A new harbour office could be constructed in Alderney, if States members give the go-ahead.
The States General Services Committee is asking members to approve spending more than £600,000 on the demolition of the current office and the construction of a new one.
It said vermin and leaks in the old building had led to damage to electrical and navigational equipment.
The States is due to discuss the issue at its next meeting on 19 December.
The committee said a company had already been chosen to carry out the work, following a tendering process.