On September 29, 2011, the Appraisal Institute issued a Green/Energy Efficiency Addendum to its standard Fannie Mae Form 1004. The form has sections for including energy efficient appliances, water savings, energy audit results, energy bills and more. It can be downloaded here.
According to the release by the Appraisal Institute, Form 1004 is "the appraisal industry’s most widely used form for mortgage lending purposes. Used by Fannie Mae, Freddie Mac and the Federal Housing Administration, Form 1004 is completed by appraisers to uphold safe and sound lending. Currently, the contributory value of a home’s green features is rarely part of the equation.
This kind of standard form for valuing green features gives specific guidance for appraisers on what to look for and include in the audit. How the information translates into valuation remains to be seen, but it is an excellent step in the right direction.