Tier 1 - Ground floor additions 399 sq. ft. or less.
Tier 2 - Ground floor additions up to 899 sq. ft., upper floor additions up to 399 sq. ft., or a combination of upper and lower floor additions up to 899 sq. ft.
Tier 3 - Ground floor additions greater than 899 sq. ft. and/or upper floor additions greater than 399 sq. ft.
