Following a link on Frank’s blog, I learned about an innovative mortgage product from the Dutch Triodos Bank, the sustainable mortgage:
With the Triodos Mortgage you get a discount on the interest when your house becomes more sustainable. We offer the Triodos Energy Saving Loan for the renovation. With this loan you can finance up to 25,000 euros in sustainable adjustments to your home. The great thing is that the interest on this loan is only 50% of the interest on your mortgage.
This is an excellent idea.