The Energy Efficient Mortgage (EEM) allows a homebuyer to save future money on utility bills. This is done by financing the cost of adding energy-efficiency features to a new or existing home as part of an FHA-insured home purchase. The EEM can be used with both 203(b) and 203(k) loans. Basic guidelines for EEMs are as follows: The cost of improvements must be determined by a Home Energy Rating System or by an energy consultant. This cost must be less than the anticipated savings from the improvements. One- and two-unit new or existing homes are eligible; condos are not. The improvements financed may be 5% of property value or $4,000, whichever is greater. The total must fall within the FHA loan limit.