Required interval for hearings on applications and appeals after denial. Whenever the Board, after hearing all the evidence presented upon an application or appeal, under the provisions of this chapter, denies the same, the Board of Appeals shall refuse to hold further hearings on the said or substantially similar application or appeal by the same applicant, his or her successor or assign for a period of one year, except and unless the Board of Appeals shall find and determine from the information supplied by the request for a rehearing that changed conditions have occurred relating to the promotion of the public health, safety, convenience, comfort, prosperity and general welfare and that a reconsideration is justified. Such rehearing shall be allowable only upon a motion initiated by a member of the Board of Appeals and adopted by the unanimous vote of the members present but not less than a majority of all members.