It seems all the pieces are in place to allow player housing to be crafted. All the craft skills necessary exist. The inclusion of a few new resource node types - stone, for example, would be needed along with a positioning system similar to what exists for lawn items, trees, etc.
The only other requirement would be the creation of a range of house "recipes" but I wouldn't be surprised if this already exist as alternative designs dating back to pre-release. Even if they did not, the opportunity to have these very expensive and craft material/crafter-intensive vanity currency sinks in the game would seem to have irresistable appeal to both players and Turbine.
Exteriors and interiors could even be "mix and match" allowing greater customization. Any artists care to post their alternate Middle Earth Housing designs here?