The cost of affordable housing: Does it pencil out?

Summary

"There is not enough affordable housing in the United States. For every 100 extremely low income households, there are only 29 adequate, affordable, and available rental units. That means two parents who both work minimum-wage jobs might wait years to find a safe, affordable place to live with their two kids. With such high demand, why aren’t developers racing to build affordable apartments? It turns out building affordable housing is not particularly affordable. In fact, there is a huge gap between what these buildings cost to construct and maintain and the rents most people can pay. Without the help of too-scarce government subsidies for creating, preserving, and operating affordable apartments, building these homes is often impossible. This tool helps explain why."
Text from: http://apps.urban.org/features/cost-of-affordable-housing/