While Calgary's downtown vacancy rate has improved ever so slightly from its 25.7 per cent high in 2017, there are four buildings in the core with no office tenants whatsoever.

The most significant of the four is at 801 Seventh Avenue S.W. — formerly known as the Nexen building — which emptied out when Nexen moved all of its employees to The Bow building last year.

It offers prospective tenants approximately 600,000 square feet of office space.

"That's actually quite unusual in any office market to see an entire major office building empty," said Susan Thompson, research manager for Avison Young.

Fly through downtown to see exactly what buildings are empty in the video above.

"There's only four buildings out of the 170 that we track in downtown Calgary that are completely vacant."

She says the Nexen building is a different case because it was occupied by one tenant and the landlord now has to decide what to do with the space as it's unlikely to attract another single tenant.

The old Nexen tower in downtown Calgary has no office tenants. The 37-storey highrise was completed in 1982. (Google Street View)

Other empty spaces

The other vacant office buildings on the list are:

The old Chamber of Commerce building at 100 Sixth Ave. S.W.

The Lougheed building at 604 First St. S.W.

The old SNC-Lavalin building at 909 Fifth Ave. S.W.

The Lougheed, which still houses the Grand Theatre, is currently having its office spaces renovated by the landlord, and the old SNC Lavalin building, like the Nexen tower, still houses retail tenants at ground level.

Four other buildings downtown are sitting at over 75 per cent vacancy, while 35 buildings are fully occupied.

Changing rate

Calgary's overall vacancy rate in the downtown sits at 24.2 per cent, according to Avison Young's market report for the fourth quarter of 2019.

That's down from 25.7 per cent in 2017, and the commercial real estate company notes that absorption of office space has been positive for two years after three straight years of declines.

Top tier buildings have the lowest vacancy rates, according to the report.

"We tend to see a flight to quality in office buildings during a downturn because there are tenants that are still doing well and they may have similar or even better budgets than they did before the downturn started," said Thompson.

"So they can now consider either better quality buildings or better locations."