The Berejiklian government has sought to reassure staff and the public that the dissolution of the Office of Environment and Heritage won't compromise the independence and services provided by it.

Fears by OEH staff that their roles were being made redundant were fanned by a statement sent by Treasury Secretary Tim Reardon on Monday telling staff the office would cease to be an independent entity and its functions would "transition back" into a broader Planning and Industry cluster.

How Planning and Environment resolves key differences - such as the competition between nature and housing demand on Sydney's southern fringe - will be closely watched after the Berejiklian government's reorganisation. Credit:Cole Bennetts

Those concerns weren't eased by a statement on Tuesday sent by OEH chief executive Anthony Lean implying he had few details of what the changes would entail.

"I am currently seeking clarification on the impact to the heritage function...and [will] endeavour to provide further information to you as soon as I am able," Mr Lean said in a letter to staff.