In the conduct of hearings related to permanent variances, the board and its representatives are not bound by common law or statutory rules of evidence or by technical or formal rules of procedure but shall conduct the hearings in accordance with Article 8 (commencing with Section 11435.05) of Chapter 4.5 of Part 1 of Division 3 of Title 2 of, and Section 11513 of, the Government Code. A full and complete record shall be kept of all proceedings.