I'd be interested to know if this was possible as well. My understanding is that you can't do this as the fields are controlled at the "module" level (eg SPM) and the templates you create all share the same fields. As a workaround we have conditioned the visibility of fields in the overview so that at the Project create stage, certain fields are only available based upon an answer given in another field.
The simplest example is that we have a UK and Non UK set of fields, if I select "UK" from our region field I get one set of fields visible if I select non UK I get another. This works well for us but if you could restrict fields at a template level it would be much more flexible.
Hi Molly, templates are made available based on the values to the fields inputted while creating the workspace. However you can create "Questions" which will show up after selecting a template. These questions can be used as conditions as well. Take a look at p. 38 in the Project Template Guide for more information on "Questions" to see whether it will meet your need.