I 100% understand that state, county within state, building type, age, depth of coverage, etc., etc., etc. is going to make every property unique, but it would be great to come up with a rough rule of thumb that will allow a conservative estimate.

For the lenders that do a 0 with decent credit you will need to put down 15% - 20% on a bridge loan and that's with 720+ credit.More than that though, you need to understand the capital requirements. 

If you look at those websites you can get an understanding of the process and costs involved. 

Be sure you understand the tax benefits and the errors that are often made that limit those tax benefits or come back to bite.

This is a two-way interview, so have a short list of questions to ask the mentor (What books do you recommend I read to gain a better understanding?

I am getting very close to understanding it.

The thing is to sell conventionally - potential buyers understandably would complain about the Ticky-Tacky stuff.  

The biggest problem with people doing driving for dollars is that they do not understand the concept of motivation.People often look for distressed properties.

If you put it on the city's radar you will need to bring it into compliance.I am not 100% sure I understand your overall question though...Are you wanting to put a rooftop deck on your roof and create a hatch in the enclosed porch to get to the roof top deck?

Understanding local regulations and zoning laws is crucial to avoid legal issues.