Should you have Venue Template in your account, you will have the ability to upload a the template into an event after it has been created. Doing so will import a copy of all Sections on the template into your event.
This will be helpful should you:
Have a venue change
Need to reset edits you have made to seating plans
Reinstate deleted sections that you initially didn't intend to sell
Created your event before having the seating plan created
To upload a venue template into an existing event:
From the Dashboard, click on the name of your event under the Manage Event Overview
From the left side menu, select Sections under Allocation
Click Import a Venue Template
Select the template you wish to import in the Venue Template field, and click Import
The section from the venue template selected will be imported into the event
Remove any sections that you no longer require by selecting and clicking Remove Section
For more details on Venue Templates, see: Venue Templates