After I blew it out and raised it to allow condensation to drip freely the problem remained. 

Will the banks allow that?

Most 401k administrators will allow you to borrow up to 50% of the account value or (not to exceed $50K).  

Hi guysI'm new to real estate investing and I was considering applying the 50% rule to my deal analysis prior to asking my real estate agents for actuals.I'm assuming this will help build credibility with them and allow for more concrete inquiries rather than constantly asking them for information on deals that may never get done.What are you guys thoughts?

The rent on the other side of the duplex covers expenses and will allow us to live almost rent and mortgage free.

Since you allow yourself 30-45 days to find a buyer if you cant find a buyer within that timeframe, you can walk away from the deal.

That could be one reason why the lots were never built on.Also, if it's a high-end subdivision, it's quite possible that the covenants won't allow you to build what is generally available with modular home designs. 

I would be tempted to tell you to do what is average for that neighberhood but your idea might just work if you do not misfigure your time allowed for each project.  

If the city allows you to purchase the homes, they would certainly be very cheap.

And @Richard Capers Jr 's suggestion of checking out whether or not a duplex is allowed and do-able is another good one.