Compliance paths for IEQc8.1 have some key differences between v2.2 and v2009. In LEED-NC v2.2, Option 1: Calcualation allows you to show compliance with EQc8.1 by demonstrating over 75% of the regularly occupied areas have a glazing factor of at least 2%. These glazing factor calculations consider window, wall, ceiling and floor areas, glazing type and VLT values.
In LEED-NC v2009, the glazing factor calculations option has been removed. In v2009, however, the Option 2: Prescriptive method provides a new approach to demonstrate achievement of the credit that considers many of the same factors as the glazing factor calculations from v2.2.
Another significant difference between v2009 and v2.2 is that v2009 allows for a combination of compliance path options to achieve the credit, via Option 4.