What does it mean by "build on a human scale"?

"Build on a human scale" means the priority given to human beings before constructing anything else.

Explanation:

Architect Jan Gehl gives a better explanation of what "Build on a human scale" is. Before building a pavement or a building or even constructing a car or a bicycle, people are first taken into consideration.

"Build on a human scale" means the priority given to human beings before constructing anything else. The space that is required for the people in the city is first calculated and than the other things are taken into consideration. If not, if people weren't give a thought and just build buildings and manufacture cars, the lives would be disrespected as well as considered not important which would put an engineer at high danger.