I have some knowledge and experience of building houses. I did a lot of research and study but the idea didn't go anywhere. Unike in some countries land availability is really not an issue in Pakistan. Outside city boundaries one can have a plenty of land available for cheap.
I was actually interested in working on a housing project in Jamaica with my cousin. The idea was very simple:
The government guaranteed 80 percent loan for anyone who held a job and was registered in the tax network.
Prefabricated housing kits were brought in from China and the land was purchased by the developer.
I found out from China that one can build a one room house complete with electrical and plumbing for around $10000.something like this :
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The land preparation for services was the biggest cost but again it was doable and still make some profit.
I then found out that Jamaica is as corrupt as Pakistan and I pulled out. We even had the plans to build a resort again with a prefabricated structures but this time imported from Canada. This was our location:
we were going to build on the right side over the hill.
We are working with this company on our project here in Canada. we are building a resort and cottages but they are very expensive.
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So yes your idea is very good and it is perfectly doable. Only thing I am worried about is creating ugly , crowded and crime infested ghettos like in Latin America and NY.
but yes this can be done cheaply and efficiently with the high rise buildings.