2rahulkul2003: Try to apply different materials - like for roof - apply wood planks or tiles or metal, for trim of well , etc + Bake ambient occlusion and add it to diffuse texture and specular, and you ref model be cool
Some tutorials
Ambient occlusion by Sampson
Creating Specular/Normal Maps by Tiros
Whats an Ambient Occlusion Map
Sorry for my english
Many thanks!