Is it wiser to have a static header, menu and footer and load center content dynamically or vice versa?

Question

When designing pages for a project that uses dynamically loaded pages/content (the website will not be accessible to search engines, so that's never a concern. Only for desktop PC use. Not for mobile phone use. Using Spring MVC), is it wiser to:
1. Create a page with a header, menu and footer and dynamically load the content in the center, according to what the user chooses from the menu?
OR
2. Create separate html pages for the header, menu and footer and design a dynamic page which with center content, that will dynamically load the header, menu and footer?

• A priority for this project is to use up as less of the network bandwidth as possible.
• My main concerns are that if I use iFrames to load the header, menu and footer, there might be problems when resizing the page.

Doesn't GMail work by loading only the center content? Do you know how they manage to allow the User to use the back button of the browser inspite of the content being loaded dynamically?

This is what the layout would look like:

Answer 1

Depending upon your requirements (low network bandwidth), I think splitting your website is such a bad idea since it will result in many requests. I don't recommend dynamic loading for navigational purposes since the headers and menus are only lightweight.

Here are the answers to your questions:

1. Maybe. It depends upon the size of your dynamic content and static content.
2. There is not much difference to your first question. Separating content into parts is good idea and makes your code readable and maintainable. I would recommend splitting it. But, again loading dynamic content depends upon the type and size of the data.

If you want the back button kind of functionality, then go for AngularJS.

Hope this helps. :)

UPDATE: In that case, you can combine the static fixed assets, and then load the content dynamically using jQuery if there is no need for data persistence(like Gmail back button). Try checking out SPDY - think it will reduce network latency.