When to use sub views with Emberjs

Hi guys I plan on having a layout that looks like this:

http://ift.tt/1Xg9R2U

This is my first Ember app and I'm mainly curious when I should take advantage of th sub views with

My question is, should I make the navbar and the entire chat view on one page

Or should I make the navbar and then have a sub view which will be the chat window.

When I click different chat links I don't want the page to refresh I just want the chat window to reload with the chat from the active chat.

This will be my first Ember project and I'm just wondering which way I should lay it out, I read through the Guide which was very helpful but like I said I don't know if I should make the Navbar/Chat on one template or if I should make the navbar and then outlet the chat screen. Any information would be great thanks