At the hearing the petitioner and other affected parties shall be given an opportunity to be heard, to present witnesses or documentary evidence, and to show why an order should be modified or withdrawn, or why a dwelling should not be condemned, vacated or demolished or why an action or failure to act by an inspector or other personnel of the board of health should be reconsidered, rescinded or ordered. Failure to hold a hearing within the time period specified herein shall not affect the validity of any order.
105 CMR, § 410.853