reporter: organizazations le nhlanhla ndlovu's house-building together.. ndlovu could use the plentifulr building rubble for his environmentally-friendly bricks. now, the two are working on ways to crush the waste and transport it to the construction sites. they hope to get started soon. nondumiso: so we are working out how we can actually collaborate and use the rubble as raw material for making bricks with the rubble. and ththen it can be actuauallye profitable on bumbadotmobi's side and actually help hire more people, because then we would need people who are going to make bricks and people who are going to separate the waste and crush the waste as well. reporter: more than ththree million publicly-subsidized homes have been built in south africa in the past 25 years. even so, the government has failed to meet thehe need for w housing. nhlanhla ndlovu says that many who came to johannesburg hoping for a better life are now living in worse housing than before. they're exactly the people he wants to help, and not just by building homes for them. he has ma