Hi,

i'm not sure if you find out your answer and if your question was clear but as it looks, you can design this wall in different way.

1°) you can design it as an architectural wall and add niches for vertical joins and polygonal niche for horizontal joins. For the horizontal, you must place them in the side with a small thickness and than modify the length manually.

2°) or you can design it with 3D modeler and add you joints by substracting the joins with a 3D object or an extrusion tool.

If necessary, you can convert your 3D object to an U-D element (user defined element).

Please find an example below for the 3D body.