(Also, the developer is reasonably experienced + wealthy and has personally guaranteed some of the existing development projects - but wants to move away from that)I'm also planning to get some equity in the JV / the broader development company (much less equity than if I were to be a pure equity investor of course). because I do think this could scale to 300-400 homes / yearOf note: These homes are modular in nature - so are faster to build and margins are projected to be attractive.My questions for you all is:Have any of you lent to development assets with cross-collateral from cashflowing properties like this?

They do not return phone calls and we aren't even sure they exist.

That is for, if necessary for us to sell our existing home and move to the number one produced, which will be the first "model home".

Quote from @Robin Simon: Agreed - but a conflict of interest can certainly exist with all good actors involved - I don't think it's relevant.

This starts early on with preventing what could potentially go wrong by attracting an awesome tenant and looking at what vulnerabilites currently exist in your property.  

-How do you manage thermostat and temp difference between up/down stairs (assume basement will be a lot cooler)? 

This may also be a candidate for a subject-to type transaction where you take title to the house "subject-to" the existing financing. 

The existing loan I obtained 6 yrs ago was a DSCR loan with a one year ARM - no prepayment penalty, that is coming due in October.

This policy will provide additional coverage above what your existing policy covers.

In the process of BUYING a PURE Option to buy a SFH subject to an existing loan (at a lower fixed long term interest rate)Let say the OPTION "Strike price" to BUY the property IF or WHEN the OPTION is EXERCISED is $300K The seller wants $60K to sell us the OPTION.