The two terms are often used interchangeably to mean the same thing. In this website, the two are used in a more particular and careful way in order to make an important distinction.
‘Inclusionary zoning’ is used only in reference to the particular set of inclusionary housing practices and policies seen in the US. Put another way, it might be described as “American-style” inclusionary housing. Although all of the programs there vary in many details, they all fall within the same and recognizable model. (That model is described elsewhere on this website.)
‘Inclusionary housing’ is used more generally in reference to a variety of practices and policies directed at creating mixed-income projects through the development regulations and approval process.
There are two notable and effective examples of inclusionary housing. One is the afore-mentioned inclusionary zoning as practised in the US. The other is the ‘planning gain’ approach used across England – which could be called “English-style” inclusionary housing .
In this country, three major cities – Montreal, Toronto and Vancouver – also have adopted inclusionary housing policies. These share many features, and might be the basis for an emerging “Canadian-style” inclusionary housing approach.
Here is the important distinction that must be made. It is inappropriate to call any of these Canadian programs as ‘inclusionary zoning’. They use a set of practices that are distinctly different than those in the US and, as a consequence, are more limited in the affordable housing that they produce.