Intrest (Halal ya Haram)

I think you mean to say "buy the house with cash money"..

Please consider the demand for housing will come down by 90% resulting in a total collapse of the industry thus making millions of people jobless/beggars...needing charity!!!

If you are rich enough to buy on cash please do so...if you try to implement cash system in a society you have to take care of a whole bunch of beggars putting extra burden on Islamic Zakat system>>