The Appraisal Independence Requirements (AIR) were developed by Fannie Mae, the Federal Housing Finance Agency, Freddie Mac and key industry participants to replace the Home Valuation Code of Conduct. The appraisal independence rules in Reg Z make it unlawful, in extending credit or in providing any services for a consumer credit transaction secured by the principal dwelling of the consumer (i.e. homestead) to engage in any act or practice that violates appraisal independence.