Proof of the fact of a shortage of single-family detached housing is that the price has increased twice as fast a high-density housing i.e. condos.  
The use of "changing the mix of housing" is another example of his BS.  That is irrelevant, what is relevant is the new housing that is available to new buyers, and it is not single-detached housing.  It is condos and that is not what people want.  I could go on and on about how he is distorting the facts.
Victor is defending his political position and hiding the facts with a lot of mumble jumble.  He needs to be removed from his position in the government.