I understand a duplex may have an Accessory Dwelling Unit (ADU).The objective is to get a permit to change the windows, put up siding, and add a fence.  

I tried to search online to renew but my name is not under this previous certificate. 2.

Looking online is better than nothing, but selected pictures never tell the full story. 

Now I still feel interconnection is hard to estimate as investor even some of these information are available online and this is the biggest risk I am taking here.

Start by identifying your goal objectives. 

From my online research the prices are too high and pretty much a not so ethical way off doing business.

.#6) Here's an excellent, objective resource that may help further: https://www.investopedia.com/articles/personal-finance/06151...We hope this helps!

Fix everything you plan to, clean it, have it professionally photographed and listed with a realtor to make sure you get fully vetted tenants and the most options.If you were a renter in today's market and walked into a new listing with a nice front photo online and it was under renovation, would you pay market value?

Are you interested in collecting payments online with the reporting included or just rent reporting without online payment processing? 

Check out other online guides available here: https://www.biggerpockets.com/guides3.