Could anyone help me with the types of houses and structures found in Afghanistan, also any advice on the materials needed to make these structures (1:35 scale) would be very helpful.

Blue foam is great for making the buildings coated in filler

Hansa Models do this

Is the blue foam insulation foam? I have no idea where to get this stuff.

Yes - try builders merchants or online

You can go to home depot, Lowe's and menards.
It is called blue/pink dow. It usually comes in 4x8 sheets in different thicknesses.

Mike

This is compounds from Helmand :


HTH
Heinrich

You should get some Balsa foam .
https://www.google.nl/search?hl=nl&biw=1920&bih=963&tbm=isch&sa=1&q=balsa+foam+australia&oq=balsa+foam+australia&gs_l=img.12...1650.6684.0.8277.14.13.1.0.0.0.113.943.12j1.13.0....0...1c.1.64.img..10.4.271.1QxVN5kTPW0

https://www.google.nl/search?hl=nl&biw=1920&bih=963&tbm=isch&sa=1&q=balsa+foam+&oq=balsa+foam+&gs_l=img.12..0i19l7j0i30i19l2.14283.14283.0.16765.1.1.0.0.0.0.85.85.1.1.0....0...1c.1.64.img..0.1.83.R2kPm1SjUMA#imgrc=427yHaPezXB-3M%3A

There are vast differences in architecture, especially between urban and rural settings. When I get on my other (non iPad) comptuter I can post some up. One of the most interesting things I saw was the use of vehicles lying on their sides used as walls.