N.H. Rev. Stat. § 422-B:4
No permit shall be issued to erect, add to or replace any structure which will extend more than 1,000 feet above the highest point of land within a one-mile radius from the location of the structure, except as hereinafter provided, nor shall any person erect, add to or replace any structure for which a permit is required that exceeds the height allowed by the permit. The department may issue a permit to erect or add to a structure which will extend to a height of more than 1,000 feet above the highest point of land within a one-mile radius from the location of the structure proposed to be erected or added to if such proposed structure will not be higher than 50 feet above the height of the highest structure in existence on May 25, 1959, which is within a distance of one mile from the location of the structure proposed to be erected or added to. In any instance where an application is pending before the federal government or some agency thereof for the erection of an electronic or other structure, the department shall not issue a permit for such structure until after the federal government or the agency thereof before which such application is pending has taken final action on the application.
RSA 422-B:4
1959, 118:1. 1985, 402:6, I(c)(2).