There are a lot of investment options.  

The cost to build will be significantly more than the amount of “value add” of an ADU putting you in a negative equity position.

Hello - After listening to the podcast, I've made a commitment to purchase a rental property by the end of Q2 this year (ideally by the end of Q1). I am interested in buying a long-term turnkey property in a nice area...

If you are interested in these options, reach out to me and my team can go deep with a couple of our lenders that offer these programs. 

Some will be ok in 2nd position and some will not and force you to refinance out the first - but those are options that are probably cheaper than credit cards 

However, I am unfamiliar with any lenders having traditional mortgage options for anything with a VIN number such as a trailer.

If you're already in a secure financial position, leveraging your equity could be a smart strategy.

Speak with a lender now to understand your options and start building a plan.

I see 3-5 as a fad.Fractional ownership - way to much overhead for these to be profitable. think "timeshare".STR in non traditional markets - running a STR is a business and real estate, boils down to location location location - who would want to go to a conference and stay in a STR vs. the hotel where the conference is at, most businesses pay for this I do not see why.Mixed use with green - this has been going on for years- it will continue but it is also more expensive to build - which means higher costs to use.Not trying to be debbie downer, I have seen these attempted to be done in the past and they really have not been successful.I do really like the BTR model though as I continue to see that as a very good option in the future. 

If so, I'd consider those options first as they fit in the infinite banking concept.