want to use the space for offices and educational uses.
Planners in City Hall have now written to BAM outlining concerns they have over the reduction in space for an interpretive centre.
They said such a centre would "serve as a cultural/interpretive space dedicated to the findings from city centre archaeological discoveries and the former use-history of this and other sites in the immediate vicinity."
"The reduction in such space and the dispersed nature of the revised proposal diminishes this potential and the scope to develop a significant cultural/tourist offering (reflecting the importance and history of the site)."
Bam has now been instructed to prepare a clear strategy for the use and integration of the former brewery's cultural space.
Planners are also seeking clear proposals for the preservation of a fireplace in the Beamish & Crawford boardroom that dates to 1662 and and a date stone on the side of the building from 1792.
Construction is already underway on student apartments on the northern end of the Beamish site, though uncertainty surrounds the remainder of the project as the Government mulls over an extra €10m investment on top of the €20m already sanctioned for the Events Centre at the southern end.