Building "affordable housing" doesn't pay.

In fact, it is a money sink and you can't get financing for such a project.

Buy two bedroom house, add 3rd bedroom and a bath, and now you have a 3br house, which sells for more. Fixing the two bedroom up to code, and reselling doesn't make you enough to pay for the repairs you did.

This is all caused by banksters and their being able to print money to create mortgages.
And the amount you can mortgage, goes mostly into the ground. Its expensive ground and a cheap structure. And you can't build a cheap house on expensive ground.