Ontario's proposed growth plan for the Greater Golden Horseshoe (GGH) area is being hailed by some as the pathway to "a better quality of life for residents" but slammed by others who say it "means less housing choice and higher prices for home buyers."

The GGH includes the cities of Toronto and Hamilton. It extends south to Niagara, east to Waterloo, north to Orillia and east to Peterborough. The province says the area will grow by four million people during the next 25 years, to a population of 13.5 million, working in 6.3 million jobs.

The proposed growth plan incorporates changes to four existing land use plans that have been developed over the years. They include protection of the environmentally sensitive Oak Ridges Moraine and the Niagara Escarpment. It also includes the Greenbelt Plan, which was implemented in 2005 to halt urban sprawl and protect agricultural lands.

Some key elements of the proposal:

Increase densification targets in existing built-up areas to 60 per cent from 40 per cent

Increase densification in other areas (excluding natural heritage features such as wetlands and woodlands, rights of way for infrastructure and prime employment areas) to 80 residents and jobs per hectare from 50

Require zoning along transit corridors to provide adequate density to support transit

Add the lands within 21 major urban river valleys and seven coastal wetlands to the Greenbelt

Preserve farmland by setting "strict requirements for the expansion of urban areas and allowing more flexibility for agricultural use in the Greenbelt"

Require municipalities to integrate climate change policies into their official plans and to conduct climate change vulnerability risk assessments when planning or replacing infrastructure.

"Ontario recognizes the myriad problems created by sprawl, from residents stuck in cars for hours to rising carbon emissions to municipal debts due to the higher costs of servicing sprawl developments," says Tim Gray, executive director of the environmental advocacy group Environmental Defence. In an editorial published by the Toronto Star, Gray writes, "If implemented property, (this plan) will bring more efficient land use, more climate-friendly communities, a greater variety of housing options and better quality of life for residents."

Ontario's home builders have a different view.

"This announcement means that you're going to see more intensification, more condos, less choice and higher prices," says Brian Tuckey, president and CEO of the Building Industry and Land Development Association. "The residential construction industry will adapt, as it has in the past -- it's going to be the residents and new home buyers that are going to pay the price."

The builders note that housing prices in the Greater Toronto Area have seen huge increases in the last 10 years. The average price of a detached home in the GTA was $459,000 in 2006 and is more than $1 million today, while condo apartments have gone from an average of less than $300,000 in 2006 to $459,000 in 2016. The average new condo is also smaller than it was 10 years ago.

Gray says there is no evidence that the Greenbelt policies are responsible for the jump in housing prices. "Sprawl-hungry developers perpetrate the myth because they want to continue their outdated pattern of paving over some of the best farmland to build car-dependent, low-density housing," he wrote. "Toronto housing prices are primarily increasing because people want to live in urban areas with a mix of housing options that are served by public transit and have high walk-scores, jobs and green spaces."

The builders say they support the move to have density along transit lines, but that congestion is already a serious problem throughout the Toronto and Hamilton areas, "and more intensification will make it worse unless there are massive public investments in infrastructure. The current financing system disproportionately places the brunt of paying for these infrastructure projects on new home buyers."

They also say that increasing density in existing communities is a bad idea because these areas "do not have the necessary infrastructure in place (transit, schools, hospitals, roads) to support these density targets."

Ontario Home Builders Association president Joe Vaccaro says the organization supports adding river valleys and wetlands to the Greenbelt, but says, "We need to build new communities where residents have housing choice with access to green space, good public transit and jobs."

The government is looking for feedback on the proposals until Sept. 30, 2016. Comments can be posted online.