It's not a matter of competence alone...
It's NY Law
http://www.dos.state.ny.us/lcns/lawbooks/re-appraisers.html
RULES AND REGULATIONS
TITLE 19 NYCRR
BOARD OF REAL ESTATE APPRAISAL
PART 1101
SCOPE OF PRACTICE This information is not the official version of the
Official Compilation of Codes, Rules and Regulations of the State of New York (NYCRR). No representation is made as to its accuracy, nor may it be read into evidence in New York State courts. To ensure accuracy and for evidentiary purposes, reference should be made to the official NYCRR. The official NYCRR is published by West, 610 Opperman Drive, Eagan, MN 55123, 1-800-344-5009.
§1101.1 Scope of practice for certified general real estate appraiser
A certified general real estate appraiser may appraise all types of real property.
§1101.2 Scope of practice for certified residential real estate appraiser
(a) The scope of practice for a certified residential real estate appraiser is limited to:
- (1) the appraisal of 1-4 family residential units without regard to value or complexity; and
(2) the appraisal of vacant or unimproved land that is to be utilized for a 1-4 family residential unit without regard to value or complexity, or vacant or unimproved land for which the highest and best use is a 1-4 family residential unit without regard to value or complexity.
(b) A certified residential real estate appraiser shall not appraise a residential subdivision, except that a certified residential real estate appraiser may appraise individual properties within a subdivision.
§1101.3 Scope of practice for a licensed residential real estate appraiser
(a) The scope of practice for a licensed residential real estate appraiser is limited to the appraisal of noncomplex 1-4 family residential units having a transaction value of less than $1,000,000 and complex 1-4 family residential units having a transaction value of less than $250,000.
(b) The scope of practice for a licensed residential real estate appraiser includes the appraisal of vacant or unimproved land that is to be utilized for a 1-4 family residential unit or vacant or unimproved land for which the highest and best use is a 1-4 family residential unit. In either case, the scope of practice is limited to the appraisal of vacant or unimproved land having a transaction value of less than $1,000,000.