They can pay the mortgage, but what about the heating bill?

Should the government require that the cost of heating, cooling and lighting a home be be disclosed in all real estate transactions — and used as part of the equation for determining whether buyers can qualify for a mortgage?

That’s one possible strategy for promoting “net-zero”-energy homes put forward in a new report by the National Institute of Standards and Technology. The report recommends “incorporating energy in the appraisal process, and the valuation of principal, interest, taxes and insurance (PITI), so that it incorporates energy cost considerations to become the valuation of principal, interest, taxes, insurance, and energy cost considerations (PITIE).”

Lenders often use PITI to ensure that borrowers have enough reserves to pay their mortgage for a few months if they lose their jobs.

The Appraisal Institute, the largest group representing real estate appraisers, already offers a “Residential Green and Energy Efficient Addendum,” aimed at helping homeowners get a fair return on investments they make in energy-saving home features.

More than 200 of the nation’s 860 multiple listing services have added “green fields” to their data input forms. The National Association of Realtors, builders, appraisers and environmental groups are encouraging MLSs to add green fields to listing forms through a campaign called “Green the MLS.” Source: nist.gov.