It’s still a worthy strategy to force cash flow that’s rare to find in SoCal, especially if you can reduce the cost of construction by doing a conversion/using an ADU grant or even buying a property with an existing ADU In general, even if the ADU valuation matches your cost including grants, they are usually not worth it in southern CA in single family zones. 

They realize the due on sale clause could get exercised and believe the risk is justified by the reduced rate.

Due to inflation and the drastic increases in material, labor, and supplies, that's naturally caused carriers to rethink limits/values on file. 

Using a 401(k) loan reduces your emergency liquidity, which could make the investment riskier if unexpected costs arise.

More and more investors are looking to assume low-interest loans rather than deal with reduced cashflow thanks to today's interest rates. 

This reduces exit options and affects the value. 10) Small number of small units is the most expensive residential development there is.

Framing your position as fair such as explaining the difficulty of finding renters during off-peak months - might help maintain a positive relationship and reduce risks of property damage.Prepare for What’s NextEven if the tenant moves out early, ensure you’re protected.

Focus on optimizing the current fourplexes (improving rents, reducing expenses).

And as investors we should know this, but always anticipate higher costs and longer waits.EXAMPLE Breakdown of Costs:Plan Purchase: $1,500Permitting Fees: $2,500-7,500Site Preparation (grading, utilities, foundation): $20,000–$30,000ADUs require separate utility connections for water, electricity, and sewer but you can tap into existing utilities at the primary houseIn Raleigh you CANNOT split lots fee simple, so setting up completely separate utilities would not allow you to section off the ADU as of nowYour ADU must be on a permanent foundation (no wheels, no ability to move the structure)Construction (labor and materials): $100,000–$150,000Low-grade: $150–$180/sq ft averageMid-grade: $180–$220/sq ft averageHigh-end: $220–$250/sq ft averageLandscaping/Finishing Touches: $5,000Total Estimated Cost: $125,000–$200,000You could easily spend $200k+ with super end high finishes, custom designs, complicated sitework, adding a second story or more sqft, etc.

Then ask them what your options are to reduce payments in the future.