The University of Calgary's move to relocate its School of Architecture, Planning and Landscape into a 180,000 square-foot space in the former Nexen Building — an office tower that sat virtually vacant for about six years — has been lauded by many as a big step for this city's downtown revitalization.

But this city has made many efforts over the years to encourage building owners to fill their empty office spaces with housing, and bring life to the streets that seem to empty out once it's quitti…