In the Greater Toronto Area, the added cost of a long commute often outweighs the savings from cheaper housing in the suburbs surrounding the city, according to a new study from the Canada Mortgage and Housing Corporation.

Homeowners attracted by the affordability of a house with a plot of land in a bedroom city can save money by commuting by public transit, the study found, but then the trade-off is the cost of your time as transit commuting takes longer than driving.

"It's important that people are looking at the cost of commuting when they're considering the cost of carrying a home," said Andrew Scott, a senior analyst with CMHC.

"They also should be looking at commuting times ... It can cost more than $500 a month to commute. It's going to be a sizeable portion of your budget."

CMHC estimates of monthly commuting costs for a single car and driver from some of the cities surrounding Toronto. (CMHC)

Using 2016 census data from Statistics Canada and estimates of housing costs from the same year from the Toronto Real Estate Board, the study crunched the numbers on housing and commuting costs.

Commuting costs up to $800 a month

Commuting costs ranged from an average of under $200 a month in the city of Toronto, to more than $800 a month in Halton Hills to the northwest, Georgina to the north and Clarington to the east of the city. For the closer suburbs, such as Mississauga, Brampton, Vaughan, Richmond Hill, Markham and Pickering, the cost of commuting was estimated at between $200 and $399 a month.

That's the cost of if there's only one person commuting in every household. But the figure is likely higher if both partners commute, Scott said. The CMHC's estimates factor the cost of operating a vehicle, but not the cost of parking — another added expense

The CMHC study did not compare the cost of living in downtown Toronto to the cost of living and commuting from the nearby suburbs such as Scarborough and Etobicoke.

But it estimated that the cost of a commuting within Toronto was just $115 a month — reflecting the fact that many people bike, walk or use transit and have very low costs to get to work.

"One of the things that makes commuting costs lower in Toronto is that residents have ready access to rapid transit," Scott said.

Here's the trade-off between commuting costs and housing costs compared with the cost of housing and commuting in Toronto. (Statistics Canada/Toronto Real Estate Board/CMHC)

He said commuting by transit is generally cheaper for suburban commuters, as it is for city dwellers. But transit inevitably takes longer — and how much longer you are willing to spend commuting via transit depends on how you value your time, he said.

This is an argument in favour of more investment in transit to the GTA suburbs, Scott said, as it is clear people are moving outside the city in an effort to afford a home.

About 67 per cent of commuters who live in the 905 area come into the city by car. Even within the city limits, 49 per cent of commuters use a car, the study found.

The number of people making long commutes is rising, with a 16 percentage point increase in the number of people who commute for more than an hour each way from 2011 to 2016.

About 600,000 of Toronto's 2.6 million commuters drove or rode transit for about 45 minutes, but 377,000 said it took more than an hour to get to work.

The farther they moved from the city, the lower the cost of homes and the lower their mortgage borrowing costs.

Depends where you buy

While housing is more affordable in places such as Clarington, Oshawa and Pickering, there has been pressure on housing costs in these areas as more people decide that living in Toronto is not affordable and seek a home outside the city, Scott said.

The trade-off between the cost of the commuting and the cost of carrying a home depends on where you buy, but commuting has a cost in both time and money, Scott said.

"Everyone in the GTA is different, but we wanted to bring attention the housing cost versus commuting cost."

​ ​

In cities like Oakville, Aurora, Richmond Hill, Vaughan and Markham, the larger size of homes means the average house price is higher than in the city, even without factoring commuting costs.

"It's hard to say why people opt for the suburbs, but wanting a single detached home can be something central for a lot of people," he added.

Some people enjoy a suburban lifestyle or they may select where they live because of a school they want for their children, Scott said.