I’m not a constitutionalist, but I think there are always challenges when it comes to areas like health, housing or the environment. Notwithstanding the fact that housing normally falls under provincial jurisdiction, the funding and initiative for social housing programs came from the federal government from the 1970s until 1993. I don’t think anything has changed since then.
Of course, that would involve good faith on both sides, but, personally, I believe that rather than undertaking specific programs as it did back then, the federal government could set aside sums of money for the development of social housing before negotiating with the provinces. It could ask them if they want their share of this money for development. If they said yes, that money would be earmarked for social housing, and nothing else. The same could be true for many other areas as well.