Fannie Mae recognized that although a strong correlation exists between property values and GLA, there was little consistency as to how GLA was determined. This was evidenced recently in a survey of appraisers attending a class on ANSI standards and provided eleven different techniques they use to measure a one-and-a-half-story residence.

Per Fannie Mae, data also showed that when a second appraisal was submitted on the same property appraisers would report a difference of greater than 10% more than 20% of the time; and 40% of all submitted appraisals reported the square footage exactly as reported in public records.

Additionally, Fannie Mae has identified the following benefits of a universal standard:

• Creates alignment across multiple professions and sources
• Consumer protection and reduction in potential bias
• Transparent for the appraisal report reader.
• Professional and defensible for the appraiser.
• Consistent, repeatable unit of comparison for transactional data
• Higher confidence risk management and valuation modeling.
• Less re-training (ANSI is the most widely used GLA standard)
• In use by some states and county assessor offices
• Adopted by the National Association of Home Builders
• Ease of use: only 16 pages
• Existing continuation education classes are available.