The city's proposal to dramatically expand the amount of land open for suburban development is drawing fire from both sides of the debate.

In a report released Friday, planning department staff recommended adding 1,650 hectares to the city's suburbs. The expansion is meant to accommodate an influx of approximately 400,000 new residents over the next quarter of a century.

"It's really quite a striking example of just completely wrongheaded policy," said Robb Barnes, executive director of Ecology Ottawa, an environmental advocacy group. "It amounts to a radical assault on a number of files that are really critical to progress on environmental issues in Ottawa."

Barnes said curbing urban sprawl is one of the main ways the city can tackle climate change. By building up, not out, and pairing that with investments in transit and sustainable development, Barnes said the city could reduce carbon emissions.

Ottawa's urban boundary (CBC)

Sheila Perry, president of the Federation of Citizens Associations of Ottawa, said there are economic reasons to "hold the line" on the urban boundary.

Perry said the city will have to build infrastructure in the form of transit, roads, sewers and pipes to support those new neighbourhoods.

"I don't believe the city can afford to do that," said Perry.

Intensification targets too high, home builders say

The organization that represents home builders, meanwhile, says the proposed boundary expansion might not go far enough.

The report recommends 51 per cent of all new housing growth be accomplished through intensifying existing neighbourhoods, with the rest taking place on undeveloped lands. By 2041, the intensification target increases to 60 per cent.

Jason Burggraaf, executive director of the Greater Ottawa Home Builders' Association, said his organization supports expanding the urban boundary but is concerned that intensification targets are too ambitious. (Francis Ferland/CBC News )

Jason Burggraaf, executive director of the Greater Ottawa Home Builders' Association, said those targets may not be realistic.

If we shortchange the land expansion ... we're really squeezing people on both sides. - Jason Burggraaf

"It's a level of intensification that's high and that hasn't been achieved before," he said. "There's little appreciation of about how much impact that's actually going to have in existing communities."

Burggraaf warned that anti-intensification movements have already popped up in neighbourhoods like Westboro and Hintonburg, both of which have grown significantly denser over the past decade.

"It's not what people actually want to see in their neighbourhoods," said Burggraaf. "If we shortchange the land expansion ... we're really squeezing people on both sides."

The city's planning and rural affairs committees will consider the boundary expansion proposal at a virtual meeting on May 11.