Create buildings easily within the Unity Editor. BuildR 2 allows you to generate a building as you want it. Using procedural generation, create large and small buildings that can bring life and fill out your levels.

• Customise textures, dimensions, styles.
• Generate building interiors, rooms, cores and stairs.
• No grid, make buildings freely as you want.
• Creates colliders out the box, walk inside your creations!
• Curved facades
• No need to run your scene to see your building.
• Fully integrated into the Unity IDE.
• Source code included.
• Supports Substance textures

This is the latest I could grab, works on Unity 2019 fine though.