For a variance to be approved these five conditions must be met

(A) The variance will not be contrary to the public interest; (B) The spirit of the ordinance is observed; (C) Substantial justice is done; (D) The values of surrounding properties are not diminished; and (E) Literal enforcement of the provisions of the ordinance would result in an unnecessary hardship.

If you are opposing the variance you should refer to one (or more) of the conditions as not being met. See NH ZBA handbook for a discussion of these.