Is it necessary to pile 20 meters deep in rural self-built houses?

This is necessary. If there are more than ten floors, you need to drive such a deep pile. There is no need to pile up so deep to build your own house. There is also a need to look at the soil quality of the building address, such as places with large water content and loose soil. If you want to be stronger. It is possible to build a house with reinforced concrete cross-pouring concrete structure underground. If the soil is solid and stable, pouring concrete hoop is enough. Rural self-built houses are only 180 square meters; Even if you build six floors, you don't need so many piles; In my opinion; 18-20m is correct for each pile; But there is no need to drive so many piles; I live here on the sixth floor; It is a three-unit building. I saw it when it was first built; There are few main columns in such a big place here; I walked about 20 meters before I saw a pillar. So; I think you can consider reducing the number of columns.