New York Times

Trump wants to deport or otherwise push "illegal" immigrants into internment/concentration camps. This is a cohort of individuals that typically don't buy homes anyway, and it will increase costs on building because the same cohort is frequently engaged in home building projects already. It will do nothing to bring home prices down for anyone aside from billionaires who will snap up the homes that are forcibly vacated by the few immigrants that managed to buy homes somehow.

So, it'd be a net negative for all parties involved. It's a terrible plan, conceived by terrible people.