"Hey, here are several changes I would personally make to the model:
1. You should work on the stone cuts. The edges of the house are perfectly cut, which makes the building look kinda fake. I would probably put them one by one, so I can achieve more of a realistic effect. You can also use the defuse filter and the normal bump to achieve better results.
2. Something else I would personally work on is the ambient occlusion effect. It will give the model some depth.
3. I would suggest using UVW Maping as well. It's a great way to give the structure some curves here and there.
4. The water needs some work as well. Some additional spills and drops around the wheel will do wonders.
5. And last but not least use Z Depth Pass."