Hi Molly,
While I’m not a lender or an attorney, I have seen similar situations as you describe here and have 20+ years experience analyzing leasehold interests.
Unfortunately, your options for financing are limited because you don’t own the land under your improvements. Unless the tract has been previously subdivided, you probably can’t sell your portion of the property and anyone who wanted to buy it couldnt except for cash, and assuming your ground lease, for which they’d expect a huge price discount.
There may be private lenders out there who loan on leasehold interests, but I doubt you’ll like the terms or they’re going to base the loan amount on anything near the fee simple interest or cost of the improvements, without a lien on all the land.
At this point, you probably can’t refinance your properties without your parents subordinating their interest in your leased land and your parents signing on the loan, which would likely be secured by the entire property. If that works, great.
If in your present situation, I would hold off on any other construction on this land until I could visit with my parents and an attorney to try and change the lease agreement into something that would maximize the value to YOU of any improvements you place on the land, now or in the future.
If it was just so you had a place to build your own house, the lease might be ok, but there are a number of better options than this lease for an investment property.
An easier option mat be to convey your parents RE interest into an LLC for the entire property and divide the ownership based on the value each party has at this time. They can leave their part of the LLC interest to you in their will. Check with a CPA of course, but I don't believe an LLC conversion would trigger a tax issue. It's also possible they could subdivide the tract and sell or gift you the underlying land.
You’ve done a great job of developing income producing real estate and it sounds like you’re on your way to more success. Being a pro investor means never skimping on expert CPA and Attorney advice as to how to maintain the long term value and appreciation of your RE investments. If their advice doesn’t sound right, pay for a 2nd opinion.
BTW I grew up hearing folks say a 99 year lease is the same as pure ownership, but this is simply not true as it is much more difficult to finance and sell in the open market.
Marketability is everything when you’re talking about real estate values.
Good luck!