You may need permits or other approvals before you can start the work.
From the Tasmanian Plan Build website:
There are rules around planning and building and plumbing work that will affect how you can use the land, where you can build, what you can build and who can do the work.
A particular use or development that is exempt from planning approval does not mean it is necessarily exempt from building or plumbing approval.
Please check with Council before you begin work if you are at all unsure.
Plumbing Approval Form
Other Resources
More information can be found on the following websites.