[buboy auxilio]

How can I compute the electrical load of a building intended for office space with some industrial machine in use

[sarnian]

Hello buboy

That is more a case of "how long is a rope" question.
There are so many different parameters involved that it is impossible to answer this question with any serious validity.

How big is the building?
What type of lighting is installed?
What type, power, and quantity of industrial machines?