Ontario is developing "substantive rent control reform," the housing minister said Thursday, as the provincial NDP push for tenants in newer units to have the same protections as all other renters.

Currently, annual rent increase caps only apply to residential buildings or units constructed before November 1991. This year the rent for those tenants could be increased by up to 1.5 per cent without the landlord applying to the Landlord and Tenant Board.

New Democrat Peter Tabuns plans to introduce a private member's bill Monday that would eliminate the exemption.

"A lot of renters are near their breaking point," he said. "Some have already gotten notices that their rent is being hiked and they're struggling to keep up and some are living with the worry that they could be next. I hear stories from young people who feel like they're one rent hike away from having to find a new home."

CIBC Economics said Wednesday that the average rent in the Greater Toronto Area has risen by nearly 12 per cent in 2016 to a record high of $2.77 per square foot.

"There is little doubt that the GTA's rental market has never been hotter," Benjamin Tal, deputy chief economist, wrote in the analysis.

Ontario Housing Minister Chris Ballard said it's "unacceptable" that many Ontarians are seeing dramatically increasing housing costs.

"My staff are already developing a plan to address unfair rises in rental costs by delivering substantive rent control reform in Ontario as part of an ongoing review of the Residential Tenancies Act," Ballard said in a statement.

"In the days ahead, we'll share more details about a transformative plan that will allow Ontarians, no matter their budget or community, to realize their dream of having an affordable place to call home."

Ken Hale with the Advocacy Centre for Tenants Ontario estimated there are about 150,000 rental households built after 1991 and therefore not subject to rent controls.

"Low and moderate income people who spend more than half of their income on rent are just a few steps away from homelessness," he said. "The law should not force people to live with this kind of uncertainty."

The post-November 1991 exemption dates back to a 1992 law -- from the NDP government and intended as temporary -- but has remained in various updated versions of tenancy legislation and become permanent.