I don't know if this is lesswrong material, but I found it interesting. Cities of Tomorrow: Refugee Camps Require Longer-Term Thinking

“the average stay today in a camp is 17 years. That’s a generation.” These places need to be recognized as what they are: “cities of tomorrow,” not the temporary spaces we like to imagine. “In the Middle East, we were building camps: storage facilities for people. But the refugees were building a city,” Kleinschmidt said in an interview. Short-term thinking on camp infrastructure leads to perpetually poor conditions, all based on myopic optimism regarding the intended lifespan of these places.

Many refugees may never be able return home, and that reality needs to be realized and incorporated into solutions. Treating their situation as temporary or reversible puts people into a kind of existential limbo; inhabitants of these interstitial places can neither return to their normal routines nor move forward with their lives..

From City of Thorns:

The UN had spent a lot of time developing a new product: Interlocking Stabilized Soil Blocks (ISSBs), bricks made of mud, that could be used to build cheap houses in refugee camps. It had planned to build 15,000 such houses in Ifo 2 but only managed to construct 116 before the Kenyan government visited in December 2010 and ordered the building stopped. The houses looked too much like houses, better even than houses that Kenyans lived in, said the Department for Refugee Affairs, not the temporary structures and tents that refugees were supposed to inhabit.

From reddit:

Peru had an uprising in the 1980s in which the brutality of the insurgents, the Sendero Luminoso, caused mass migration from the Andes down to the coast. Lima's population grew from perhaps a million to its current 8.5 million in a decade. This occurred through settlements in pure desert, where people lived in shacks made of cardboard and reed matting. These were called "young villages", Pueblos Jóvenes.

Today, these are radically different. Los Olivos is now a lower-middle-class suburb, boasting one of the largest shopping malls in South America, gated neighborhoods, mammoth casinos and plastic surgery clinics. All now have schools, clinics, paved roads, electricity and water; and there is not a cardboard house in sight. (New arrivals can now buy prefab wooden houses to set up on more managed spaces, and the state runs in power and water.)

Zaatari refugee camp in Jordan, opened 4 years ago seems to be well on it's way to becomming a permanent city. It has businesses, permanent structures, and it's own economy.