Editions supported:  Site templates are available in Google Apps for Business and Education. Compare editions now

If you prefer to not use Sites templates in your domain, disable the Templates feature altogether:

1. Sign in to the Google Admin console.
2. Do one of the following:
   • In the classic Admin console, click Settings > Sites.
   • In the new Admin console, click Google Apps > Sites.
     ^{Where is it?  Which Admin console do I have?}
3. Click Templates.
4. Uncheck Enable custom templates and click Save Changes.

When users create a site, they no longer see any templates to choose from. In addition, the Publish site as a template option is no longer available on any site's Manage Site > General page.

To make templates available again (including any templates that were previously published in your domain's private gallery), just re-check this option.