Section 8. If an owner, lessee or mortgagee in possession of such unsafe structure refuses or neglects to comply with the requirements of such notice within the time limited, and such structure is not made safe or taken down as therein ordered, or made secure, a careful survey of the premises shall be made by a board consisting in a city of the city engineer, the head of the fire department, as such term is defined in section one of chapter one hundred and forty-eight, and one disinterested person to be appointed by the local inspector, and in a town of a surveyor, the head of the fire department and one disinterested person to be appointed by the local inspector. If there is no city engineer in such city or no head of the fire department in such city or town, the mayor or selectmen shall designate one or more officers or other suitable persons in place of the officers so named as members of said board. A written report of such survey shall be made, and a copy thereof served on such owner, lessee or mortgagee in possession.