In several Toronto schools the classrooms are too hot in the summer, too cold in the winter, and some rely on water boilers so old that when they break down, customized parts are needed to fix them.

The conditions are bad enough that one former trustee says the country's largest school board faces a tough choice: pour millions into repairing the buildings, seek more government funding to expand existing schools with portable facilities, or focus on building brand new schools.

The average TDSB school is now over 60 years old, and some of the city's schools have been around for more than a century. The board says with around 600 buildings to manage, it's doing its best to chip away at the estimated $3.5 billion in repair backlog, but the province will only kick in $292 million in renewal funding in the 2019-20 school year.

According to this TDSB data, there are 14 schools within the board that would cost more to repair than to rebuild. The list of schools include:

Etobicoke Year Round Alternative Centre Oakdale Park Middle School Amesbury Middle School Winona Drive Senior Public School Charles G. Fraser Junior School Ryerson Community School Montrose Junior Public School Winchester Junior and Senior Public School Blythwood Junior Public School Eastdale Collegiate Institute Glen Ames Senior Public School Secord Public School Vradenburg Junior Public School Timberbank Junior Public School

Krista Wylie launched the Fix Our Schools Campaign five years ago to advocate for more funding city-wide.

She says after speaking with other parents, she realized school repairs were an issue province-wide, not just in Toronto.

"How sad it is that as a collective we've allowed buildings where children spend their days to get to that point," Wylie said. "It makes me very sad and worried."

Krista Wylie, founder of the Fix Our Schools campaign, says she often hears stories from students of leaking roofs and cold classrooms. (Talia Ricci/CBC )

Wylie says while she believes the boards are doing their best to ensure safety, it remains a concern for the group.

Meanwhile Ken Lister — a former TDSB trustee — says in his four years on the board, repairs were a huge priority. He says he doesn't understand why the investment isn't being made to build brand new schools instead of slowly managing the repairs.

"When you look at that data and you see it'll cost more to do those repairs than simply tear the building down and build a new state-of-the-art school, that's when you really have to scratch your head," he said.

Ken Lister, a former TDSB trustee, says he continues to be passionate about the state of school repairs as a parent. (Talia Ricci/CBC)

Lister points out how widespread the repairs are across the board with schools in the downtown core, Scarborough, Etobicoke and North York.

"There's a number of repairs that need to be done and the state of repairs has been getting progressively worse each year," he said.

"That was deeply concerning to me when I was a trustee and now as a parent."

It's more complex than just rebuilding a school: TDSB

Ryan Bird, spokesperson for the Toronto District School Board, says health and safety is the first priority when it comes to determining what gets repaired.

"When there are larger issues, we try to address them as best we can, but if they aren't an urgent issue we add them to the list for down the road should we get money," he said.

Bird says urgent matters include leaking roofs and broken heating, "so that people aren't wearing jackets and feeling cold," although he admitted "sometimes that still tends to happen."

Ryan Bird, spokesperson for TDSB, says the board is investing the millions it does receive as best it can where the money is needed now. (Talia Ricci/CBC)

The 14 schools highlighted have a facility condition index (FCI) number of more than 100 per cent, which is calculated by taking the total cost of repairs and dividing it by the value of replacing the entire building. The Ministry of Education hires independent, third-party facility inspectors to gather the information.

But Bird says the situation is a lot more complex than these numbers show.

"There are so many aspects to that, like where do the students go in the meantime while that school takes years to build," he said.

"There are multiple schools that could potentially be replaced by a new school, but do we have the student population there anymore?"

Bird adds that in some cases, the board has managed to extend the life of high priced repairs like boilers.

"So yes, it needs replacement and it would be taken into account when you calculate that FCI number, but it's working so right now we're not replacing it," he said.

Ministry of Education responds

Ontario Education Minister Stephen Lecce launched a program last year that will invest more than $500 million into new schools and renovations.

The ministry says that's in addition to the $1.4 billion allotted to repair and renew Ontario's schools for the 2019-20 school year.

Lecce now says the ministry is currently reviewing proposals submitted by school boards.

"I accept that the quality of our schools and the facilities that house our kids need to be better," he told CBC Toronto in a scrum at Queen's Park Thursday.

Government moves forward with school repair funding; asks boards to submit funding requests

"We're going to continue to make capital investments a priority for urban and rural schools."

Wylie says Fix Our Schools is pushing for an additional $1.6 billion from the province, in addition to what Ontario schools are currently receiving.

"As adults, we often give lip service to the fact that children are our future, and that their education is of paramount importance," she said.

"Yet hundreds of thousands of students spend time in buildings that say otherwise to them."