How to save the result of a t4 template in a different folder

When I try to give an absolute path for the generated files using

someTemplate.RenderToFile("c:\\tmp\\filename.ext");

      

        
        
        
      

    

I am getting the following error

Error 263 Starting conversion: System.Runtime.InteropServices.COMException (0x80004005): There is already a file with the same name in this folder.

although the folder is empty.