Entrar escalonadamente en un edificio

[ROBINDESBOIS]

How can we say escalonadamente in this context? thanks

[poli]

If what you write means means, entrar el edificio por las escaleras you would say, enter a building using the stairs.

[ROBINDESBOIS]

enter a building step by step ??? or just enter a building gradually ?

[poli]

you can say: to slowly enter a building step by step. Entrar un edificio lentamente paso a paso.

[ROBINDESBOIS]

I mean, a group at 10, another group of 5 at 10.20 etc....

[Rusty]

Enter a group (of 5) at a time, twenty minutes apart.
You can change up the numbers as needed.

Or, without specifics beforehand:
Enter by groups, as directed.