Each member of the state board of registration for professional engineers and surveyors shall be a citizen of the United States and a resident of this state, shall have been engaged in the practice of the profession of engineering for engineers or the profession of surveying for surveyors for at least twelve years, and shall have been in responsible charge of important engineering or surveying work for at least five years. Responsible charge of engineering or surveying teaching shall be construed as responsible charge of important engineering or surveying work.