(a) The Commissioner and the various officials delegated by him to carry out this chapter shall have the authority at all times of the day and night to enter in or upon and to examine any building or premises where a fire is in progress or has occurred, as well as other buildings or premises adjacent to or near the same. The Commissioner and his delegated authorities shall have the right to enter in and upon all buildings and premises subject to this chapter, at any reasonable time, for the purpose of examination or inspection.

(b) Upon complaint submitted in writing, the Commissioner and the various officials to whom enforcement authority is delegated under this chapter may enter in or upon any building or premises between the hours of sunrise and sunset for the purpose of investigating the complaint. Upon the complaint of any person, the state fire marshal or his deputized officials may inspect or cause to be inspected all buildings and premises within their jurisdiction whenever he or they deem it necessary.