A report detailing Calgary's bustling downtown office market is suggesting a potential over-abundance of space could result in increased vacancy.

With as much as 7.5 million sq. ft. of space set to come to the downtown core over the next four to five years, a report from Cresa calls the potential impact of the current level of development "significant", adding to the possibility of increased vacancy in the area.

Calgary's commercial market continues to rise to new heights with second quarter investment in the sector totaling nearly $1 billion.

According to a report from RealNet Canada Inc., investment in the sector climbed by 28 per cent in the second quarter of 2013 for a total of $925.52 million.

Space in Calgary's once constricted downtown office market could soon be a little easier to come by.

While ranked as the tightest market in Canada in a report from Avison Young, the vacancy rate in the downtown core could escalate alongside new developments set to enter the market.

Brookfield Office Properties Inc. has announced Cenovus Energy Inc. will be the anchor tenant for their new 56-storey, 247-metro tower in downtown Calgary.

Expected to create 1,300 construction jobs and 7.5 million construction man-hours in Calgary, the entire project calls for an additional office tower totaling approximately one million square feet, a 60-foot-high transparent glass pavilion, restaurants, retail shops and amenities at street level, and underground parking accommodating 1,100 parking stalls.