Oskar Świerad published a wonderful 30-minute tutorial, which will teach you how to create good-looking procedural buildings for UE4 games.
It’s a 30 minute journey into the workflow, which allows you to generate realistic buildings in Unreal Engine 4 in seconds. This tutorial covers the main things you need to do in Houdini, how to make everything work with Blueprints in UE4 and ways to make the shaders work. It’s not for newbies, but if you’re interested in exploring the procedural tech (you definitely should be), this is a great place to start.
You can also download all the materials used in the tutorial for free. This workflow works beautifully for typical living multi-storied buildings, but it’s also applicable to other types of architecture. All files in this folder and its subfolders are licensed under CC-BY 4.0, which means you are free to copy and redistribute them, use and remix them for any purpose, even commercially. Just mention Tech Art Aid in credits.