I can't resist talking about my blanket mortgages!!!!
We bought our first home for $20K in 1985. 4 years later we wanted to buy vacant farm land. 20 acres for $30K. Farm Credit Services suggested we use a local Savings and Loan and get a blanket mortgage. Normally, they'd want 25% down on vacant land. So we'd need to come up with $7500 down payment for the land. However, the blanket mortgage covered the value of the land plus the value of the equity in our home in one mortgage. Since the house was paid off, the combined value of the house and the vacant land was $50K. We already owned $20K in equity on the $50K total value. That's 40% in equity, which is more than the required 25% down. So we were able to purchase the land with no money down. Seems shady, but it's perfectly legal. So we did it.
4 years later the land was paid off and we wanted to move to a larger house. The current house was worth $30K, and the one we wanted to buy was $65K. We took out another blanket mortgage on both houses. So $95K in total value, of which, we already owned $30K in equity, so a bit over 33% of the total value. Again, no money down to buy the 2nd house. Only stipulation was when we sold the 1st house, we had to give the S&L enough cash to bring up the equity in the 2nd house to at least 25%.
None of this applies to you. I just couldn't hold it in any more.