What about Energy Efficiency Mortgages in the US? Here in Colorado we have a non-profit organization which inspects homes and gives them an energy rating. Based on the rating of the home and/or the expected benefits of energy efficient upgrades, part of the loan can be financed at 100% (I believe). There's more here:
http://www.efanniemae.com/hcd/single_family/mortgage_products/eem.html
and here:
http://www.e-star.com/homeowners/index.html
I make my living designing "green" buildings. Our clients rarely have problems with mortgage approval. We stick to local banks that know local conditions. We can show a positive cash balance for our buildings versus business-as-usual. What we do is simple enough to be understood by an average 11 year old. So I'm not sure that the premise holds water.
In the early 80's, I was able to convince several small banks in my area to offer a lower mortgage rate to energy-efficient homes, because someone with lower fuel bills is more likely to meet the mortgage payments - they're lower risk. That was great, until the banks were swallowed by conglomerates. But the idea is returning now - good thing.