The Financial Post reports in its Friday, Sept. 4, edition that the number of empty offices in Alberta is projected to spike, as Colliers International predicts an "ill-timed" building boom should push up vacancy rates in Calgary and Edmonton. The Post's Geoffrey Morgan writes that Colliers economist Andrew Nelson says, "The fall in oil prices has had a negative impact on the energy-reliant markets (in Western Canada)," which has contributed to rising vacancy rates and falling rental prices in Alberta's two largest cities. Vacancy rates jumped over the course of the second quarter. In Calgary's case, Colliers reported the downtown vacancy rate rose to 13 per cent from 10 per cent, while Edmonton's vacancy rate increased to 11.2 per cent from 10.6 per cent. A glut of new buildings under construction in both cities could push those numbers up even higher. Calgary Chamber of Commerce director of policy and research Justin Smith says escalating costs made it difficult for some companies to stay in downtown Calgary. He notes that even large companies like Imperial Oil and Canadian Pacific Railway moved their head offices to the suburbs. The uptick in vacancy rates could make rentals cheaper for smaller companies.