Possibly already permitted outbuildings that already have plumbing such as workshops, offices, etc might be able to be converted to an ADU at a cost that does not result in the cost being more than the value added.Building an ADU is a lot of work and can be a slow process.  

If I have a capital provider whom wants to be 100% passive and is ready to invest $100k with me (cash), and I have all the syndication structure and offering documents for this project... can’t I just find an accredited investor, present them the deal / get them on board, and go through them?

I'd be looking at multiple structures. we try to build below the average new build cost in our market in Columbus Ohio which is 515,000 last year and we target land 40-50k and urban core adjacent where we get higher price per square foot. we build for clients with margin around $190 a sq ft depending on multi or single. we can get that down in our triplex it's a little higher on our single family homes because of garages and limited economies of scale. hope that helps. idk Philly but if you show me the area and styles of homes I can give you some more insights. 

It sounds like REsimpli has a lot of value and combines a lot of features so I don’t need to pay for subscriptions to 10 different platforms (and invest a ton of time learning their systems only to discover a better option and start the process over again).

Their cost structures are significantly different from what new investors face today.Maybe I haven't yet reached the section that addresses different market conditions and interest rate environments, but I’d love to hear insights from those with more experience.

Add the financing challenges and that you existing structure likely will become rent controlled.  

I wonder how they are structuring these ? 

The Yale Law Journal article, "Zoned Out: How Zoning Law Undermines Family Law’s Functional Turn," highlights this issue, noting that while family law has evolved to recognize diverse family structures, zoning laws have lagged behind, potentially hindering innovative housing solutions like co-living.Challenges for Co-Living InvestorsFor real estate investors interested in co-living, these restrictive definitions can lead to:Legal Barriers: Difficulty obtaining permits or approvals for co-living spaces due to non-compliance with traditional family definitions in zoning codes.Operational Challenges: Potential fines or legal disputes arising from housing arrangements that don't conform to local zoning definitions of a household.Market Limitations: Reduced ability to meet the growing demand for affordable, shared housing solutions.Advocacy for ReformThe Bloomberg article, "Why Are Zoning Laws Defining What Constitutes a Family?"

Seller Financing or Creative Structures – If the seller is open to financing, you may be able to negotiate terms that reduce the need for a traditional down payment.

DIY tax software like TurboTax may not handle nominee interest, depreciation, or LLC structuring correctly, so working with a real estate CPA experienced in sub-to deals is recommended.