I was approached by a courier in Riften and given 3 letters. The consider adoption letter, breezehome furnishings and a letter from the steward of Falkreath. Does anyone know why it's just Falkreath I can buy land from? I'm not a thane in this city due to me not being able to assist anymore people in Falkreath 2/3. I really want to build a stone mansion in the snow in Morthal or Dawnstar. I realise the DLC is just out but any advice would be appreciated.

Just go to the jarls. Understand that we are under the impression that the houses will look the same regardless of the hold though.

I've spoken to nearly all of the jarls. The only one that allows me to buy land is in Falkreath and that's the only one I got a letter from. Also I've seen a few different houses made of different materials in the trailer so im guessing the materials available to build your house depend on what hold you buy land in.