N.H. Rev. Stat. § 422-B:7
Upon receiving an application for a permit, the department shall make such investigation as may be necessary to process the application properly hereunder. If, upon such investigation, the department determines that a permit should not issue or that the height or location should be other than as applied for, the department shall thereupon notify the applicant in writing of its determination. Such notification may be served by delivering it personally to the applicant or by sending it by first class mail to the applicant at the address specified in the application. Such determination shall become final 20 days after notification thereof is served unless the applicant, within such 20-day period, requests in writing that a hearing be held before the department with reference to the application. All such hearings shall be open to the public. Any person interested may appear and be heard either in person or by counsel and may present such evidence and testimony as may be pertinent.
RSA 422-B:7
1959, 118:1. 1985, 402:6, I(c)(2).