It makes sense to me, and it's a good business decision as well. Consider, the average person buys a home, makes a down payment and then has to hope that their job and health holds out for 30 years. This lady finds the best location, razes a home and will erect another home. She'd be able to finance the cost of the construction through the land cost in all probability or even re-finance any costs she expends for construction based on the completed project. At completion, she'll have home that she can later sell if she desires, pay a mortgage she my take out based on the investment income from her personal wealth or pay it off entirely and enjoy the equity in her home.
So, it's amazing...or maybe not, that people take such a superficial view of her investment decision.