Last month I wrote about energy efficient mortgages, a potentially transformative tool that rewards homebuyers with well-sealed houses, on the thinking that if your heating and cooling bills are low, you’ll have more money to make mortgage payments.

They’ve been available for a while, through conventional mortgage banks, the Federal Housing Administration, and the Veterans Administration. But few people know about them — mortgage lenders included — so they aren’t used very much.

Which makes it darn useful that has a new guide to energy efficient mortgages, along with a list of lenders in each state that are familiar enough with them. If you’re the home-buying type, it’s a good place to start learning about EEMs (after reading my article, of course).

Sen. Michael Bennet’s (D-Colo.) office says he’s looking into a bill that would make efficiency a consideration in all federally insured mortgages, which would be a huge freaking deal if it went through. In the meantime, pursuing an EEM on your own would help show consumers want resource-intelligent homes. You’d also save yourself a pile of money.

(There’s also talk about mainstreaming location efficient mortgages, which reward buyers who live in walkable, transit friendly neighborhoods, which tend to have lower transportation costs.)