The historic Red Home building was originally meant to be kept as part of Foster and Partners' £400 million redevelopment of the Royal Infirmary of Edinburgh site, but is now in line for demolition in a brazen backtrack.
Heritage body Edinburgh World Heritage (EWH) has slammed the proposals, claiming the former nurses' accommodation should remain intact to ensure a balance is kept between the existing eight listed buildings and the 19 new blocks.
EWH director Zoe Clark said: '[We believe] that the demolition of the Red Home has not been properly justified by the developer.
'The Red Home is a very distinctive building and an important reminder of the area's heritage. We do not believe that the condition of the building or adapting it to other uses has been fully explored.
'Quartermile could still be an exemplar of reuse and complementary new design, but it risks becoming a high-density luxury housing scheme that pays lip service to conservation and world-heritage values.'