The City of Toronto is currently studying ways to increase housing options/supply and planning permissions in areas of the city that are designated as Neighbourhoods in the Official Plan.
These are areas that are sometimes referred to as the "Yellowbelt", because they are seeing very little intensification and, in a number of cases, actually losing population. (They're also colored yellow in Toronto's land use map.)
Ultimately, the goal is to encourage more "missing middle" type housing forms; housing that is denser than single-family homes but smaller in scale than say mid-rise housing like Junction House.
Here are a couple of interesting charts from the City. Based on Toronto's Official Plan, "Neighbourhoods" make up 35.4% of the city's land area.
