That said I strongly dislike when there's a conflation of "affordable housing" (lower-case, the general concept of providing for people on lower incomes) with specific schemes you have to qualify for (often "Afffordable Housing" upper-case) - in this case it seems to be deed restrictions on income that are required in exchange for floorspace bonuses and building code relaxations?
There's a big problem for me in the latter building inefficient bureaucratic systems and being able to be gamed (e.g. If I'm rich maybe I can still buy a lower income unit for my children or perhaps my wife or mother and then rent it out. I could lower my income for one year just to qualify etc.)