If you have millions of dollars to invest, amassing multiple real estate properties is not a problem. If you aren't named Buffett or Gates, however, it's not usually an option.

Fortunately, the average investor has another option. Real estate investment trusts (REITs) are companies that own income-generating properties in a pool, allowing interested investors to add real estate to their portfolio without breaking the bank.

Over-supply, fewer newcomers behind increasing vacancy rates

Vacancy rates in Calgary have spiked so far this year and are expected to rise for the foreseeable future, say industry insiders.

And with few signs of significant changes in the economy on the horizon, renters will enjoy plenty of choice and price flexibility, while landlords will need to get aggressive.

"Vacancy started rising pretty rapidly after the spring of last year and it's still been rising," said Gerry Baxter, executive director of the Calgary Residential Rental Association, which has about 850 members, representing between 65,000 and 70,000 rental units. There are more than 700 landlords in the association.