So, the material I need will need to be sun, water, and scratch resistant but economical.

Everything else, including investing in a fund, requires a certain amount of "active", at a minimum doing enough research to decide if and how much to invest in the fund, monitoring the fund's performance, economic climate, future prospects and deciding if and when to sell.Some people consider investing in individual trust deeds /mortgages passive investing.  

I realize this is less of an investing question and more of a general economic question.

I would say it is worth it if the market is starving for economical housing.  

Look at the economic factors that drive this and see if its external fabrication.  

I have talked to the head of economic development of the city and he talked to me about the zoning codes and limitations of constructing a new building.

I wanted to quickly address the tax advantaged accounts being inaccessible until 59 1/2.

Due to recent declines in the energy sector and the resulting economic slowdown, Houston has begun to exhibit a softening in price growth.https://www.recenter.tamu.edu/articles/technical-report/Texas%20housing%20economy%20leading%20index%20construction

We looked at a property like this and the cost to bring all the units up to code even if we had gotten the property for land value would have not made economic sense.  

At the moment, I'm a year away from graduating with a BA in Economics from Columbia University.