The province will offer thousands of dollars in rebates for homeowners who opt for energy-efficient renovations, including windows and insulation, the Ontario government said Wednesday. The announcement was well-timed, happening on a day that the temperature dipped well below zero.

Minister of the Environment and Climate Change Chris Ballard and Parminder Sandhu, chair of the Green Ontario Fund, announced the new measures at the MaRS Discovery District Wednesday morning.

The rebates will be offered through the Green Ontario Fund, the non-profit provincial agency funded by money from the province's cap-and-trade program.

The new rebates are:

Up to $5,000 to replace windows that meet specific requirements.

Up to $7,200 off new insulation, and a $100 rebate for air sealing.

Up to $20,000 for Energy Star-certified ground source heat pumps, or up to $4,500 to repair existing heat pumps.

Up to $5,800 off Energy Star-certified air source heat pumps, or pumps that meet program requirements.

Homeowners and tenants could also be eligible for a $100 smart thermostat rebate.

In order to access the rebates, homeowners will have to work with a contractor that's been screened and qualified under the program and listed at GreenON.ca.

Ballard said the program "will make it easy and more affordable" for homeowners to make environmentally-friendly choices for their home improvements.

"If you've got a cold second floor or extension that just never warms up, then the Green Ontario Fund is here to help," Ballard told reporters.

"Our homes are under-insulated. The older your home, the more money is leaking out through heat, through cold. Money is leaking, along with greenhouse gas pollution."

The Green Ontario Fund is part of the province's Climate Change Action Plan, which aims to cut greenhouse gas emissions to 15 per cent below 1990 levels by 2020, to 37 per cent by 2030, and to 80 per cent by 2050.

In Ontario, buildings generate nearly a quarter of greenhouse gas pollution, Ballard said Wednesday.

Under the province's cap-and-trade program, businesses that exceed the province's cap on greenhouse gas emissions must either buy allowances from the market at auction, or from companies that have kept their emissions below the cap. To date, the province has held four auctions, which have generated more than $1.9 billion in proceeds, Ballard said.

The province is required to invest all of those funds into projects that prevent or reduce greenhouse gas pollution, he said.

In addition to the rebates, Ballard also announced the creation of GreenON Support, a phone line that homeowners can call to get advice on what projects and rebates might be best for their home.