I am watching a concrete/brick house being constructed next to the one I rent and wonder about techniques on how to connect the roof with the foundation columns. I think my neighbor has a typical thai-style solution (see attached pic) but I am not sure I like what I see. The weight of roof rests on the rebar wire inside the columns and not directly on the concrete itself... I plan to build myself in the coming years and will most likely have to deal with local builders so I am curious about different solutions here, seems important.

What is in your view a preferred technique to connect the foundation columns to the roof?

Seems to be the standard method in Thailand, although not ideal it seems to work. My suggestion would be to fill any gap between the concrete column and the roofing steelwork with non-shrink grout. Have a good check of the weld quality, remove all the slag, wire brush and apply a couple of good coats of red oxide.

Thanks, non-shrink grout - seems indeed like it would make sense for my neighbor to add some of it to that empty space. Had not heard of it before!

The main problem is not in just welding the roof structure to the rebar of the column tops. It is the lack of lateral bracing of the columns under the roof level with cross beams.

Draw a 6-sided cube. Now erase off all the horizontal lines at the top of the cube. What is left will be columns that can freely bend.