Affordable Housing Institute (AHI) published a report on Al Zaatari Refugee Camp in Mafraq Governate, Jordan. The camp has become the second largest refugee camp in the world and the fourth largest city in Jordan.  

Though considered to be a temporary settlement, Zaatari is one of the largest and fastest-growing cities in Jordan, housing more than 120,000 Syrian refugees on a 2-square-mile plot of desert and costing $500,000 a day to run. Instant cities like Zaatari are not acknowledged as such, even though they last an average of 17 years and currently house 45 million people worldwide.  

Online home for the report
http://www.affordablehousinginstitute.org/?page_id=839