Why is the minimum size of a column 300?

Considering the bearing capacity, 300 is the lowest. If the impact resistance is less than 300, you can. Too small column cross-section size will lead to lower reliability, such as negative size deviation and other factors leading to a significant reduction in bearing capacity.

In some rural self-built houses or villas, including the setting of buildings, columns may be set up.

About column selection:

If the column size is generally 40×40 cm or 50×50 cm in the frame structure, if the column spacing is relatively large, 60×60 can be selected.

If the masonry structure is selected, this column will not play a role in stress. Generally speaking, columns need to be set in corners or wide windows, and the general column size is 24×24 cm. Some of them belong to constructional columns, and the size can reach 18× 18 cm.