A regular everyday house that people live in is based on the human body. A rectangular kind of house with a peaked roof like this one.
There are two main parts to the house. The rectangular walls of the house, and the pyramidal shape of the roof. The human body can similarly be separated into a rectangular section and a pyramidal section. Here is a comparison picture of a house and a human being.
The scale of the house and the man have been adjusted so that the roof of the house approximately aligns on the boundary of the man that is the inspiration for the design of this type of house.
If a person engages in various body changing exercises, their body will change so that it feels as if it can be separated into two different areas. The rectangular shaped area of the legs, and torso of the body, and the pyramidal area including the shoulder and head.
The pyramidal area of shoulders and head will become very hard and rigid. It can be described as feeling like a covering over the rectangle of the torso and legs. The same way the hard roof covers and protects the house underneath. The picture below is a close up of the human being. The exact areas of the shoulders and head are outlined in red. This is the inspiration for the roof. The green box emphasizes the resembland to a rectangular building underneath the roof.