TORONTO -- The Ontario government is dismissing suggestions that the province's anti-sprawl policies are contributing to housing supply shortage and soaring home prices in the Greater Toronto and Hamilton Area.

Developers argue that easing restrictions on construction of detached homes and townhouses on "greenfield" land -- areas set aside by municipalities for development as part of Ontario's growth plan a decade ago -- could help boost supply.

The province is expected to release its updated growth plan this spring after years of consultations, but preliminary recommendations suggest it will be more restrictive of low-rise homes, with higher intensification and density targets aimed at limiting urban sprawl.

The Liberals have promised to bring forward a package of housing affordability measures, with at least some of them to be included in the spring budget.

The Building Industry and Land Development Association (BILD) would like the province to make changes to its growth plan that will allow developers to build more low-rise detached homes and townhouses on unbuilt land in the GTHA.

BILD and other industry groups note they aren't proposing venturing into the Greenbelt -- an 800,000-hectare area of government-protected swaths of farmland, green space and wetlands around the GTHA. Instead they're suggesting targeting the "greenfield" lands on the outskirts of the region's cities.

The association's president and CEO Bryan Tuckey says the restrictive growth plan policy that's been in place for the last decade -- known as Places to Grow -- has contributed to the housing shortage and soaring home prices.

In 2002, there were 53,660 homes sold in the Greater Toronto Area (GTA), 72 per cent of which were low-rise, according to BILD. Last year, there were 47,161 homes sold in the GTA -- 38 per cent were low-rise and 62 per cent were condo apartments.

Municipal Affairs Minister Bill Mauro wouldn't comment on the updated growth plan -- but he disagreed with the BILD's premise that the growth plan is tied the hot housing market.

"That line of thinking is looking to create a link between housing pricing and the growth plans and Greenbelt policies," he said last week. "We don't think that's the situation."

Mauro said the government doesn't see the availability of land as an issue because there is enough serviced land -- connected to municipal water and wastewater systems -- to accommodate three to four years' worth of development.

The Neptis Foundation, a charitable foundation that does urban planning research, released a report last month that found there is a significant amount "unbuilt" land in the GTHA still available for development.

It calculated there is over 45,000 hectares of "greenfield" land that remains unbuilt.

Most of it is located on the outskirts of built-up areas, for instance in Brampton, Vaughan, and East Gwillimbury -- but none in Toronto or Mississauga, said executive director Marcy Burchfield.

The land is enough to accommodate housing and job growth to 2031, if not beyond, she said.

To speed up development of that land, the provincial government could "play a more active role," in making sure that municipal zoning aligns with the Ontario's growth plan and the development approval process works swiftly, Burchfield said.

The development industry is also calling for the government to find ways to expedite the planning approval and appeals process, to allow for faster building.

Mauro acknowledged that, in some cases, that process might be taking too long.

"We're still doing a deeper dive on that," he said.

The average selling price for all properties in the Greater Toronto Area was $916,567 last month -- a 33.2-per-cent jump from $688,011 in March 2016.