Easily customizable procedural material which helps you to quickly generate different kinds of city windows.
Eevee + Cycles
Works well from long and middle distances. (For concept art mostly)

Mark the material as an asset. It will add a cube which is responsible for the texture's scale in all your scene. 
Then just open the material nodes and play with the settings! Hold Shift while moving the sliders or just type values manually, Blender's sliders are quite naughty.
There are 6 presets in .blend file but you can generate thousands of more unique designs.


Just like before, grab it for free or choose a payment option if you want to buy me a coffee:)

Inspired by Julien Gauthier's workflow in Octane https://www.artstation.com/renart

v2.0.: Can be used without UV's. Scale the cube (adds to the scene) to change the texture position on all your buildings simultaneously