Let's talk about why engineers and architects think the best way is to make a big hole in each floor.

Because they are engaged in engineering or construction, not elevators ~ ~ ~ They need a shaft to install elevators, but in fact it is impossible to know all the details of civil engineering-it is not enough to have a shaft, but also a pit.

For them, opening a floor in the building as a shaft can borrow and rely on the original beam-column wall structure, and a part of the secondary structure can be formed. The workload is relatively small. If you don't have to destroy the facade of the structure indoors, you don't have to plan for approval, and you don't have to consider the secondary waterproof protection of the external wall, which saves a lot of trouble. Of course, I also recommend it-if there is enough indoor space ~ ~ ~

But the problem is that there is generally not enough room indoors-this is not the width and depth of the shaft, but it is easy to meet. This space refers to the bottom pit of the shaft, that is, the lowest level position, at least one meter and four meters ~ ~ This is impossible for the built building-either it is impossible to break through the foundation raft and dig down at the risk of water leakage (generally dare not do so), or it is the next one.

These conditions will be much better if you do elevator plug-ins. As long as there is no water, electricity and gas pipeline in the underground garage civil air defense project below, you can dig as much as you want, and you can find a place to put it as long as you don't block someone else's gate passage for lighting. Very convenient. Moreover, if the structure outside the empty building is made, the site construction is much more comfortable than the humble one inside the building, and the hoisting is also convenient ~ ~ ~ but the biggest disadvantage is that the structural elevation is changed.