All hearings of the Board of Appeals shall be open to the public. The decision of the Board shall be made within 75 days after the date of the filing of an appeal, application or petition, except in regard to special permits, when the decision shall be made within 90 days after the public hearing. Failure by the Board to act within said 75 days shall be deemed to be grant of the relief, application or petition sought, subject to an applicable judicial appeal. The Board of Appeals shall cause to be made a detailed record of its proceedings, indicating the vote of each member upon each question or, if absent or failing to vote, indicating such fact and setting forth clearly the reason or reasons for its decision and of its official actions, copies of all of which shall be filed within 14 days in the office of the Town Clerk and shall be a public record, and notice of the decision shall be mailed forthwith to the petitioner, applicant or appellant, to the parties in interest designated in MGL c. 40A, § 11 and to every person present at the hearing who requested that notice be sent to him and stated the address to which such notice was to be sent. Each notice shall specify that appeals, if any, shall be made pursuant to MGL c. 40A, § 17 and shall be filed within 20 days after the date of filing of such notice in the office of the Town Clerk.