Power of entry.

The Board may authorize any person to enter into or upon any land or building with or without assistance of workmen for the purposes of,- (a) making any enquiry, inspection, measurement or survey of land or building; (b) examining works under construction and ascertaining the course of sewers and drains; (c) digging or boring into the sub-soil; (d) setting out boundaries and intended lines of work; (e) marking boundaries and lines by placing marks and cutting trenches; (f) ascertaining whether any land is being or has been developed in contravention of any plan or in contravention of any conditions subject to which such permission has been granted; or (g) doing any other thing necessary for the efficient administration of this Act: Provided that,-