They need to do all their due diligence including understanding the value that will be added by the ADU, the finance options available, the consequences of adding the ADU (rent control, property taxes, rental limitations, etc), etc.Good luck

There will always be some sense of resentment or issues that you leveraged control ect.

Dave mentioned control in the TIC but alot of times that is an illusion.

Quote from @Madelyn Felix: Are any property managers (with 20+ doors) controlling access for all of their properties under management remotely with smart locks-in one system? 

If you have only 2-3 rental properties, I would recommend taking full control of management at once rather than transitioning one at a time.

But most importantly, they do not need to be paid back.Funding Sources:Local Government/MunicipalitiesState GovernmentPrivate FoundationsFederal GovernmentFamily OfficesCorporationsWhen applying for a grant, ensure you have an understanding of the details such as eligibility, your project readiness, the purpose, funding amount, areas of funding, limitations and deadlines for the application.The prime candidates for a grant are 1) those developing a real estate project or physical space, 2) scaled non-profits and 3) certified non-minority owned businesses.Ensure you are able to provide the following documents before applying for the grant:Show site control through documentationA project description or business planConceptual drawings or renderings of the physical spaceProfessionally prepared budgets for the company and projectWhat does the grant application process look like?

If you do not know how to control money well, adding more to your bank account will only create new problems.

You would have to create an HOA to manage the common area and keep control of that or create a self-managing HOA for the four owners to manage together.

Could also rent it out, controlled by an agreed upon third party that distributes equal pay to each party, and hopefully could also pay the mortgage out of rental proceeds so neither of you are on the hook.

And, especially if your goal is to build a portfolio to live off of, bad deals (and even marginal deals), will keep you from achieving that goal much more than slowing down and waiting for better deals to surface.But beyond that, I also find I get most burnt out when I am invested in deals emotionally and with time.