Firefighters are concerned changes that allow Ontario builders to erect taller wood frame buildings will pose a greater safety risk, citing last year's fire at a Kingston, Ont. housing complex under construction as an example of what could happen.

The Ministry of Municipal Affairs and Housing made changes to the Ontario Building Code this week to raise the height of wood frame buildings from four storeys to six storeys high.

The ministry said the changes will make building a home more affordable and supports "more attractive, pedestrian-oriented buildings that enhance streetscapes."

New safety requirements for wood frame buildings include building stairwells with non-combustible materials and roofs that are combustion resistant, the ministry said in a statement Tuesday.

Kingston Fire 20131217

A crane operator was forced to sit on top of a crane while a fire raged below during the Kingston fire. The man was later rescued by a search and rescue helicopter from CFB Trenton. (Lars Hagberg/Canadian Press)

But Scott Marks with the International Association of Fire Fighters said the safety measures aren't enough.

Bigger buildings mean more fuel for fires

"The increase in the amount of wood in the structure increases the fuel load," said Marks. "When you start to tally up the wood in those buildings there is an incredible amount of potential fuel load for a fire and we've seen that in numerous wood structure buildings that have been burned while under construction, most recently in Kingston."

On Dec. 17 last year, a massive fire broke out at a housing complex under construction at 663 Princess Street in Kingston. So sudden was the onset and spread of the fire it forced a crane operator to climb to the top of the crane's boom and hang there until he could be rescued by a search and rescue helicopter.

The fire forced the evacuation of nearby buildings, and residents were not able to return home for months.

The builder and contractor in that incident are facing 22 charges from Ontario’s Ministry of Labour for failing to take proper precautions and impeding a Ministry investigation looking into the fire.

Marks said that fire raised questions about building code rules.

"All things being perfect, none of these building will start to burn. But our concern is if they do, how does leave the occupants and firefighters vulnerable? It just leaves a lot of concerns for us," he said.

Wood frame buildings may improve affordability

Scott Marks, International Association of Fire Fighters

Scott Marks with the IAFF said residents and firefighters are vulnerable should building fires spread quickly. (Julie Ireton/CBC)

The Canadian Wood Council has been pushing for the change in height requirement, but president Michael Giroux said his group wants to work with firefighters to keep the buildings safe.

"Firefighters should be concerned about any new innovation that's brought in to the codes. We seek to engage them in our discussions," said Giroux.

Giroux said the change will allow builders to lower costs, and potentially make buying or renting property more affordable for residents and businesses alike.