149.This section applies where a notice has been served under section 73 and the period specified in the notice has expired. It provides that an authorised officer of the local authority may enter the premises to determine whether the steps specified in the notice have been taken, may take any other person authorised by the officer, and a constable (if the officer has reasonable cause to expect serious obstruction in obtaining access). The authorised officer entitled to enter premises must show authorisation, if requested. In addition, an authorised officer who enters unoccupied premises must leave the premises as effectively secured against unauthorised entry as the officer found them.