Heritage preservation has to balance the pure preservation goal with the context and continued function of the structure. We preserve historic buildings that did not have plumbing for their first 100 years - but we don't preserve the outhouse, nor do we insist people use the outhouse just because that's a heritage attribute of the building.
The mistake made with Union's trainshed preservation was to put a green roof on top. (one progressive agenda, quite a good idea in other contexts, too far). Had the roof been retained with translucent panels, a better compromise could have been reached.
I sit on one of the city's Heritage Preservation panels, so I'm not going to speak out against preservation...... but forcing the travelling public into a dark, dreary structure just because that's what travellers traditionally experienced is not a wise strategy either for preservation or for urban development.
My suggestion would be - nix the green roof - or at least reduce its area - change the roofing material, but keep the trainshed structure.
- Paul