Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Modern buildings pack Free.
Modern buildings pack
This is a set of 6 models in the same style, sharing the same materials and textures. It comes with 2 diffuse textures – day and night, with specular alpha channel and normal bump texture.
Small Building: 958 polys
Middle building: 3742 polys
High Building: 15066 polys