PlusSpec has many different types of wall types that you can use and adjust to your satisfaction! We also provide different outer/inner wall types with varying sizes as well. But, sometimes this simply isn't enough!
If there are no available walls that apply to your measurements, you can adjust the wall thickness by creating materials for the internal and external walls.
This video below teaches you how to create tileable textures. Included in this video is the ability to adjust the wall thickness.