I'm having a hard time finding any estimating tools for this kind of a project, adding a story and multiple BR/1 BA, and wondered if there were any tools, sites or recommendations any of you have for this kind of a project. 

As for the refi side, DSCRs are an excellent tool to utilize as they are based off the property, not you as the borrower, so no DTI hits / personal income verification required.

I will use comp tools to appraise property value without the ADU to determine cost added by ADU.  

Be sure to check out the free tools BP provides to help analyze deals you may have and also market insights.

Check county recordsUse online search tools like PropStream, Reonomy, PropertyShark, etc.Use local GIS mapping tools (ask your county)Search online directories for LLC or TrustTalk to neighborsHire a skip tracerSend a letter to the propertyThere are a lot of options.

We think a smartphone app-type, GPS-enabled time tracking tool for tasks and hours would be a good start.

I'm curious if there are any other marketing tools that have brought about success. 

@Itay Heled  larger properties are not something that is popular with the furnished finder searchers from what I have seen.

Great tool

What are the best resources / tools to get connected/educated on this type of asset?