Thanks for the reply.

I saw the existing guideline but to my mind it lacked the visual part :)
I also don't expect anything to enter the game its just like I said the models shouldn't be rushed. I think its a good thing to put some planning into the graphics before modeling...
If there is a set of chimneys ready it will be much faster to model them and then put them in the buildings.

Also I understand the argument about the finished work but I think there must be a way to have a consistent visual appearance. There must be a kind of art direction. I also understand that there certainly can't be one person deciding that this is why I had the idea of a style guide. You want steam punk? So, design some steam punk elements like chimneys in the style or a roof with cogs looking out.
This way later the development of new structures is not about a single artist doing a single building in his style but its choosing the different elements. For example you want a house? Choose a wall style (like the one I attached) then take a roof (our clonks normally use wood tile (or whatever we decide)). So you have the basic building finished in a consistent style and you can add elements specific to the building. In real clonk world they wouldn't think how to build windows every time they need one so we also have a window style.

So I would be glad to have a discussion about clonk culture in terms of graphics. How do they make liquid containers? Don't like my idea? post photos or sketches of an alternative style like a wooden barrel or so. then we could change the Liquid wagon, the Liquid storage and the barrels to that style.
I just offer to compile this ideas into concept art. i think modeling will be much easier later because there the problem is less how you model but what to model.

I can actually also model but I have no experience with low poly modeling so far.