To quote the web site:
A 39,500sf renovation to consolidate and modernize the 3 buildings that make up 855 Granville Street . . . The renovation taking place on 855 Granville will further consolidate and modernize the three buildings with a brilliant new articulated glazed look while respecting the existing heritage building facades. . . . Be a part of the trend and join the newly emerging technology demographic with major tech companies opening offices along Granville Street.
These plans look like a reworking of an earlier proposal by Studio One Architecture. You’ll need to click on Current Projects / Heritage Conversion. There seems to be no direct link.